Does anyone here have good familiarity with Solar A/C?  

I know this is a GSHP forum, but, I don't know where else to post, and I'm highly respectful of the professionals who contribute their valued time here to help others.  And maybe I'll discover that Dana1 is an expert in another subject too!

I’m specifically looking at a company named SunTrac Solar ( see http://suntracsolar.com ), who claim up to 40% savings in cooling and heating costs, from 1 to 500 ton units.  Fundamental is that the unit has to have at least a two-stage compressor or a variable capacity compressor.

Fundamentally, how is SunTrac Solar taking thermal energy and using it to otherwise do the work the compressor would do.  How are they taking thermal energy and converting it into an efficiency action for so much HVAC efficiency improvement?

What lends credibility to the claims is that the ‘big boy’ compressor companies are approving SunTrac Solar’s product being used to manage the refrigerant line temperature and manage the speed of the compressor.
 
Daikin, Emerson, Copeland, and one other compressor company now authorize replumbing the refrigerant line through the solar thermal panel. It’s one panel for every 7.5 tons of cooling. If you listen to all of the principles, SunTrac Solar, Global Wide Green, and Solar Assisted Products, they have quite a product!
 
Any assistance understanding how the technology works would be appreciated.  Or if this is a worthy energy efficient action.

And if there's a better place to post this, that help would be appreciated too.

Many thanks!

Best regards,

Bill

Got nothing, but please share what you learn

Could be a SCAM

S= Smart
C=Criminals
A= After
M= Money

Posted By Palace Geothermal on 25 Apr 2015 10:28 AM
Could be a SCAM

S= Smart
C=Criminals
A= After
M= Money

I just don't know at the moment.

Some random observations:

1. In Texas you don't see much solar thermal anything anymore.  It does require some maintenance, and, HP hot water heaters are now getting pretty efficient without otherwise requiring the solar thermal panels for hot water.

2. I wouldn't think the compressor 'big boys' would be inclined to authorize and warranty their compressors when the refrigerant line is modified, unless the science is sound.

3. I just don't see any solar thermal panels on commercial rooftops here in the Dallas area at least.

4. So far I have no M&V data, from anyone, that proves the efficiency improvement.

Thanks.

Best regards,

Bill

They are being remarkably circumspect about the details of how it's supposed to work. Even absorption chillers need cooling towers.

I need to see a visual on the thermodynamic flows on how this works in AC mode when integrated into a conventional split system, maybe even some of the math. There's a whole bunch going on that they're NOT sharing.

Some of the buried non-insulated tank water-to-water heat pump systems can work at high efficiency in either cooling or heating mode, taking advantage of low tank temps to be able to get reasonable solar thermal efficiencies even in cold climates, leveraging it with the heat pump. In those systems the heat of fusion of water gives it a lot more "apparent capacity" when the tank temp hit's 32F, which is not a particularly inefficient temp for a W-W heat pump to work from. And at 32F storage temp you can still get pretty good collection efficiency out of cheap solar thermal flat panels even when the outdoor temps are in the teens. The tank doesn't need to be insulated if buried, since it takes on heat from the soil in winter, and dumps heat into the soil in summer.

A pretty sharp hydronics guy in NJ has telling me that these buried tank systems are cheaper and more efficient than ductless air source heat pump solutions in cold climates, but he hasn't shown me any budgetary financials on it. I can believe a solar thermal buried tank W-W heat pump solution (or even a massive insulated tank in the basement) could come in cheaper than drilled GSHP in southern New England GSHP prices though. The solar adds complexity to the system, but it reduces the complexity (basically eliminating the necessity) of the ground coupling end of the system, and runs at temp where you can still get decent solar thermal input out of a small thermal array, even in the middle of heating season. (He's also a big fan of the SunDrum therma l+ PV hybrid approach, since the thermal cools the PV, yielding higher summertime PV output.)

double post deleted

Dana, much appreciated!  Bill

Feels scammy - lots of sizzle, no hard facts.

We are proceeding with SunTrack Solar.

We can't pass by the opportunity to bundle LED lighting upgrade projects with a solar improvement that makes the whole project eligible for the 30% tax credit.

We have a Trane unit that we're going to try this with.  Since the unit only has a one stage compressor we're going to replace the compressor with one that's compatible with STS.

More as we learn.

Best regards,

Bill