Ah, Cool Air!

We finally replaced our old, shoddy air conditioner which never really could cool the house. I'd been monitoring vendors and prices for several years, but hadn't come across a good combination. That is until one of Connie's co-workers recommended a guy name John Christian at Nova Heating & Air. I had always felt that a large part of our problem was the poor ductwork in the attic. Only one guy I had previously talked to had addressed this issue in his quote, but he was way expensive. Most guys would just focus on the air conditioner side (it was a known fact that our old 4 ton unit was undersized). But John immediately said that all of the ductwork had to be replaced, and that our returns were grossly undersized. Since his price was reasonable and we qualified for the Federal Tax Credit, we decided to go for it. We'll also get some payback on our electrical bills with the increased efficiency as the new unit is rated at 16 SEER while our old system was only 10 SEER.

This is the outside heat pump (it's a Carrier 5-ton unit with a 2-stage compressor). It is so much quieter than the old unit. The fan coil (with variable speed drive) is located in the attic space.



Our return duct was undersized so we added a second return in the hallway.


This is the new thermostat. What's the big deal about a thermostat? I wouldn't think too much, but this is our 3rd one. John initially installed one of Carrier's high-end thermostats, but it just did not control the temperatures properly. We would have wide (up to 5 deg) swings in temperature no matter how we set it up. John thought that maybe it was defective so he installed another one. Same problem. So this time he switched to a different thermostat made by Source1. This did the trick as the temps are now tightly controlled.


A cool feature with this thermostat is that it works with wireless sensors. That makes it really easy to experiment with different locations until you find good spots to sense temperatures. You can have the thermostat control to its internal sensor or average multiple sensors. I have a second inside sensor that monitors the first floor temp.

This is a temporary location for the outside sensor. Being able to sense outside air temp opens up more control possibilities...


We're thinking about adding on a feature called "Free Cooling". Now of course nothing is free, but by knowing the outside air temp and adding an outside air supply to the fan coil, we can program the thermostat to use outside air instead of the heat pump when the outside temp is cool enough. Since this house retains heat well into the evening, this should save a lot of energy by not running the heat pump when we don't have to. We could (should) just open up the house in those situations, but more often than not, we forget about that and you hear the AC running at the strangest times. With the Free Cooling mode, it will "open" the house for us automatically, and allow us to be lazy bums :^)