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Are there any documented energy studies regarding the benefits of spa blanket? I would even settle for a home study. I can't imagine a spa blanket could add any substantial insulating properties in addition to a modern insulated cover. I would love to be proved wrong though. If I could save $10/month or more I would give it a try.
I think the energy savings come from IF the blanket seals the water completely since dry air conducts heat slower than moist air. And the fact that convection currents are off the water.I will say that I believe these savings are minimal and shouldn't be the reason for the blanket.I purchased the blanket to be my sacrifice for the chemicals. As I've said I have about 95% of the water covered so that's 95% less water surface for ozone and chlorine off gassing to affect my cover. I also got away with not filling up the spa too often during the winter. Reading that people put water into their tub every week during the winter, I went 3-4 weeks. I don't use the tub every day but do use a suit when I go in and it takes out some water when I get out ... If that's any indication of less water evaporation, then there's some proof of something.I originally was going to put the blanket onto the cover as was discussed here in the past but my cover isn't "the very best", it's nice but it does have some gaps and I thought that I should have something closer to the water. Once this cover goes and I buy a better cover I might not use a blanket.