Dual Thermostat - Whats needed?

Dallas · 01-03-2008, 02:23 PM

I did a search and found nothing close. Perhaps its because I am not sure what it is called.

I have a two story house that has one thermostat upstairs. When the heater is on the thermostat reads the temperature upstairs, and since hot air rises, it is much warmer upstairs while its really cold downstairs.

I would like to explore having a thermostat for the downstairs as well. Does the actual HVAC need to be a certain dual-compatible unit? What options do I have to have a thermostat for each floor? I am thinking that there needs to be two units, one per floor.

I have been closing the 5 upstairs vents until its bed time and would like something that requires something less of a hassle.

jerryh3 · 01-03-2008, 03:11 PM

A thermostat on each floor will do no good unless you have two seperate heat units installed. I think some systems can have motorized dampers to compensate for different zones, but unless the system is set up for it now, there's nothing you can do besides what you're doing now with the vents.

BarryKaraoke · 01-03-2008, 03:16 PM

The larger problem with your plan is that since both thermostats end up heating the entire house you will just be switching problem floors. In order to heat the lower floor to a comfortable level you will bake the upper floor. If you want to do this you don't really need a second thermostat, you just need to move the one you have. Adding a second is just a waste of money because the upper floor will always be hotter than the lower floor so the upper thermostat will never call for heat.

The real answer is a zoned system that only heats one floor at a time...but that's means a lot more than just another thermostat...

bigMikeB · 01-03-2008, 06:50 PM

Yup you need zoning.
Another victim of builders special hvac.

biggles · 01-04-2008, 12:09 AM

depending where the furnace is up or down stairs,if you zoned the 2nd floor with damper on the supply to that floor with a mod motor an simple stat.then take the actual unit stat and relocate it near the return vent for the 1st floor.that done you set the 2nd floor to say 65F + the heat rise up the stairs and downstairs to 70F...when the 2nd hits 65 the damper will modulate to close the supply going upstairs,you will increase the air to the 1st floor and adjust that stat a little down so it is comfortable and the unit cycles off.the upstairs will be totally indepemdent of the heating system and even open up if the rooms drop below setpoint with the 1st floor setting not far behing to bring the unit on.

01-03-2008, 02:23 PM	#1
Dallas Newbie Join Date: Oct 2007 Posts: 24	Dual Thermostat - Whats needed? I did a search and found nothing close. Perhaps its because I am not sure what it is called. I have a two story house that has one thermostat upstairs. When the heater is on the thermostat reads the temperature upstairs, and since hot air rises, it is much warmer upstairs while its really cold downstairs. I would like to explore having a thermostat for the downstairs as well. Does the actual HVAC need to be a certain dual-compatible unit? What options do I have to have a thermostat for each floor? I am thinking that there needs to be two units, one per floor. I have been closing the 5 upstairs vents until its bed time and would like something that requires something less of a hassle. Last edited by Dallas; 01-03-2008 at 02:31 PM.

01-03-2008, 03:11 PM	#2
jerryh3 Member Join Date: Dec 2007 Location: Baltimore, MD Posts: 1,802	Dual Thermostat - Whats needed? A thermostat on each floor will do no good unless you have two seperate heat units installed. I think some systems can have motorized dampers to compensate for different zones, but unless the system is set up for it now, there's nothing you can do besides what you're doing now with the vents. Last edited by jerryh3; 01-03-2008 at 03:14 PM.

01-03-2008, 03:16 PM	#3
BarryKaraoke Newbie Join Date: Jan 2008 Posts: 8	Dual Thermostat - Whats needed? The larger problem with your plan is that since both thermostats end up heating the entire house you will just be switching problem floors. In order to heat the lower floor to a comfortable level you will bake the upper floor. If you want to do this you don't really need a second thermostat, you just need to move the one you have. Adding a second is just a waste of money because the upper floor will always be hotter than the lower floor so the upper thermostat will never call for heat. The real answer is a zoned system that only heats one floor at a time...but that's means a lot more than just another thermostat...

01-03-2008, 06:50 PM	#4
bigMikeB Union HVAC Tech. Join Date: May 2007 Location: New Jersey Posts: 607	Dual Thermostat - Whats needed? Yup you need *zoning.* *Another victim of builders special hvac.*

01-04-2008, 12:09 AM	#5
biggles Member Join Date: Jan 2008 Location: Long Island Posts: 3,247	Dual Thermostat - Whats needed? depending where the furnace is up or down stairs,if you zoned the 2nd floor with damper on the supply to that floor with a mod motor an simple stat.then take the actual unit stat and relocate it near the return vent for the 1st floor.that done you set the 2nd floor to say 65F + the heat rise up the stairs and downstairs to 70F...when the 2nd hits 65 the damper will modulate to close the supply going upstairs,you will increase the air to the 1st floor and adjust that stat a little down so it is comfortable and the unit cycles off.the upstairs will be totally indepemdent of the heating system and even open up if the rooms drop below setpoint with the 1st floor setting not far behing to bring the unit on.

Dual Thermostat - Whats needed?