Propane (R-290) for heat pumps?

[marx290]

Originally Posted by Piwoslaw

What if an ASHP was to draw air from a solar hot air collector? Has anyone tried this?

As long as there is no air flow restriction then the slightly higher air temp would raise the HP's COP, while at worst it would be the same as with no collector.

The collector could also have a bit of thermal mass, which would store some heat if the sun is shining while the HP is off.

I think it's a great idea. I was planning on trying it two years ago with a small geodesic dome covered in PE. I was going to insulate the back or at least use a reflective material and store a couple of black plastic barrels towards the back with water or brine in them to absorb daytime rays to emit at night. Ventilation control in the "greenhouse" would be crucial I suppose. I'd love to know if anyone has ever tried something like this.