What you seem to be looking at is a gas-combo boiler system to provide in-floor radiant heat and instantaneous domestic hot water, an air-source heat pump for forced air air-conditioning and a solar rooftop PV system if youâÂÂre considering something like the Lennox set-up. ThatâÂÂs 3-discrete systems to install and maintain.

As an alternative, depending on energy prices and you would have to crunch your own numbers, you could install 1-triple function geothermal heat pump that will integrate ALL the heating and cooling functions into 1-machine operating at high efficiency.

This is just a suggestion of what is technically possible.

As example see link below.

SR

Here is a link that might be useful: Geothermal Triple Function Heat Pump

Thanks SR, that was extremely helpful
We now think we are going to go with the Lenox XP 21 and install the solar panel with that. No radiant heat.

I would suggest that rather than the Lennox XP 21 that you look at the Carrier Infinity Greenspeed heat pump or air-conditioner. Rather than being 2-speed as the Lennox HP is, which is very good, the Greenspeed is inverter controlled and fully variable between 40% to 100% output. Additionally, the Carrier Infinity Greenspeed system with their new Infinity WiFi communicating/learning/smart recovery thermostat is presently the most advanced residential air-source system available with an âÂÂup toâ 20 SEER, 13 HSPF for the HP and âÂÂup toâ 21 SEER for the air-conditioner.

Lennox by contrast, in my opinion, is on the cusp of selling snake oil with regard to their âÂÂSunSourceâ Home Energy System. They âÂÂseemâ to be giving the impression that this solar system can run their heat pump. I have my doubts; if you would want to start a heat pump âÂÂoff-gridâ a 20kW backup generator would be needed. An equivalent solar array with accompanying inverter/battery compliment that can cope with the massive in-rush of current necessary to start a compressor would by its very nature have to be quite massive and expensive. Should I be missing something here, please someone inform me!

Having read through the Lennox SunSource literature, it seems to me that this is more than anything an opportunity for the Lennox corporation to take advantage of the American tax payer through the âÂÂU.S. Emergency Economic Stabilization Act of 2008â to provide up to a 30% tax credit and âÂÂup toâ a $1500 tax credit. If these systems were that great no subsides would be required.

As always - Caveat Emptor!

IMO

SR

Here is a link that might be useful: Carrier Infinity GreenSpeed Series

SR
Thanks again for the information. Really have no idea which way to go. Would just like to put in the most effective system that would provide our heating and cooling at the most resonable cost.

How much do you pay per kW of electricity, gas?

How much heating do you expect to do?

Do you plan to install NG?

SR

Electric kwh 11.8 kwh (Horry Electric Cooperative, Inc.
Natural Gas $1.09209 per therm (South Carolina Electric and Gas)
Yes we will have natural gas installed. There is 1,550 sq ft of living space. Plus a pool to heat and cool (23'x11'6" - 3.4-5ft deep)

We just got a quote for 3 ton Waterfurnace Envision unit, 5 series $20,000. We live in SC. House is 1,550 sq ft. It is new construction. The system will be pond looped. Or $23,000 for the 7 series. Two questions. Is the quote comparable to what others have paid? And is there much of a difference between the 2 series? Also is there any disadvantage with having the system pond looped?

"cusp of selling snake oil"

It does seem a little greasy. They use micro-inverters. That sort of puts them one step further away from autonomous operation compared to integrated inverter-chargers. I have not run into it myself, but apparently some PV installers allow customers to believe, erroneously, that their grid-tied, battery-free systems will allow.

"if you would want to start a heat pump âÂÂoff-gridâ a 20kW backup generator would be needed. "

I'd really like to talk to an engineer who knows, but I have a feeling that the inverter units don't need as much start-up current as more conventional residential equipment does. I don't know if that is more than the fact that the inverter-based equipment is three-phase or there is more involved.