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Difference being, any foam fulled spa with no insulation surrounding the equipment compartment would have frozen pumps lines, element, etc...while the Arctic is still above freezing. No way uninsulated components full of water do not freeze in that time period. Regardless of heaters, blankets, your wife's hair dryer, etc.....
I have been working on spas for 9 years and I can honestly say that I have seen Hot Spring equipment comp. freeze in less then 24 hr. Sure the water up top was hot but the heart of the system frozen solid. 3/4 lines don't take long to freeze. On the other hand the Arctic spa does not have foam on back of the spa shell, so if there was a power outage the heat transferes back down to equip.(a basic rule). Now if this spa was installed in a climate where freezing doesn't happen there are still benifits of keeping all the wasted heat energy from motors(not just freezing) now your electric element doesn't have to turn on as offten to maintain heat in spa, less power usage means more money in your pocket. I think it just makes sense :-/