Last week we replaced our 23 year old carrier furnace (125K BTU input ~65% efficiency) and 16 year old 2.5 ton Kenmore A/C with the following in our 3400 sq ft house (main level and basement):
1) TUD100R9V3K - Trane 80% 2 stage furnace (variable speed)
2) 4TWX6036B100A - Trane XL16i Heat Pump (w/RXC036S3HPD coil)
3) TCONT803 - Trane Thermostat
4) Aprilaire M-700 Poweer Humidifier
5) Aprilaire 2200 - Media Filter
I really wish I had found this site prior to making our decision on equipment and install. We didn't get a formal load calculation but I did get several quotes and hope I picked an appropriately sized system (furnace may be a bit oversized) and reputable installer. I'm a bit worried about our install, especially the heat pump, controls, and making sure we get the full capability out of a system that was pretty expensive. In retrospect, I don't think my installer had much experience with this specific setup. He was not in favor of the Trane Fossil Fuel Kit and thought he had previously used 2 outdoor thermostats to control the heat pump and gas furnace.
I really want to get full use out of at least the most important capabilities of this new system. Any thougths on the following would be greatly appreciated:
1) Can the TCONT803 really provide good/reasonable control of this system and capabilities?
2) The TCONT803 allows me to set a balance point for using the heat pump versus gas furnace. We've initially set it to 40 degrees but the T-stat only allows 7 settings (15,20,25,30,35,40,45 degrees). Is not being able to set this more finely a real problem?
3) The oudoor temp sensor used for determining when to use heat pump/gas furnace seems to be a problem. It is sometimes in direct sunlight and close to brick exterior which also affects temp accuracy (higher and lower at times). Is there a typically good place to locate this sensor? Can/should it be located inside heat pump panel? Or is just out of any sun OK?
4) How does the TCONT803 control the 2 stage gas furnace? Does it just run the 1st stage for 10 minutes and then kick to 2nd stage? Is this a significant limitation?
Any thoughts on my current system/install and if I need to change any setup would be much appreciated. Thanks in advance.