Hi,
I am currently using eQUEST to simulate the performance of a building (an
ideal case), where in the HVAC operates at the below temperatures 24x7 for
the whole year.
Below are the preset values:
Heat when temp <= 74F Cool when temp >= 76F
Ideal temp of the building is 75F
Also cool, when the outside temp >=72F
Error in Simulation:
I always see that the total heating power consumed in Jan/Dec month
(Winter) is lesser than that July and August Month (Summers).
But the simulation's outside Dry Bulb Temperature (avg, min and max
Temperature) is higher during July/August when compared to Jan/Dec month.
If I operate the HVAC for 12x7 (7am to 7pm) for all the days, then it
follows the seasonal pattern (heating power is higher in Jan/Dec than
Jul/Aug).
But I need to get the power O/P when it operates for 24x7 only!
Please let me know as to why this error introduced, and how to rectify it!
Or must I add some more details in the detailed edit.
Regards,
Siddharth Venkatraraman
Depends on what kind of system you are using. looks like there is some
kind of reheat going on in the night hours during summer.
-rohini
To follow up on Rohini's comments:
If your lights and equipment are on the 12/7 schedule, and you have a constant volume reheat then your supply volume is probably based on the peak condition, and anything below is reheat. Did your cooling load also go down drastically when you switched to 12/7 mode?
Could you attach an inp file?
Vikram Sami, LEED AP
Hi Vikram and Rohini,
Thanks for the response.
Well, I see that on July/August, the Humidity levels are pretty high. So
in order to remove excess humidity in the air, the heater operates.
So that satisfies the heating energy levels.
But actually I am trying to find a correlation b/w the HVAC Power
consumption and Heat Index(Dry Bulb + Humidity) per month.
For statistical purposes, am finding the correlation between the Power
consumed and difference b/w the actual and the expected.
For eg. If my room temp is 72F, and outside the Heat Index is 90F,
Difference is 18F. Power Consumed is P1
If the outside temperature is 54F,
Difference is again 18F. Power consumed is P2.
And there is a huge difference, as P1> P2. Always. Anything to be altered
in the Heater Side of HVAC.
And also please let me know on how to nullify the humidity control of HVAC
in eQUEST! The wizards do not have an option. And am unable to find it in
the Detailed Edit.
Am unable to attach the project file,as it is approximately 18Mb. I will
upload it in a common area and will update you with the link!
Regards,
From: To:, Siddharth V Cc: Date:
"Sami, Vikram"
R B
equest-users
06/29/10 06:58 PM
Subject:
RE: [Equest-users] HVAC simulation
To follow up on Rohini's comments:
If your lights and equipment are on the 12/7 schedule, and you have a
constant volume reheat then your supply volume is probably based on the
peak condition, and anything below is reheat. Did your cooling load also
go down drastically when you switched to 12/7 mode?
Could you attach an inp file?
Vikram Sami, LEED AP