TRANSCRIPT

The format for today is a little bit different. I prepared a small presentation, but we'll be spending a bit more time with live models and question and answer type of things.
So I went through and took a look at all the live or all of the requests for today. I haven't been able to create fully functional models for all of them.
I think the two that I don't have fully functional models for are, at this point, our radiant systems and desiccants, but I will share models with you after class that show those two systems. So today we're going to talk about, first, we're going to talk about utilities and economics.
Somebody dropped that in yesterday and I thought that was a great idea that we haven't talked about utilities and economics yet.
Number two, we're going to talk about incorrect operation and we'll use a fan coil system as an example.
This model was super interesting to set up, so I hope you like exploring it with me.
Number three is energy management system and Python plugins, and those are programming languages that you can use to make changes to your file as it's simulating.
And we aren't going to do, I can show you an example file. We're not going to do a fully fledged example. I'm showing you this because I want you to know that it exists and that it's there.
But we also are going to talk about all the different ways that you can do what you need to do without using energy management system. It makes your models and times more difficult to troubleshoot.
So I say use the regular energy plus tools first and if you can't do it, then start exploring these.
Okay, so we're going to look at the geothermal heat pump example. So that's one of the example files that I created that has the water to water heat pump geothermal systems.
And actually, I don't think we're going to talk about operation schemes, but we'll go through some live modeling examples and potentially look at the solar hot water and domestic hot water example from yesterday that we didn't get to.
Okay, so currency.
There's a whole section and energy plus on economics. So they have
There's a section on currency. So.
Currency and component costs. So you can actually do cost estimation for your project in energy plus.
There's utility costs.
A bunch of different ways to.
To model and define your utility costs and then there's some life cycle cost parameters as well. So you can have energy plus inside energy plus do all of your life cycle calculations.
Currency and estimating. Okay, so currency type. You can just switch between different types of current currency, which I think is really nice.
The default is USD. So if you don't use this object, it will just stay in USD.
Component cost adjustments.
So you can this is these next couple of objects are used to create a like a budget and estimate.
So these are all kind of like your miscellaneous fees and contractor fees and all this all this kind of thing.
And then
Let's see.
Hang on a second here.
Okay, I apologize. I had a just a little notification pop up that my connection was unstable. And usually that's when
Some equest files try to sync.
And it's really slow and they're huge files. I don't know why they're huge files and they try to sync and it slows down my connection. So I just had to turn that off.
Okay, so this this item I thought was, I think it's pretty interesting. It's a way to give yourself a baseline in the same model file. So component cost reference.
I think I don't think it's a particularly useful object, but I want to be today was a little bit about sharing different parts of energy plus so that you know where to go when you have a question come up in the future where you're like,
You know, it'd be nice if I could add a couple parameters and just get the total cost estimate for the project. That would be fantastic. So this is this is where you would go.
And then the component cost line item.
These items are actually linked to
Objects in your model. So
A lot of these are related to constructions. So it's a construction. There's the name of the construction and then they're giving it a dollar amount per area.
And and then there's also
Something linked to the chiller where they're giving it a dollar amount related to the capacity. So some of this stuff can update as your equipment sizing changes, which I think is just
Kind of fascinating.
Utility rates.
Again, this is energy plus that they're going to throw a lot of different objects at you.
Take a look at some of these ones. I'm going to show the ones that we use principally and the other ones can create more complex utility cost
Structure.
But you really only need two objects. So this utility cost tariff object that defines the tariff and links it to a meter. So we'll talk more about that on the next slide.
And then you need a utility cost charge.
Or you need at least one of these
Charge objects. So they're simple. There's block and then there are different ways to model ratchet variable. This one you can actually do computation and do calculations on some of your utility variables.
I've never I've never actually needed to use any of these. These two are really quite
Quite flexible.
I would chime in because I reviewed a lot of files.
And I've reviewed them for numerous different applications. And in the chat I mentioned that probably 98% of the files that I've reviewed have used this simple option, which I think is a little bit of a shame.
But just as a note for this presentation, I think most of the time people are using simple in energy plus it's probably a higher percent that use
You know blocks and so on. However, I have not ever seen I've never reviewed a file that uses any sort of complex right.
It's good to know that it has that feature though.
Yeah, yeah, I mean, and on these blocks.
So this is a this is a complete utility example, which is not super super simple, but it's fairly simple.
The utility cost tariff.
You need it needs a name and then you can choose a meter. So there are some default meters that are available in energy plus that are automatically created. So there's electricity facility. That's the entire facility. There's electricity building.
So that's just the building it would include anything that's outside of the building like exterior lights.
I think there's also like for all of your sub end uses electricity lights electricity.
There, there's a big long list in the input output reference. You can also create your own custom meters. So you can add and subtract and actually we could we could take a look at that if if you like if there's interest.
But you can sum up say, for example, the electricity used by your cooling coils in your watered air heat pumps on floor number 10 and
say compare, you know, charge an additional electricity rate for that particular and use. I'm not sure why you would, but there are some projects where you have
like a particular use case particular example of this is a project where you might have a different rate for a residential portion of the building versus a commercial portion of the building and so you might need to
you might need to sum up all of the end uses in the residential portion of the building and subtract them from the total and that way you get a residential meter and a commercial meter and you can apply different electricity rates to the two of them.
So this is this is what the meter is. I can actually open an example file and show you how that how that works.
You can you choose your energy conversion so this is whatever units you're going to be using in your utility cost charge objects. So make sure you choose correct units because if you're if you choose nothing it will be joules I don't know anybody who sells energy in joules.
And our utility cost charge. So we link it to the tariff with the tariff name, and then we we choose a source source variable so that here we have energy and demand that we can also do on and off peak energy and demand in these.
There's some more complicated variables here.
I can choose a season.
And then there's energy charges demand charges there's some other categories. And then this is really interesting here this remaining into variable.
Any energy that's left over so you see let's let's come back to this little bit so.
Here we have blocks so we can say the value of a particular block and how much we're charging for that particular block and then the next block and how much we're charging and then the remaining and how much we're charging so this field right here.
This field remaining is an unusual field in energy plus because most fields require either a string or a number in this field can can choose either. So if you don't have remaining and there's something left over.
You can put it into another variable so that's what this remaining into variable is and then create another utility card charge block or ratchet or you can do some sort of sorts of calculations with that information so.
Again, I've never seen it used today is a little bit about sharing with you what is possible. So if at some point you have a complex utility rate structure that you need to describe.
You hopefully you'll remember some of this and know where to look for that.
One question came in here. Yes. Yes.
Can we add a steam meter with a utility right even though there is no steam loop in EP 3.
Yeah, you can you can do a steam meter but we're not currently supporting steam so if you were making a model in EP 3 you wouldn't have steam.
If I'm trying to remember why we're not supporting steam I think they're just EP 3 development has been driven by the people using it and the people using it haven't been big on.
Or haven't had a lot of projects related to steam so if if we have users that are using their need having need for steam we can we can think about implementing it but yeah yeah you can definitely make a meter related to steam.
Or an utility rate related to steam for sure.
And the other input that I would add with this sub metering where it's probably important to the people watching this is for calibration.
Yes, yep. Yeah, I tend to do calibration with with output variables which is what we were looking at with the graphing.
But if you have if you have larger projects with large blocks and you're looking at data over longer time periods than the.
Then creating a meter and a custom meter that can aggregate everything and be very useful.
Yep, that's the same approach that I recommend is to look at output variables.
I just know that that's an example where people sub meter frequently.
Yeah, absolutely. Absolutely. Yep.
Okay, so yeah.
So, if if you're using a variable name here, this is a block size or a variable, then so if we put right here fixed variable charge we could change that value over the course of the year.
Which I thought was like, there's so many ways to do complex utilities. So, anyway, that's a little bit of information on utilities.
And then life cycle costing as well.
We won't we won't go into this too much, but all of your all of the information to do your economic calculations related to life cycle cost are available directly in energy class.
They're not so much linked to the rest of your model. They're just sort of inputs. So you would need to make sure as you're doing change as you're making changes to the model.
That the life cycle costing reflected those model changes.
Okay, topic number two.
Let's have a little discussion about how do we model real buildings with faulty controls. So this was a special topic request that came in quite some time ago.
And I thought this was a great question. How do we model real buildings with faulty controls. And so the first, the first thing I'd like to discuss is what happens when they're faulty controls in an actual building.
So we could choose an example of the one, the one we're actually going to model is a piece of equipment that has thermostat that is conflicting.
So maybe it has a, a heating set point that is cooler than the cooling set point. So what actually happened, what is actually happening with the equipment when that happens.
Go out of this so I can add it here.
All right, any ideas.
Just waiting for people to type.
It doesn't work right when they are faulty controls.
Yeah, so
Energy consumption goes up. That's a yes.
A typical faulty control alternatively energy consumption turns off if the control turns the equipment off, but in general it goes up.
Yeah, it often goes up.
You can have and why, why would it go up?
Next answer is perfect overheating and over cooling.
Okay, over heating and over cooling.
And then obviously additional pumping energy is a common one additional pumping your fans.
Yeah, what about
Short cycling.
Yep.
That's a good one.
Why is this the alignment is kind of funny on here, but we'll go with it.
We can live with it.
We can live with it.
So we've got some short cycling other things.
For thermal comfort.
Yep.
What, what capacity is equipment often operating at
Oh, it operates at full capacity when it's really regulated.
Especially if it's oversized, it's auto sized, you end up with oversized and full capacity.
Ooh, that's a little nugget.
Okay.
But auto sizing would be simulation.
So we're talking about here, we're talking about like a real building.
Yeah, full capacity, but often, often those are oversized.
So you get the double whammy.
Yeah.
Okay, so
What effect does some of the stuff have on the simulation.
I am an hours.
It's a good one.
Seeing it.
Hi, unmet hours.
Hi, unmet hours. Yep.
An incorrect simulation.
Can you expand on that a little bit?
Well, let me think.
We had some other things come into so crashing the program thumbs in.
So this one I think is really interesting because a big complaint or a big challenge is with energy model.
A big challenge is with energy modeling is what we can't model incorrect controls.
So I kind of want to take this, this analogy between a real building and a simulation on, you know, what is the real building equivalent to crashing the program.
Yeah, I think that goes in line with operating the model simulates incorrectly because it can't simulate a broken building very well.
Yeah.
Simulations generally assume that the model that the building operates under normal circumstances.
Yeah, and I think I think one thing that's important to remember is that if I mean models are hard enough to troubleshoot as they are imagine if things didn't operate correctly on purpose.
How much more complicated how much more difficult would it would it be to troubleshoot and this sort of real world.
Analog to a program crashing might look like a piece of equipment.
Short cycling or swapping back and forth between one mode to another until it wears itself out.
So this is the program crashing is is kind of like the the building not knowing what to do, except it doesn't just turn itself off and give up when it keeps doing the same thing over and over and over again.
I think a lot of these a lot of these things are well some of these things what we're going to model today is kind of like an endless loop in in computer programming.
So a loop that never ends like a piece of equipment that has a heating set point that's below the cooling set point it is never going to resolve what the temperature in the space would be.
So actually that could be something else we could have like a poor, poor thermal comfort is right up here.
Selectuating space temperatures.
But for for energy plus to move from one simulation step to the next simulation step, it needs the space temperatures.
It needs the node temperatures to resolve it's it's modeling in kind of a circular fashion where the inputs of one thing lead to the outputs of another thing.
And I think I can actually think there's some and then the outputs are used for the next inputs.
Yeah, exactly.
I mean, so it's it's.
It's prettier but it's it's doing this essentially it's saying you know the the zone temperature is here and then we have some return conditions and then it gets mixed with outdoor air and then we try to meet this thermostat set point and there's another thermostat set point that's different and then it comes back here and and these are fighting where we're never going to get stable conditions at all these nodes and we're just going to stay in this cycle.
For the first 15 minutes of January 1st and we're never going to get anywhere and that's why the program crashes whereas whereas with an actual building we do have have time so it's going to just keep doing that and in this endless loop but time will pass but in the simulation time is, you know, our time and simulation time are different.
So I hope that's not completely completely confusing explanation, but I think that was that was great. Let's move on to the next thing.
So we need to get kind of creative to model faulty controls.
So I think I think a lot of times we get stuck on what the controls are telling the building to do.
And it's much more useful to think about what is actually happening in the building because the when controls are faulty the controls are telling the building to do something that it can't actually do it's trying and it can't actually do it.
So if we want to simulate the energy use of what's happening in the building. It's, it can be really helpful to look at what is actually happening is the is the temperature fluctuating are the dampers dampers opening and closing is is a valve stuck open.
What is, and then we tell the simulation to do what is actually happening in the building we don't give it the same controls.
scheme that the building has because it's causing problems and it's probably it's it's sort of crashing the building it's probably going to crash our program.
So here, there are a couple techniques as well so what.
So we're trying to figure out what is actually happening so we can model what's actually happening not what the set points are.
Use of real world data to create custom schedules so that the schedule file approach that I showed you last week is a great way to to model some of these variable weird conditions.
Try to achieve the desired result first using regular energy plus and some some creative use of set points and thermostats and equipment.
And then you can try with energy management system or Python plugin so we'll discuss this in a little bit what what this is when and how you would use it.
And then you would go to to post processing I would say validate validate validate validate especially with energy management system and Python plugin.
And you need to define what's close enough to provide valuable data because this is one of those situations where the simulation what's possible in the simulation and what is happening in reality diverge a little bit.
Okay, so we're going to take a fan coil model.
And we'll take a look at some faulty controls.
Okay, our fan coil model. So this should look familiar to the model that we worked with a couple days ago and we talked about zone HVAC equipment.
We have our hot water loop. We have our chilled water loop condenser water loop, which is serving the chilled water loop, and then we have a fan coil.
In order to test the system and test my theories I've made a very, very simple building so it's just a quite small one zone office building and I created this using the wizard.
And then I wanted to test that theory of what happens if the thermostats if if the zone, I'm sorry, if the fan coil has a heating set point temperature that is higher than the cooling set point temperature.
And so I thought for a while about this and I thought, you know, what, what can we do we can't actually give two different thermostats, we can't give two different pieces of equipment different thermostats.
Not, not directly in energy plus. So what can we do, I thought well the next best thing would be when I accidentally deleted the file that helped me generate this, but the next best thing would be
to have a thermostat that oscillates.
So I generated a thermostat that there's, there's a couple.
This one oscillates every 15 minutes from a, a higher temperature to a lower temperature. And this building has no dead band. This is the temperature that the space is being conditioned to there's just one temperature.
This is a heating temperature and the cooling temperature and it switches between 7470 every 15 minutes.
I did another one that switches every single minute.
So for every minute of the day, it switches from a high temperature to a low temperature and I used a spreadsheet to help me generate this because doing that by hand would be my name.
So this model has a couple of alternatives.
So the base alternative has a normal normal thermostat.
So the normal thermostat with a dual set point dead band thermostat. This is exactly what comes in with the with the wizard as a normal thermostat.
And then we have a simulation that's just a single set point thermostat.
So this type of thermostat is a single heating or cooling thermostat and I've just used the efficiency measures and energy in EP3 to just change the name of the thermostat in this object.
So here we have our, let's see.
This is our original thermostat, which has a heating set point and a cooling set point can actually look at those the heating set point here.
And the cooling set point here. So it's, it's maintaining conditions between 70 and 78.
And then our single heating or cooling set point. So there's just one schedule, just a single set point thermostat.
And I decided that what I want to do is I want to simulate one step at a time. So I see where which changes to my model are creating changes in my data and results.
So I went from a dual set point thermostat to a single set point thermostat. It just has this one condition.
And then I decided, okay, I'm going to do two simulations with with the thermostat fluctuating between high and low temperatures. So energy plus can simulate down to it can do iterations as quick as one minute.
So normally, each iteration, each time step is 15 minutes, but we can go as low as one minute. And so I was kind of curious, like, how, how close is that?
Obviously, it's not the same as two simultaneous thermostats, but is that is that close enough to give us an idea of the impacts of having two thermostats that are fighting.
So we have a 15 minute time step.
So we still have a.
Oh, I have simulated them all at 60 minutes so that we can compare data detailed time step data.
So we have here.
A different schedule. So it's the same thermostat, but it's a different schedule. So this is the schedule that I showed you that every 15 minutes it flips.
And then we have a simulation that is 60 for every minute for 60 minutes.
So I should have named it one minute instead of 60, 60 minutes.
But there we go. So those were my three or four initial simulations and the
these two efficiency measures use the single set point thermostat as base efficiency measures.
Okay, so let's take a look at some results.
So I can select to display already simulated files. So if you have file, if you have simulated like 10 different files and you want to compare results for say three of them.
This is a great way to do it. So I'm selecting the directory. All the files need to have been run simulated and saved in the same directory.
We can select a directory. And then it will give you a list of all of the the energy class files in that folder.
And so I'm going to select those four initial runs.
And we can take a look at our results.
I'm just going to take a look at the energy use. This is the first bit of information. Okay, so this is kind of as we expected the base efficiency measure uses the least amount of energy for cooling and for heating.
And then the single thermostat, the single set point uses quite a bit more cooling and a little bit more heating energy.
And then as we go along, it goes up until we get to the fighting thermostat. So the one that that switches every minute we're using a lot more energy. So I think, you know, first.
Our first blush is this is this is showing us some of the impacts of having thermostats that are not aligned.
Okay, so let's look at the time step information.
And I have zone air temperatures for every simulation selected.
There's a lot of data with data every minute. So it takes a second to update this data.
There we go. Okay, so let's take a look.
Yeah. Okay, now it's now it's a bit better. It's a little bit less. Okay, so we have our base zone temperature. So this is just the green line that is nicely switching from heating mode to cooling mode.
And then we can see the up and down of the 15 minute thermostat.
And then this orange line in the middle is our single set point.
And then we have the pink where things are just kind of going nuts going back and forth between a high temperature and a low temperature.
Okay, so I was looking at this and I was starting to think about.
You know, at some point, you're going to be meeting the maximum capacity of your equipment. So I feel like even if we went to lower and lower and lower time steps, we should sort of eventually reach a point at which we are sort of normally out.
We're not seeing any more energies, but realized that can only happen.
And that that will that sort of approaches the heating equipment and the cooling equipment operating at maximum capacity all the time. And I got me thinking about my auto sizing because everything is auto sized.
We go back to our fighting thermostat schedule.
Right here I have it defined for all days, which includes our heating design day and our cooling design day, or sorry, energy plus called it winter design day and summer design day.
So that means that the equipment is sized for this terrible condition. So I went back and said, okay, I wonder what happens if we do another simulation where we have just a single set point for our summer design day and our winter design day and then we have the terrible operation for all other days.
So we have this simulation has, I've called it reasonable sizing. And let's update our results so we can see it.
To select all of them. Okay, there we go.
You
Okay, so here we go. So the
green is the unlimited sizing
temperature swings. And this pink is the more limited temper sizing temperature swings.
So we can see that there's less amplitude happening when we've eliminated the equipment sizing, it's not going to get as far towards the other side when the when the thermostat changes.
And
if we look at this graph, we can see so the red now is that
equipment that's been auto sized correctly, and the purple is equipment that is way way oversized.
Questions, comments, I see a couple of things are kind of been up.
Yeah, the first one is, can we show simultaneous heating and cooling schedule, which might be caused due to faulty thermostats instead of switching between low and high set points.
So we can't directly and energy plus have different zone equipment that connects to different thermostats.
There, you could, there, there is an application where you can have space HVAC equipment and zone HVAC equipment and they can have different thermostats so you could do it that way.
But yeah, I think I think you could do it with space HVAC. I think I think part of the question is, what are you trying to show?
Because if the two thermostats are truly 100% opposite and opposed, you're just going to have the equipment operating at pretty close to 100% all the time.
So yeah, I think part of the question is, is what you're trying to do, what it is that you're trying to show, but the direct application is a more complex implementation that we don't have space HVAC implemented in EP3 yet.
I think, I think you could do it with energy plus, but I'm not 100% sure.
Okay, the follow up comment is that it can be connected to the same thermostat, but sometimes it is not communicating with either heating or cooling valve.
Is it possible to turn the mic on for the participant so I can hear directly what they're.
They can ask.
Okay, nothing.
Okay.
If there's a real specific application as well, we can communicate in the in the class forum or over email.
Yeah, the only thing I'm thinking is in a four pipe fan coil system, you could potentially have simultaneous heating and cooling, as opposed to like a heat pump or something.
Yeah, so that the other, the other way that you could do.
You can definitely do simultaneous heating and cooling.
Controlled to a set point temperature in an air loop.
Let me see if I have something.
Okay, so if I had in an air loop here.
If I had a.
Not sure what I had going on with this file.
I'm going to open another file, but if you had a if you had a.
Cold set point here and a hot set point here, then yes, you could.
You could have fighting coils in an air loop. Absolutely.
In zone equipment itself and having a two different thermostats, a bit less so you could use.
Actually, that is another way you could do it. I think, I think part of the answer is there's so many ways to do this and energy class. So if we looked at.
If we look at a file that has heating coils and cooling coils.
The user mentioned that they can chat about this in the form.
Yeah, we can chat about it in the form because I think it depends a little bit on what the, what the exact application is.
And again, I think today is about thinking creatively and understanding what some of the possibilities are. It's not about this is exactly how you do this one thing. And I think, I think how do you model incorrect.
Operation is a really big question. So.
Yeah, so we can actually go back to.
Presentation for just a minute and talk about.
Get the.
If, if you don't, well, it didn't mean to click there. We got our big, big reveal that early.
If all else fails and you cannot figure out how to model.
What you're trying to model that incorrect operation directly within energy plus you can use what's called energy management system. So energy management system is.
A way to create programs that simulate inside.
The iteration process of energy plus and it can.
It can allow you to create custom control strategies and you can change things.
According, you can change things in the model during simulation. So you can change internal loads. You can change set points. You can change the, the state of nodes. You can just set a node temperature to something else without.
Accounting for it in the energy balance.
It allows simulation of custom and complex control logic.
I, I see.
Some energy management system from that are sort of, it seems to be automatically generated by other user interfaces and I've stayed away from that because.
It can really slow down simulation.
But it has its place has its place and you can't do what you want to do directly in energy plus it does make sense to use it.
Some, some things can integrate with external tools.
It can be time consuming to set up.
And your model has to be valid. It has to simulate prior to adding EMS and scripting.
But yeah, be really careful.
Because you can implement things that break the laws of physics and I mean this is something that.
It's, it's kind of like.
You know, when you do a lead model, they ask you if you've done any external calculations and this is sort of like a.
Is it an external calculation or is it internal, but it's not a calculation that's been very, very verified. So it's an external calculation that happens inside the simulation.
So yeah, you can absolutely change parameters in the model.
And model incorrect operation schemes.
We'll talk just a little bit about.
The components.
You have sensors so you can read anything from a.
An energy plus meter. So any of the standard meters or any meter that you generated.
And any output variables.
You have to create an energy management sensor object in order to.
To read that data, but that you have a ton of data available to you for your.
For your.
Custom control strategy.
Then you have actuators.
And that overrides standard energy plus protocol and standard energy plus.
Calculations.
In order to know what actuators you have access to.
When you have your normal model before you add.
Energy management system you can use this output energy management system.
To get a list of available actuators.
Then you have your program, which defines the logic for the custom control.
You have global variables, which store user defined variables and to access them in different programs.
And you can also create custom output variables from global variables.
So that is really important for validating.
Your model functionality.
Then you have a program calling manager.
So it specifies when.
Program should execute their different options for when the programs should execute.
So there.
There's an option for executing during.
Each VAC system sizing.
There's an option for executing at.
The, I think it's like the.
Zone heat balance.
Level and then there's another option for executing at the.
System kind of sub iteration.
Level.
I would recommend.
If, if it's, if you're just changing a schedule variable, you want to go, you want to.
Actuate at the least amount of times possible. So.
Because having things that actually inside.
The.
Zone eight or I'm sorry, the, the HVAC iteration will really slow things down.
Okay, and then we have this output object.
And that creates a file called the MDD file.
And that gives you a list of all of the available actuators and internal variables in your, in your model.
One of those.
Open somewhere.
Don't actually have one of those.
You can take a quick look at one of these files.
Okay.
We have a couple of sensors in this file.
Let's actually look at the.
Okay.
We can look at the program.
This way as well.
Right. So we have actuator sensors related to lighting, boiler, the environment and ventilation.
And then we've actuators.
Related to curves. So this is a boiler curve. And then we're changing some schedule values.
So, I mean, this, this particular program.
They're using energy management for it. This is the sort of thing that could be done with pre-processing.
However, it's a relatively simple.
For example, and so we can take a look.
Okay, so this is the point at which you're calling the simulation program and they're listing programs. You can list a whole bunch of different programs, but they just have one or two programs.
So, inside the HVAC system iteration loop, this is where you would need to be if you were trying to set flows on a particular node and really force the program to do something that it doesn't want to do.
You would need to be inside the HVAC system iteration loop. It's quite difficult to.
Well, it's not necessarily difficult, but you need to take some care with what you're doing there so that you don't end up in a maximum iteration and program crashing situation.
And then the energy management system program, it says really horribly ugly language, but if you've done some programming, I'm not going to go through what all of these things mean or do, but I think we can, we can kind of see that the
like with the, with the curve, they're checking the workload ratio and they're setting a curve value based on workload ratios of the boiler for.
There's optimum start based on time of day.
Anyway, I, I, this is one of those things that I want you to know that it exists that it's here and that you can use it to do more complex things. I would encourage you not to start here.
If you want, I can, I can also show you there's some resources specifically about energy management system.
There's also, there's, I'm showing you energy management system because it's directly in energy plus, but there is also a Python plugin.
Which essentially, it does the same thing as energy management system, but there's a, let's see, there's a Python plugin.
So, instead of having the actual code written in an energy plus file, you basically create your, your variables, and then set a path to your Python plugin file.
So it's an external file. It's, it's Python, so it's a much better, more modern language, and you can create it in whatever developer environment you want to create it in instead of having to deal with the text file format in energy plus,
or we do allow energy management system in EP3, but it's, it's sort of, it's sort of.
It's somewhat supported, but it's not like super, super supported. So, if we have,
if we have variables that we want to select for a particular object, we can set an energy management system sensor name, and it will automatically create the energy management system sensor for this particular output variable.
And it's helpful to do it this way because if you have consistent names, then you can reuse parts of your code.
And so you might have some piece of equipment where the equipment name changes, but if the EMS name stays static, that can help you reuse your code.
So, it's just a, that's a, what is energy management system, I think, rather than anything close to how, how to use it.
Any questions or comments on this or particular applications you think you would, you would want to use it for?
I see it in a lot of example files and PNNL files doing things that could be done with the schedules.
Do you have any specific examples?
I have used it in the past. I don't have any that I'm ready to show at the moment, but I have.
There was years ago, before energy plus had a decent air to water heat pump model.
I used energy management to simulate or to run some calculations sort of inside the model to simulate like a central air to water heat pump plant.
So, you can have, you can have custom, what are they called, user defined.
Yeah, I was just curious if you, I'm sure you had something.
Someone asked going back to utility rates.
You had shown how to do that and energy plus directly, but can you show how to do that in EP3?
Yeah, okay. So, in EP3, the, I've shown it in energy plus because in EP3, it's really quite similar.
We haven't done anything special with it in EP3. It's just, it's the same objects.
So, you have your utility cost tariff and then you have your meter name.
Now, we didn't give a drop down here because we, there's so many different meter names available in an energy class between custom meters and internal variables and all that sort of stuff.
So if we give you a drop down, we're kind of limiting you to what we know about and not giving you the option to do things that maybe are a bit more creative.
Say, for example, any MS generated meter.
So if your meter name and then your utility cost charge block right here.
And those are the two, I think I've done 99% of the modeling with these two.
And you can get, you can get pretty creative with these.
Could you show quickly how to add something as simple as 10 cents per kilowatt hour as a flat rate?
Yeah, so if we did electricity facility, conversion factor would be kilowatt hours.
I think that's all we need here.
Now, we can have a monthly flat monthly charge if we want.
And then,
so if you
So it's very wrong.
It would be energy, it would just be energy.
And
Oh, okay.
I'm just going to do this very high number.
Have a validation that I need to update for
This is checking for numbers.
And then you, you would just do so this would normally would say remaining, but this is your, your variable or the cost of the block.
So it's energy.
Energy charges.
I'm just going to double check that one. These ones, the utility costs I generally have with
I have templates that I created and reused and I haven't actually generated a new one in a very long time. So, um,
Let's just take a quick look.
Yeah, energy charges. I knew it wasn't quite right. Okay.
Yeah.
Energy.
It seems like that answered the question.
Yeah.
Yep.
All right, so we have a couple more models that I want to share. We have the the this geothermal, etc. model.
And I'm actually going to be brave and show this in a dev version because somebody on one of the early days of class asked about something.
And I thought it was a great idea and I started playing around with it. So this is a great, a great model to show it off.
So, um, if you remember yesterday, we had a geothermal system that was connected. It was basically the geothermal loop and it was connected to a heat pump.
And that was it. It was just a single path on the supply side and a single path on the demand side. And there were some questions about, you know, can we do primary secondary loops?
Can we do what about water to water heat pumps? How do we, you know, how would we connect that up to do geothermal loop? So I said, okay, you know, let's just mix it all up into one plant system.
That does a whole bunch of different things.
So, here we have our geothermal loop.
It is
supplying
basically the temperature is follow ground temperature. So it's just, it's just trying to maintain a ground temperature.
Then we have
a little bit out of order, but we have a hot water loop. So this is a fairly normal hot water loop, although I think I've given it an outlet.
Supply temperature of 140 Fahrenheit instead of 180 because that's the heat pump.
And design conditions have been updated for those lower temperatures as well.
Chilled water loop.
And a heat pump loop.
So on the supply side of the heat pump loop is a heat exchanger.
And we looked at a heat exchanger yesterday that was cooling set point control.
This one is dual set point dead band modulated. So it's still using the
heat exchanger outlet node as its set point.
But it's instead of controlling to just a or modulating based on the cooling set point, it's modulating based on a dual set point.
And the set point manager on this loop
is what's called a scheduled dual set point
with a high temperature and a low temperature.
If I have, if I have constant temperature schedules, I like to just name them what the, what that constant number is. I find it much, much easier to manage the model.
And I set two different set points. One is the loop outlet node, which is required because that's what EP3 sets as the set point temperature.
And then the set point temperature for this piece of equipment or the, yeah, the set point node for that particular piece of equipment.
What else?
The loop itself.
We do need an equipment list and an operation scheme.
But because I'm not actually doing anything with the operation scheme, I just have an uncontrolled operations game. So it's, it's not doing anything.
And then, okay, on the demand side.
On the demand side of the heat pump loop.
Okay, so we actually, we still have this heat pump connected directly to the geothermal.
And we have the fan coil connected to the
Tilt water loop and hot water loop.
So
I think I just did one efficiency measure.
There's a lot of stuff going on in one model.
Here's the, here's the fancy trick in the dev version.
Am I getting us?
Most definitely.
Definitely.
I can hear it to the muted mics.
All right. So, yeah, so this is, this is still dev, but it will be out soon.
But we can track temperatures and flows through the, through the entire system.
And it, by default, I may change that default by default, it is tracking all of the temperatures, but you can toggle, toggle on and off, whether to show it or
Yeah, it's whether to show it at all.
And which of the nodes to show them that one's not working now.
That's why it's the
That's why it's a dev version.
Because it's not always working. But yeah, so I think when I was verifying this so we can instead of looking at graphs we can go through and just kind of take a look at what's happening with the temperatures here.
And now we've lost it.
I'm not getting them back, please.
I'm going to turn them off somehow and I'm not getting them back, which is why it's a dev version thing. Okay, so we really wanted to show it.
There we go. Okay, magic combination there.
Okay, so let's take a look. This is in February.
And we start over here.
We can see we have a, and I can't use my mouse to point because when I.
Well, yeah.
Okay, so.
So this will be heating mode. We have a return temperature here of 47 degrees Fahrenheit and a supply temperature of 55. This is a quite small system. We've got 5 GPM really little.
We come around here.
We can see that 55.4 temperature coming through our heat exchanger.
And we are only getting half a gallon a minute here because there's a bunch that's coming out and around to the heat pump the numbers are not activated yet for zone equipment here.
But we have a small flow here.
We have a bit larger flow on this side.
And because we will larger flow, we're not getting quite as high temperature coming out. But that makes sense.
We can see that.
Yeah, 42 degrees. We can tracing that 42 degrees over to our two pumps.
And we do have some flow through both of them.
But there's a bit more on the heating side.
We're in heating mode and then our outlet temperature here is 180.
And maybe did leave that at 180 instead of making it 140.
The temperature is 180.
And that will go into our fan coil units.
Okay, so if we look at a cooling condition.
And that temperature is actually a little bit curious, however.
I'm not quite sure why we're seeing a 30 degrees there. But anyway, okay. So this, this model does show a different all the, all the different configurations with primary secondary.
Loops.
So we have different flow rates between the geothermal system versus the heat exchanger.
The heat pump is still connected to the geothermal system. I was putting this model together last night when I was quite tired.
And part of the reason I put it got that dev version working well enough to show you today was I couldn't for the life of me figure out why the flows over here were were so low.
And it was just that the heat pump was still connected to the geothermal loop instead of the heat pump loop.
Sometimes you just need to, when you're trouble shooting models, you just need to go back and go back to the basics and and look at the diagram instead of looking going into the weeds.
But are there questions on this and we could demonstrate switching that heat pump and connecting it to connecting it to the proper loop.
Yeah.
I'm just having a moment for questions. Yeah.
Thank you very much.
Thank you.
Okay, I'm just
I didn't actually fill in the meter name here, which is which is why
which is why we had a little crash there.
So, and when, when the program doesn't run, you'll just see these three files that RDD will only be there if you have a previous model run that was valid.
Normally, normally, when energy plus simulates it will delete all of your files and then you don't have access to see what sort of output variables, you have so I'd like to leave the RDD for you.
I think there was a question about output variable names, not updating, and we had not been deleting the old files.
So, again, we're simulating energy plus in EP three, we were just replacing the new ones what's the new ones were generated so if you're, if you're simulating it EP three is is currently not that good at telling you whether or not your simulation ran to completion, it will just show you some old files.
And yes, is that if the output meter output variable names are not updating, check your error file, so click on air file button, and it showed it will open the error file in your, your default text editor, and, and just check first of
the error and their fatal errors I'm guessing if the if the meter names are not updating it maybe because you're not actually getting a simulation.
So here, the error that blocked this particular simulation. I remember, I think it was a one or two we were talking about error format and I think this is a good review.
We have the object name.
And then, or I'm sorry, the, there's an object type and name.
And here. So it's something related to utility cost charge block. So we're missing source variable and utility cost Tara.
We're missing a required property output meter. So we have two required properties that we're missing on those.
So here we have our output meter name and the utility cost charge block source variable is
going to be energy charges.
Yeah, energy charges. Okay, so now we can simulate again and actually get some
take a look at some economics.
Okay, so this there's an export errors and warnings. So this is generated by EP three to tell you a little bit about the translation from
EP three to energy plus if you have errors or warnings here it doesn't mean that there's a problem with your energy plus file. It means that there's some things that we weren't able to translate.
Or maybe we chose not to export it because in this example there's a set point manager that's included in the efficiency measure.
It doesn't have any geothermal so geothermal heating. I've unchecked this include in base EM, but geothermal cooling doesn't have any set points on it.
So if you, if you were to have a set point manager in energy plus with no set points, the energy plus simulation would crash, instead of forcing you to delete it or changing this value for you about including it in the
program, we're just going to tell you about it just so you just so you know. So that's what the export errors and warnings are all about.
There yet but in this next step version, you're going to be able to look at any previous.
There's export error reports for so for all of your exports, you will be able to take a look and see what what warnings came up when you exported your file.
And also view your future, or your any import errors from any files that you imported to import errors and then an import report, which would be.
Yeah, so it tells you which files got imported.
And this is a whole bunch of data about that particular import so you get a list, you get a bit of a record of where your thing where your information came from and how things are translated.
Just to reiterate, I got to that by clicking on settings, settings are popping up on my primary screen, which is my other screen settings will always kind of pop up under primary screen.
There's a sometimes if you disconnect a monitor, some of these windows will end up on a wrong monitor.
So if you if you double click any buttons to get a dialogue, if you if you click them once it will turn up where it normally does but if you if you double click it, it will reset itself onto your primary monitor.
So to help you deal with that.
That it that's a general sketch of issue at the sketch of or yeah, we've we've alerted sketch of about it but we've kind of managed it in EP three by allowing you to reset dialogue positions, but some of them.
You don't always have access to this, this button and it may just be stuck off screen with so that those really important ones end up on your primary screen.
As well.
Questions or should we take a look at the solar panels and domestic water model.
No questions came in in the meantime, so we have lots of models to go through so I would say go on to the next one.
Okay.
Solar collectors. Okay.
So, um,
we did look at this one briefly yesterday didn't we but not in a lot of detail.
Here, there are two domestic water loops.
And so one is the domestic water loop and one is the collector loop.
Each one of these is a solar panel.
That is connected to a surface in in the building geometry there each shading surfaces.
The solar panels are on the demand side of the loop because they are.
Uncontrolled equipment they just.
There water comes in at a particular flow and then water goes out and it and it gets heated.
In these systems.
You you probably don't want to have a bypass.
Because a lot of the water may kind of end up flowing around the panels instead of getting forced through the panels.
So on this loop, the.
The flow is going to be kind of forced through these panels.
And then we have.
Two water heaters.
This is the way a domestic water heater kind of normally looks an EP3. And this is a bottle that I imported from the example file. And when I brought it in, this guy was.
Right side up.
Which made these connections really funny. So, um, this is an object where the.
These connections here are normally on the demand side of a loop, but in, in this case.
They're on the supply side and.
Yeah, so it does look a little bit strange, but.
Okay.
Let's start with this water heater a little bit simpler.
So, water heaters can exist in multiple configurations. The sort of the most standard one is.
Well,
we get another model, and I'm loading.
Offscreen.
Okay.
That's half on screen, half off screen. Okay, so a normal.
Normal configuration for a water heater or not normal, but the simplest configuration for a water heater is just to have the water heater and not have it connected to anything.
The water heater.
Has a bunch of different properties that has a volume. It has a set point schedule.
Um, dead man temperature, uh, heater control type. Every water heater kind of has a heater.
By default, it has a tank and a heater. You can essentially turn the, um, the heater off by setting the capacity to, um.
And then the actual internal heater will not turn on, but you can have a electric or gas internal heater for the water heater.
Um,
and then we can set a peak use flow rate, which right now is in meters per second.
And then we can set a peak use flow rate and a flow fraction schedule. So the simplest implementation would just be to say, you know, let's go for five gallons a minute.
And I don't have very many scheduled in this model, but we'll just say five gallons a minute all the time.
And
that would give us our simplest water use. It would be a natural gas water heater with a thermal efficiency of 80%.
The next iteration of a water heater is.
Let's see.
Uh, let's just hide this for a second.
I've just hidden it and energy and sketch up. I'm not actually removing it from energy plus. So.
The next iteration of a water heater would be if it's on a loop.
With a pump and the water heater and then here this object is.
It's called a water use connections.
And so this allows you to define the usage characteristics of your domestic water in a lot more detail.
It has an inlet and an outlet node.
You can you can connect it to a storage tank if you like, but.
You can model grain heat exchangers, but here we go. We have different water use equipment sinks, showers, cold, those washers and dishwashers.
So we go to our all of our objects and we can look at any individual one just by clicking here.
But if we look at water use equipment.
We have clothes washer, dishwasher, showers and sinks. So each one.
We can set a peak flow rate.
We have whoops.
We have a schedule name for the flow rate fraction and for the target temperature.
And then you can also assign it directly to a zone if you want to. So if there was some latent load associated with this particular.
Water use, you could assign it to a zone.
And.
You can set hot water and cold water supply temperatures. So you have a ton of control of your domestic water heating energy use and flow rates.
By default.
In energy plus, if you don't set a.
A cold water supply temperature schedule that the energy plus will model that inlet makeup water because remember, it needs to water loops as a closed loop.
So, in.
Essentially.
What's happening in the simulation as you go through the water heater, you know.
We can start at the water heater. You have hot water at the water heater.
You supply to your water use here in reality, it gets, it gets used. It gets heated, but what energy plus is doing is it's changing.
It's taking a look at the flow rate and it's changing the temperature.
To become the temperature of the ground temperature here. So from here over to here, we have essentially ground.
Temperature water. So that is the, the next iteration.
Of water use equipment in energy plus.
I'm sure there's going to be some questions on this.
Yeah, one question is how do we.
With the water heater that gives off heat as well. How do we assign that to a room? For example, if the water heater is in a room.
Question. Yeah, so this particular model actually doesn't have any rooms. We could add some so we can set it to a room. However.
Here we go. So the water heater. It's this set of inputs.
It's this set of inputs here. So the ambient temperature indicator.
Then you have a choice. You can make it outdoors. You can give it a schedule or you can set it to be a zone.
So if you want to set it to a zone, you click zone here.
And then you would need to select a zone here as well. This, this model doesn't have any zones. It's just modeling.
It's just modeling solar hot water and domestic water.
That's, that's how you would do it. And then you would have, you have your.
Off cycle and on cycle.
Lost coefficient.
And that's B2s per hour per.
Be restarting.
Okay, another question. If the flow through the hot water is higher than the actual demand of the hot water.
Will it model part of the return.
And mix that with groundwater.
So if the flow is higher.
In many, in many circulating systems.
For example, the pump constantly circulates at so many GPM.
So that the water is always hot.
Yep.
And then it's a 10 GPM and you only use 3 GPM.
The return water would be a would be 7 GPM of the warm water.
Minus losses plus the 3 GPM up makeup groundwater.
Yeah, yeah. So I think maybe what we can do is build that system in this, in this other super simple model.
I'm just going to copy and paste my water use.
And then we can add a.
And.
This will be like a.
60 degree.
And it's going to give us a boiler that we then do. Okay, so.
That bypass.
It's so in this configuration.
We have all the water going through the water heater.
We could actually keep that bypass for.
Be careful with with undo. Sometimes you have to redo your connections.
When you're going to do something.
Yeah, this would actually potentially.
Look a bit like.
System that had had recirculation, I would probably honestly, probably.
If you wanted to truly model recirculation, I might do a primary secondary loop situation.
But here.
We could bypass water around the water heater.
And then if there's not that much flow here, it would bypass around that water use equipment as well. So yeah, you could, you could absolutely do that configuration and this is how I would set it up.
Makes sense to me.
Okay.
Solar collectors.
Right. I have some shortcut keys set up to hide and unhide things in Sketchup.
If you want to set up some hotkeys, you can go to windows and preferences.
And go to shortcuts. And there's a ton of options for.
Different things that you can do with shortcut keys tools that you can select.
Yeah.
View modes like.
One that I find is really quite useful is.
Camera interviews top have shift T assigned as a shortcut. So if I'm in my model and I get a bit confused about where I am in space, I can just hit shift T and I will.
Get back to the top.
So there we go.
That's the.
Anyway, just, just things to help you with your workflow. Okay, so we have our.
More complex system now.
Actually, the next iteration of complexity here.
Let's do one more iteration of complexity where we.
Say hot water loop.
And this time we're going to keep the boiler.
And I can connect the.
So now, now we have a water heater.
That has.
That can be heated by a hot water system.
Be a little bit careful with this because by default, especially coming from the wizard, the water heater is coming in at the moment with.
The natural gas.
So you'd want to go in and change the capacity here to zero. So essentially turn off the internal heater and only allow passive heating.
Not sure why it's set up this way and energy plus it just, it just is it doesn't really make sense to my mind.
Because it should be, you know, maybe one or the other, or that, you know, every, every other place in energy class, they have a million different objects and, and I'm not sure why this one is set up this way, but, but it is, and it's all right.
So here we have the, the.
Or we have the, we have a heat exchanger hot water heat exchanger heating the tank.
So that's kind of what's drawn here. So that's next level capacity.
So in the solar water example.
We are using the output from the solar panels.
So these two nodes here, these two connections.
Those are the same ones that are connected to.
The hot water system here.
So this is what's providing heat, the water heater.
And.
With the solar heating system.
That's what's providing heat to this tank. So this tank is basically the only active component here really is pump.
Let's take a look at what the operation scheme is for this model.
So it is giving the.
It is calling on this storage tank as.
Equipment in this, in this model, even though it can't really provide a load.
Every time I look at this model, I find more and more things fascinating. Okay. So essentially.
We have a tank here with it's 396 almost 400 gallons.
It's getting heated passively by the solar collectors.
And then on this side.
The this tank could go to quite a high temperature that could go up to 180.
This one.
Okay, so we've got a step point manager here.
And we are setting a temperature of, okay, so we're going up to.
The, the, this model is not set up great. It should be.
This is a schedule that's in Celsius.
Even though we are otherwise looking in IP units, be careful about that. If you're looking at example files and importing files is that the.
They've selected in any number type schedule.
And so there is no information connected to that schedule that allows us to do the units conversion.
So you have no information that lets you do the units conversion so it won't be able to convert it. So just, just be careful.
If you see a schedule that's come in from an example file or an existing model.
And the units don't look right in the schedule. Just check the schedule type limits.
Okay, so the.
If the temperature here is too low.
Because the passively heated storage tank is not hot enough.
This tank right here, which is it's only a gallon and a half. It's essentially.
It's an instantaneous water heater.
It's basically a little electric resistance coil and will heat the water up the up to the remaining amount.
And this is a tempering valve.
Also, it is.
Taking water from the.
Essentially from the bypass, so it's taking return water here.
And.
So, yeah, so it can it's sort of controlling the flows between this stream, which is heated and the stream, which is.
Just coming from the return. So this is essentially ground water and it's going to mix them.
To make this temperature here to maintain a low enough temperature. So if temperature coming in.
If the temperature coming through the heat exchanger is too high, it will mix in some water from this side.
In order to maintain the correct temperature.
Okay, so let's see you've got.
Some results here.
Actually, I think the temperatures.
Here.
And.
I might.
reopen this file and another instance and see if we can use the.
Fancy new version.
Thank you.
No, it's not going to let us do it. I was going to give it a shot in the, in the new version so we could actually see the temperatures.
I just have it loaded for the other file.
But okay, so let's let's just track some temperatures on around here.
So I'm not giving us our labels either.
Okay, I apologize that that is that one is not giving us the labels that I'd like to show, but we just have a couple, a couple minutes left. So let's let's open it up to questions.
And yeah, let's see what questions comments.
We've covered a lot in this period of time. I'm quite tired.
And yeah, so.
Thank you here. In the meantime, I was going to say that there's been some requests in the questions and chat.
For items in the forum and I wrote those down. You are sharing these files. It sounds like.
In the forum.
Yeah, I will send an email when I get them shared, but yeah, they will all be shared for you. And there were two other items I had on the list.
There was a desiccant wheel and there was a radiant system where I can, I can show that how the radiant system is set up, but it's not quite live.
Like I said today is today is a bit about starting to explore.
It's a bit less exactly how to do things. But it's, I hope.
I hope the takeaway is how to find the information, explore your models and develop your systems and where to find all of that information.
And, and really how to understand what you're doing. It's not, not just giving you a couple of, of pre baked ingredients that you can only combine in three different ways.
There's a lot of information you can combine it a lot of different ways. And let me know if there's a specific system that you were really hoping to learn about that you don't learn about and I can get you some example files.