A new twist on Air Source Heat Pumps or ?
 

Saw this through an advertisement the other day and wondered what the consensus is on the product line and idea. It's called Sunpump out of Canada and they use roof mounted panels with refrigerant in them to "absorb" heat from the air and sun to make hot water and heat homes.

Interesting concept:

https://www.sunpump.solar/faq

Would it be possible to build something similar using old window units? Perhaps to heat my shop.

Search around EcoRenovator, several posts on successful backwards air conditioners.

There are better configurations here. If you look you will find these also.

-AC_Hacker

Thanks. I've read about 3/4s of the heat pump manifesto and a few other threads. I really appreciate the time you have taken to explain it all to those of us less knowledgeable.

Finding the time to go through everything here is overwhelming, so when I saw this it made me wonder what the experts here thought of it. In all my searching on here I don't remember seeing rooftop "heat absorbing" panels. Or, I may have seen them, but didn't understand what I was looking at. Most of my research has been on Solar and Geothermal.

It's a gimmick. Look up "solar assisted heat pump" and you will find many variations of the idea. There is no such thing as a free lunch. To move heat, the rig must absorb heat. When the panels absorb heat, they either overheat due to no load or become a frosty ice maker element due to more load than sunlight. In the cooling mode, the sun works against the panel. Many of these rigs have been known to explode on a hot sunny day in summer.

The rigs that actually do work well and run off solar are powered by pv panels. More panels equal more run time. Here's an example system that Ford guy is considering:

http://www.hotspotenergy.com/solar-air-conditioner/

Another problem is when those HX panels are sitting under a foot of snow.. :(

I'm using a bit of a hybrid system for my hot water. See diagram here:

http://ecorenovator.org/forum/geothe...html#post29717

If you can get some cheap PV panels, install them where you can keep the snow cleared, then you can make hotwater directly from DC from the panels.
If you have access to a basement slab sitting on 50F or warmer ground temps,
then you can run a hotwater heat pump.. As it cools the basement air, the slab re-warms the air.. It's semi-Geo-Thermal. Works good at night too..

If you took the hot water idea up in scale, you could heat your living spaces with forced hot water..

Anyways for space heating, there are hot-air DIY rigs that use collectors
to heat air pulled from the living space..
Aluminum Downspout Solar Hot Air Collector Construction, Brainstorming and Development
before pumping it back in..
These seem like the lowest cost methods and they work pretty well.

Some of us around here us warm attic air to heat living spaces.
I use attic air to warm up my basement. It would work better,
if my basement had better windows and insulated walls..

In regions where it doesn't frost overnight very often, and where it is often humid or rainy and temperate, the sunpump idea could work well. The cold panels would be very effective at condensing water trying to dehumidify the outdoor air. Likewise, rain contains lots of high density, low grade heat. The large flat plate heat exchangers would work well at night in cooling mode as well. The lack of a forced air outdoor heat exchanger has some serious disadvantages, though.

I'm very optimistic about the development of hybrid solar (PV/T) panels that are built for producing both thermal and electric power. Let me explain.

The majority of the solar PV modules available today have efficiency values in the 15 to 20 percent range. This puts them at electric production rates of about 10 Watts per square foot, or 100 Watts per square meter. To run a typical air-source mini-split unit, it needs around 800 to 1000 Watts per ton of heating or cooling capacity (counting air blower or water pump energy). So for every industry-standard (200 to 250 Watt) panel, the sun provides 1/4 to 1/3 ton of capacity, for an average of 3 to 4 hours per day.

In comparison, flat plate solar thermal panels have efficiency levels that max out in the 50 to 70 percent range. They operate against a temperature gradient between ambient temperature and collector temperature, so as they heat up, efficiency drops down towards the PV panel range. The efficiency slope is pretty linear with respect to temperature gradient, and depends mainly on panel insulation.

With an industry-standard sized PV/T panel, the ~250 Watts of PV power is generated, plus an additional 800 Watts (or less, depending on gradient) of thermal power. This relates to another 1/4 ton of heating capacity per panel! Most PV/T panels are either uninsulated or insulated very little, so that if the panels stagnate in strong sunlight, the maximum panel temperature stays under the maximum rating of the PV cells. When fluid circulates through the thermal collector, the resulting drop in temperature boosts the output of the PV cells. This set of operating characteristics lends itself very well to hot water production and heat pump systems.
http://www.engineering.com/Portals/0...rformance3.png

https://dualsun.fr/en/product/2-in-1-solar/

The most effective heat pump systems exploit both types of energy and have a small ground source loop. The electric power is used to run the heat pump compressor (or an electric boiler), the thermal power is used either to heat domestic water or the ground (depending on panel temperature and demand), and the ground loop is used to provide a source (or sink) of heat when outdoor temperature is outside the optimum range for air source operation. The ground also serves as a massive heat battery to store solar energy when it is available but not needed. The concept sounds complicated, but it's really not. All of the monitoring and control can be easily handled by a little chip inside the outdoor unit and a few sensors and valves. Of course, a custom controller adds versatility to the whole system.

Hybrid Solar Technology - Power and Heat with Solar Angel PV-T

Simple setup:
https://static.wixstatic.com/media/c...9c385d82d9.png



Complex system:
https://static.wixstatic.com/media/c...001f0df6f9.png

There is no shortage of opinions on this Forum.

Calling the SunPump a "Gimmick" is false information. Why would you say that ****? Have you ever seen one working? Or read a test report? I have, and they work well. Super smart people at NREL, DOE, and CEC are excited about the technology. So are Builders and Owners who have one in their home.

If you want facts, reach out to their Engineers at: https://www.sunpump.solar/

SunPump is for space heating and hot water. Cooling and power has been done about 5 years ago, and cooling is expected to reach California for Zero Energy Homes this Spring.

PV is complimentary to SunPump, they each do a different thing, Power and Heat. The magic of a Heat Pump is the efficiency in moving heat at 300% EF rather than creating it from the sun at a 20% EF. PV is great for lights, but sucks at heating water.

SunPump Solar Panels - Work In Snow and Can Melt Snow
 

Snow is a problem for Solar Panels generally, but Xringer have you ever seen a SunPump system heat with the panels covered by snow? :)

The truth is the SunPump Panels have been tested in Snow, and work within reason, plus they can melt snow using a defrost circuit. The measurements show a counter-intuitive mild increase in performance with dry snow. The theory is UV penetrates a modest depth to heat up the black aluminum while being protected from colder air by the snow.

I am not saying SunPump Panels work under 3 feet, but PV quits under an inch. Unlike PV, SunPump has a built in Hybrid Mode to boost the Heat Pump in Cold Snaps and operate day and night. Look at these Case Studies if you want measured results:

https://www.sunpump.solar/uncategori...formance-15244

https://www.sunpump.solar/how-to-rem...m-solar-panels

Back in the 70s & 80s, when I had a hot water system installed on my roof, I could melt it off, by forcing the HX pumps to run, pumping hot water up to the roof..But, if it was too deep, the end result was a tank of lukewarm water at sunset.

A big problem here in the Boston area, is we get warmth from the Atlantic and polar vortex air from up north.
That causes black-ice on the roads and layers of ice and snow on the roofs.
A few layers of ice inside the snow, isn't a big deal, until roofs start collapsing, then you have to climb up there and shovel it by hand.. Too Dangerous!

Had I known the difficulty of panel cleaning, with layers of ice and snow, I would have never installed that hot water system.
After a few years of repairing that system, when the double-wall HX started leaking, I was very happy to rip out the whole system.. :)