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I was recently in a dealer who carried only full foam tubs and he was saying that the cheaper ones are thermopannel and the LIPA (Long Island Power Authority) Â has tested the full foam and showed they are very very energy efficient. Â I thought the thermopannel were effficent too until he told me he raw hard data.Just wondering if anyone else had any thoughts. Â FYI the spa I also saw did not have an air blower. Â I personally would really miss it.
The truth:1. Heat rises. It finds the path of least resistance to escape.2. In an average climate you loose 90% of you heat through the cover (or where the cover meets the spa)
Sure sounds good. Unfortunately, it is completely wrong. Â If you take a poorly insulated tub and put a great cover on it, you will still pay a fortune to keep it hot. 8-)
So the study that shows that in an average climate (Southern California to be exact) you loose 90% of your heat through the cover or where the cover meets the spa. Are you saying that is incorrect. Â
I suggest pouring a tall drink, get a snack, find your most comfy chair (although you didn't sit in it prior to buying it  ) and search the PAGES of debate on this subject over the past 5 years on here benalexe...nuff said...
Now, as for more heat escaping through the cover compared to the sides of a spa.... well, figure out the R values. The average cover is R-12 - R-14. Put 6" - 10" of full foam insulation around a spa and yeah, way more heat will travel through the thinner cover.