Went from 68 to 85 with my HP running for 12 hrs, with an air temp of around 80. Impressive! BTW, can I say how much I HATE solar covers....I HATE SOLAR covers. UGLY, PITA...blah blah....But yes, its necessary this time of year.
Yikes, you being up north, May and June water must be COLD without a HP. BTW, cost me $14 in EL to run the pump to get to those temps. Now it should be much cheaper to maintain the temp WITH the cover on at night. I am seeing temps in the 30's again next week though. I am guessing EL is much cheaper than what I was paying on LI, because I used to have about an additional $200-$300 a month on EL bill in May and June.I gave up my heat pump altogether. I had $6k invested in it to just sit there. *And* i wheeled it into the garage every winter.
Yes I liked not spending money on the electric bill, but 95% was how much I hated the solar cover.
IMO this is over hyped. Both of my liners went in on cool days, but the fill water was 55 no mater the weather that week. It was insta shrinkage for the floor and corners and while warm sun beating down up top may have helped it stretch vertically, it did nothing for the length and width.Liner was installed when it was a bit cold.