Excellent system with very good performance/efficiency numbers. I would suggest the 824 thermostat on dealer's dime. What are you doing about return air filtration?...if you don't already have one, I would suggest Trane's Perfect Fit media cabinet. Pricing reasonable, nothing special.

IMO

7039031 ActiveSystems TRANE XR17 TRANE 4TWR7036B1 b*AM7A0C36H31 1225 980 36000 13.00 17.00 34000 9.00 21200 1 HRCU-A-CB Yes 269 768 Yes

Thank you for the response. I asked for an updated estimate with the XL824 Thermostat and indoor / outdoor sensors also about switching to 8kw heat strip. as far as the filtering my old Trane used disposable 20 x 20 x 1" filters. Don't the new Air Handlers (variable speed) have the same kind of set-up? Or are you recommending a better filter choice?

for your Southern location, I see no reason to waste your money on outdoor sensor. Why? Because it will be rare when you need backup heat. Let the thermostat control that decision. I am recommending Trane's Perfect Fit Media cabinet that would be installed on return end of air handler. Changeout is easy if reasonably accessible, filtration is much better as far as indoor air quality along with protection of evap coil and blower motor, and these filters last up to one year before they need replacing. How many returns do you have in your present ductwork system?

Why do you want to move up from a 5 KW to 8 KW heat strip?

IMO

On the 8kW heater....My old system had the 5kW heat strip and there were a few cool / cold days it had trouble keeping the heat up. I thought the senors were needed for the thermostat to operate most efficiently It looks like 4 returns to the main return plenum alongside the air handler.

I would definitely get the filter media cabinet I suggested...still don't understand the need to go up to 8 KW...you get 21 K BTUs off the condenser at 17 deg fah...add in the 5 KW gives you 17 K additional BTUs...but your decision..

IMO

OK thanks again. Maybe with the variable speed air handler, it wont cool the air into house as much as a single speed on / off fan does and 5kW will be enough

VS air handler has nothing to do with heating comfort or BTUs...

IMO

Not that BTU's would be any different, just thought that the variable handler fan gradually coming on and ramping up to speed instead of full on blast would make air "feel" warmer. Also updated estimate now with XL 824 thermostat and electrostatic filter at $7200 total. Kind of surprised there so much "play" in price. This company started at $7900 with Xl624 thermostat and no electrostatic filter. Thanks for your input as you see its helped me a bit already.

One of the competing dealers wants to switch the air handler from TAM7 to a TEM6 unit saying Trane is having problems with the TAM7. I see the TEM6 is much less (feature-wise). I'm aware the TAM7 is supposed to leak a bit of air from the front cabinet door. Since this is going in the garage, I was told this is actually preferable to the "blower on top" creating negative pressure and pulling garage fumes thru-out the house. Also could this be simply solved (although not pretty) by duct tape if air leakage appears excessive?

I se nothing wrong with either air handler. If you are speaking of Clean Effects electronic air filter or a third party similar model, I am opposed to them. They can be problematic especially due to routine PM/maintenance that homeowners simply will not do. I favor pleated filter media cabinet like Trane's Perfect Fit. No maintenance at all. I am a proponent of the KISS principle.

IMO