Hello,
I?m having some trouble with my simulation ? I?m currently working on this
for a LEED project and I?m putting the proposed design together. I think
I?m at the point where I?m about finished with the proposed design. When I
run the simulation, it is showing almost as much electric used for heating
as I?m using for cooling ? the problem is that nearly the entire building
uses gas heat. Can someone help me out here?
Thanks
*Mike Campbell, EIT, LEED AP O+M
Just looking at your INP file quickly, it appears you have several electric
unit heaters that are trying to keep spaces heated to the same 72 degree
temperature as the rest of the building. You may want to put those spaces
on a separate schedule with a lower thermostat setting as they are
unoccupied and not necessary to keep at high temperatures unless desired by
owner. Those systems should also be taken off of any fan schedule so they
only turn on when necessary to reach space setpoints. if you eliminate the
schedule, make sure to turn on the option of night cycling without OA.
Hope this helps,
Rob
I just experimented by changing my heating setpoints from 72 to 55 in the
areas with unit heaters, and it had no effect at all on the electricity
usage for space heating. How can this be?
*Mike Campbell, EIT, LEED AP O+M
*From:* Rob Hudson [mailto:rdh4176 at gmail.com]
*Sent:* Monday, August 27, 2012 4:42 PM
*To:* Michael Campbell
*Cc:* equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] Help - excessive electricity for space heating
Just looking at your INP file quickly, it appears you have several electric
unit heaters that are trying to keep spaces heated to the same 72 degree
temperature as the rest of the building. You may want to put those spaces
on a separate schedule with a lower thermostat setting as they are
unoccupied and not necessary to keep at high temperatures unless desired by
owner. Those systems should also be taken off of any fan schedule so they
only turn on when necessary to reach space setpoints. if you eliminate the
schedule, make sure to turn on the option of night cycling without OA.
Hope this helps,
Rob
Looks like several PSZ heat pumps with "Heating-EIR" values and some other unit heaters using electricity.
David
David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
When I make changes to the system operation it doesn?t have any effect on
the overall heating electricity. For example, I tried eliminating the unit
heaters in the garage and changing set points in the other spaces, but it
had no effect at all on the total electric for space heating.
*Mike Campbell, EIT, LEED AP O+M
*From:* David Eldridge [mailto:DEldridge at grummanbutkus.com]
*Sent:* Monday, August 27, 2012 4:56 PM
*To:* 'Michael Campbell'; equest-users at lists.onebuilding.org
*Subject:* RE: [Equest-users] Help - excessive electricity for space heating
Looks like several PSZ heat pumps with ?Heating-EIR? values and some other
unit heaters using electricity.
David
*
*
David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
*
*
*From:* equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Michael
Campbell
*Sent:* Monday, August 27, 2012 3:26 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] Help - excessive electricity for space heating
Hello,
I?m having some trouble with my simulation ? I?m currently working on this
for a LEED project and I?m putting the proposed design together. I think
I?m at the point where I?m about finished with the proposed design. When I
run the simulation, it is showing almost as much electric used for heating
as I?m using for cooling ? the problem is that nearly the entire building
uses gas heat. Can someone help me out here?
Thanks
*Mike Campbell, EIT, LEED AP O+M
I just ran your files, and in the BEPS report, I show 9,284 MBTU gas
heating and 490 MBTU cooling. Regardless of what's happening with your
electric heating, something doesn't seem right there unless you are
modeling a building in Antarctica.
I'd look at all of the funky exhaust flow rates you have for your zones.
EL1 NE Perim Zn (G.NE9) under the UH Electrical system has a supply flow
rate of 5 CFM and an exhaust flow rate of 1,200 CFM with infiltration
makeup. So if that zone heating temp is not met, it's trying to heat
the space with 5 CFM of supply air yet there is then a simultaneous
1,200 CFM infiltration load ??
I don't know, maybe you've got it set up correctly, I just never use
plenums or zonal exhaust because I think it unnecessarily complicates
things. Then again, I normally model office buildings.
James Hansen, P.E., LEED AP
If I don?t model the zonal exhaust, how else can I model this?
*Mike Campbell, EIT, LEED AP O+M
*From:* James Hansen [mailto:JHANSEN at ghtltd.com]
*Sent:* Monday, August 27, 2012 5:09 PM
*To:* Michael Campbell; David Eldridge; equest-users at lists.onebuilding.org
*Subject:* RE: [Equest-users] Help - excessive electricity for space heating
I just ran your files, and in the BEPS report, I show 9,284 MBTU gas
heating and 490 MBTU cooling. Regardless of what's happening with your
electric heating, something doesn't seem right there unless you are
modeling a building in Antarctica.
I'd look at all of the funky exhaust flow rates you have for your zones.
EL1 NE Perim Zn (G.NE9) under the UH Electrical system has a supply flow
rate of 5 CFM and an exhaust flow rate of 1,200 CFM with infiltration
makeup. So if that zone heating temp is not met, it's trying to heat the
space with 5 CFM of supply air yet there is then a simultaneous 1,200 CFM
infiltration load ??
I don't know, maybe you've got it set up correctly, I just never use
plenums or zonal exhaust because I think it unnecessarily complicates
things. Then again, I normally model office buildings.
**James Hansen, P.E., LEED AP*
*From:* equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Michael
Campbell
*Sent:* Monday, August 27, 2012 5:00 PM
*To:* David Eldridge; equest-users at lists.onebuilding.org
*Subject:* Re: [Equest-users] Help - excessive electricity for space heating
When I make changes to the system operation it doesn?t have any effect on
the overall heating electricity. For example, I tried eliminating the unit
heaters in the garage and changing set points in the other spaces, but it
had no effect at all on the total electric for space heating.
*Mike Campbell, EIT, LEED AP O+M
*From:* David Eldridge [mailto:DEldridge at grummanbutkus.com]
*Sent:* Monday, August 27, 2012 4:56 PM
*To:* 'Michael Campbell'; equest-users at lists.onebuilding.org
*Subject:* RE: [Equest-users] Help - excessive electricity for space heating
Looks like several PSZ heat pumps with ?Heating-EIR? values and some other
unit heaters using electricity.
David
*
*
David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
*
*
*From:* equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Michael
Campbell
*Sent:* Monday, August 27, 2012 3:26 PM
*To:* equest-users at lists.onebuilding.org
*Subject:* [Equest-users] Help - excessive electricity for space heating
Hello,
I?m having some trouble with my simulation ? I?m currently working on this
for a LEED project and I?m putting the proposed design together. I think
I?m at the point where I?m about finished with the proposed design. When I
run the simulation, it is showing almost as much electric used for heating
as I?m using for cooling ? the problem is that nearly the entire building
uses gas heat. Can someone help me out here?
Thanks
*Mike Campbell, EIT, LEED AP O+M