Questions for choosing HVAC plants and Fan capacity.

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Hi, everyone: This is my first baseline model, and this simple model is only purpose for my training . The building is a 6 floors office, and the HVAC system is VAV with PFP box as the baseline required. After I completed the Building Shell & Internal Loads steps, I made a run and got the Space Peak Loads Summary like the illustration below. I want use them to choosing the reference plants Capacities ,the Space Flow Rate and the Fan power. And there is 3 questions: 1. You can see there is a Space named "Plum", the unconditioned space above the ceiling. Should we calculate the plum loads when we choose the VAV system and Fan plants? Should we direct use the building peak load for choosing the chiller's capacity? 2. ASHRAE 90.1 appendix G 3.1.2.2 said that the Equipment Capacities should be oversized 1.15 for cooling and 1.25 for heating. Is this suggestion suit the calculation way which I used? My friend told me he always choose 70% of the peak loads for the plant capacity(but he use TRANSYS, not eQUEST), is that a good method ? 3. Using the appendix G 3.1.2.9 method , we could calculate the P-fan( watts ). But I found I could only input "in. WG" & CFM in eQUEST, there is no way to input the P-fan. It's really puzzled me. By the way , is there any simple method for make a baseline? We need to simulation 4 directions ,and if there is a lot of spaces in the model , it should be really a great amount of work to do(like specify the air flow rate of every space's parallel fan). That's all. thank you very much, any tips should be appreciate. Best wishes. Joey ------------------------------------------------------------------------ --- Joey Jiao Graduate Engineer
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Hi, Cordialmente:

I can find the unoccupied temps in 6.4.3.3.2, like below:

The minimum design flow should be 2.15L/s*m2 for VAV system 5 & 7. In G3.1.3.1.3

It??s weird I can??t find the other temps too, sorry.

I get the other temps form our country??s local code.

I will try to find the others too, if I get it , I will give you a message as soon as possible.

Best wishes

Joey.

??????: Andres Franco Usme MicroCAD S.A.S [mailto:andres.franco at microcad.com.co]
????????: 2011??10??10?? 7:39
??????: Jiao, Joey
????: RE: [Equest-users] Questions for choosing HVAC plants and Fan capacity.

Hi Joey, According ASHRAE where are you found the design temps? What design temps are you using?, I??m trying to create a baseline model and I don??t find those data, by default you find this (See image below), but I think that??s so generic, if you can bring me some help I??ll so grateful, thanks in advance.

Cordialmente,

Andr??s Franco U.

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This will be helpful too.

??????: Andres Franco Usme MicroCAD S.A.S [mailto:andres.franco at microcad.com.co]
????????: 2011??10??10?? 7:39
??????: Jiao, Joey
????: RE: [Equest-users] Questions for choosing HVAC plants and Fan capacity.

Hi Joey, According ASHRAE where are you found the design temps? What design temps are you using?, I??m trying to create a baseline model and I don??t find those data, by default you find this (See image below), but I think that??s so generic, if you can bring me some help I??ll so grateful, thanks in advance.

Cordialmente,

Andr??s Franco U.

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Hi, Cordialmente:

I have asked some experienced friend.

He said the design temp should be found from the different local code. You can asked the HVAC engineer, they will familiar with that. I have found the reference information from the local code of the building site.

I try to find out answer form ASHRAE but failed this morning. I want know how should US. Engineers get information when they meet the problem.

Hope this is helpful.

Joey

??????: Andres Franco Usme MicroCAD S.A.S [mailto:andres.franco at microcad.com.co]
????????: 2011??10??10?? 7:39
??????: Jiao, Joey
????: RE: [Equest-users] Questions for choosing HVAC plants and Fan capacity.

Hi Joey, According ASHRAE where are you found the design temps? What design temps are you using?, I??m trying to create a baseline model and I don??t find those data, by default you find this (See image below), but I think that??s so generic, if you can bring me some help I??ll so grateful, thanks in advance.

Cordialmente,

Andr??s Franco U.

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Joined: 2011-09-30
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