View Full Version : Heat and Cold Air Returns on Top
CarrieandRay
Jan 29, 2009, 12:37 PM
Is there any reason the building we bought would have both heat vents and cold air returns near the ceiling?
Would it help on the heat bill if we would move the heat vent more towards the floor?
Thanks for your input.
hvac1000
Jan 29, 2009, 12:55 PM
What kind of building is it? Is it a commercial structure or a home?
CarrieandRay
Jan 29, 2009, 01:38 PM
It's 4,000 sq ft of retail space with just one cold air return but several heat vents up high.
Our tenant says her heating bill can be as high as $1800 per month, so we're trying to figure out what can be done to lower it.
hvac1000
Jan 29, 2009, 02:26 PM
Usually commercial structures have both supply and return air ducts in the ceiling. The reason for this is because many times the units are located on the roofs and it is not smart to locate supplys or return air openings at floor level since the display areas might change many times with many different tennents and they could be blocked. I have no idea where you are located by 1800.00 is not to bad for 4000 sq ft retail. Door opening and closing,lighting loads all take a toll on the utility bill.
CarrieandRay
Jan 29, 2009, 09:27 PM
Thanks for your insight.
Our tenant keeps half of her store blocked off to keep things warmer up front, but it has been a cold Wisconsin winter.
KISS
Jan 29, 2009, 09:43 PM
It's kind of rough to design for commercial spaces. Look at thermostat location and the number of fan coils and/or thermostats. Make sure the thermostat is in the correct place.
When hallways are involved the returns are usually placed in the hall. One return just doesn't sound right.
Thae entryway can easily take a toll on the heating bill. Air curtains and double doors help revent infiltration of air.
I think the only real way to figure out what's going on is:
1. Do an energy audit with an infared camera
2. Seal any leaks
3. Handle the entrance differently
4. Use suspended ceilngs
5. Use celing fans if needed
6. Do a manual J (size system)
7. Know exactly what you have and how efficient it is
8. Zone it
MarkwithaK
Jan 29, 2009, 09:46 PM
One return is the norm on commercial buildings that have the equipment located on the roof.
CarrieandRay
Jan 30, 2009, 09:29 AM
Thanks for your help, everybody.
hvac1000
Jan 30, 2009, 10:07 AM
Your welcome