Hybrid system

[Pappio]

Anyone have any knowledge or experiences with using solar air heating panels to supply heat to a heatpump? Was thinking early morning or later afternoon when sun heating is diminished, a hybrid system would boost the efficiency of the panels for small energy cost.

[Naptown]

My first thought would be no due to the massive quantities of air needed for an A-A heat pump. Static pressure would be huge unless there were massive amounts of collectors and airflow. Better to build an air collector and use that directly for heating.

[Pappio]

Probably right. But, an A to A heat pump is designed to extract heat from air that is much cooler than what would be coming from a solar collector system. The higher heat content from a collector would allow the system to run with less air passing through it. Maybe enough to offset the problems, maybe not. Anyone tried it?

[Teabo]

downspout collector to heat pump inlet

I just built a lake home in southwest Missouri. I heat and cool the 1500 sq ft living space with a couple of PTAC units. (Commonly referred to as Motel Units) They are Carrier 52CQ units. Each has cooling capacity of 12,000 Bthuh, and heaters of 3.4 kW. In reading the manual, I found:
"When the temperature of the outside coil reaches 20 F (approximately 35 F outdoor air temperature) the compressor will shut down as unit is no longer adequate heating in heat pump mode. The electric heater then becomes the primary heating source. The electric heater remains on until the temperature of the outdoor coil reaches 40 F; then the electric heater is shut off and the compressor is energized. Once the compressor is energized, the heat pump again becomes the primary heating source."

My thoughts are if I can raise the air going across the outside coil by a few degrees, then my heat pump will continue to operate instead of the expensive heating coils. It doesn't have to be a lot of heat added, just a good air flow and minimal heat. I want to make a low restriction air path. I plan to use downspouts to make a long (almost) hidden collector. I'll keep you posted with the results.

[J.P.M.]

Anyone have any knowledge or experiences with using solar air heating panels to supply heat to a heatpump? Was thinking early morning or later afternoon when sun heating is diminished, a hybrid system would boost the efficiency of the panels for small energy cost.

Back in the 70's there was a lot of talk and some work done using air collector/ heat pump interface. Seemed a marriage made in heaven, but more wishful thinking than practical as the dearth of such systems will attest. Perhaps better heat pump C.O.P.'s and designs have changed the economics, but I doubt enough to make it cost effective. Maybe I'm wrong.

[russ]

Look at the airflow through the unit (atmosphere side) and you will be surprised how much air you would have to heat to make a difference.

[Mike90250]

I think you should concern to professionals.

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