Single Stage Heat/Dual Stage Cool
Hi! Just a quick question. Two years ago I had a single stage/multiple speed 80% furnace installed (Coleman G8C). I am thinking of upgrading the cooling this year. Is it possible to get a 2 stage cooling system to work with this furnace? I know I would at least have to get a 2 stage thermostat. I thought maybe there was a way since the furnace has multiple speeds. Thanks!
If by saying multi-speed you mean variable speed, then you should be able to do it. I have a feeling you don't have a variable speed due to it being a single stage furnace. I'm not familiar with Coleman, so who knows for sure.
I like DIY'ers. They pay better to fix.
The "multi-speed" refers to the air handler fan motor.
Originally Posted by jclaar
You can get a 2-stage condenser and a matching indoor coil, but you really need a variable speed air handler motor to get the best efficiency out of that 2-stage condenser. If you don't have a v-s motor, I wouldn't go any higher than a 14 SEER system because you won't obtain the higher SEER rating without a v-s motor.
Okay. Thanks for the fast replies!
if you wanted to use a 2 stage unit adding a relay to control fan speed would be easy to do.
would not get the rating of a v drive blower but it would work.
can't go into details but contractor should know how to do it.
we had 2 stage units a long time before we had v drive blowers.
Great! I thought I read somewhere else about relays. Thanks again. Also, are the media filters worth the extra money? (hijacking my own thread!)
Yes they are, if the duct work is sized right.
Your multispeed won't slow down enough to take full advantage of 2 stage cooling.
It won't have the full ability to remove humidity in first stage cooling.
You can either have a fan speed control installed, or a VS motor upgrade installed.