***and where does the air come from that replaces the "90 degree" air from inside the cabinet... the "15 degree" air no? Â The blown air doesn't get heated in either case***
Of course the air from outside of the cabinet eventually ends up inside... it's not "sealed", but the blower takes a LOT longer than 1 second as someone suggested to use up all of the warm air within the cabinet. Â (certainly you MUST be joking!)
I definitely agree that HS has one of the best systems for this I've seen on that type of spa... HS has one of the best engineered tubs on the market.
I can run a thermospa for 30 minutes, Â then remove a panel, and the inside air is a LOT warmer than the outside air! Â I'm guessing it's still well over 70 degrees! (I'm going to test this with a thermometer)
As far as someone saying the blown air doesn't get heated, it may not get heated "directly", but with a thermopane tub the pumps, heater and blower all constantly create heat, (as shown in Chas diagram) and it warms the air inside of the cabinet. Â
Keep in mind as well, that the heater is heating the water, and the 103 degree water temperature also aids in warming this air, before it enters the blower.
Z