Registered: 1412881494 Posts: 98
Reply with quote #1
You can think of any crazy idea... look it up , somone already had it.
https://www.viessmann.com/com/content/dam/internet-global/pressetexte/com_2013/pr-Ice_storage_system.pdf I like the idea of not having to care about a freezing waterfilled outdoor tank. I wonder how they make sure the expanding ice doesn't rip the heat exchanger tubes apart inside the tank... So the basic idea is: Connect hydronic solar collectors filled with glycol/water mix to a nearby buried water tank - instead of putting a huge tank well below ground you could put one just below the surface. - insulate it more or less, it will work at lower temperatures than the temperature used to heat your home - let a heat pump do the work of extracting the energy from the low temperature water/ice Why is this interesting? - Because of the latent heat of fusion of water to ice. (PCM) - If it is working at a lower temperature , heat loss to the environment becomes less important. - At -10F and partly cloudy weather not enough heat maybe produced to increase water tank temperature to a usable temperature (above 85F) - no need to bury hundreds of feet of pipe 8 feet below grade like a normal GSHP Now, a question remains. Will the COP of a water to water heat pump be good enough at 32F? I was basically just thinking "PCM", what could be used and was thinking of water/ice and a heat pump. Don't know if it makes sense for a residential application though.
Registered: 1352985459 Posts: 95
Reply with quote #2
A GSHP's output is often rated using 30*F input water.
COP of 3+ is common.
A well designed ground loop will approach 30*F by the end of the heating season.
I am afraid the heat pump will extract many more BTU's then a solar array could replace.