RBI Rack Heat Tape Questions

[kitedemon]

From a thermodynamics standpoint that doesn't make sense. When heat enters the system via a large heating element it doesn't simply remain at the floor of the tub. Energy will equilibrate to cooler areas and in an insulated system using plastic tubs and pvc it will hold ambient temps great. Again, I have used temp guns and quality thermometers to support this.

It is a radiant heat source. Not a convection. heat enters heats what ever object it points at and that it turn heats the air associated with it. A plastic tub has no mass or density to hold and carry that heat so there is a massive amount of heat loss. The rack have very poor insulation so it too losses heat faster than it can be added with such an inefficient heat source. It is like trying to heat a swimming pool with an aquarium heater. It looses heat faster than it can be added. UTHs do not effect air temps to any significant degree. One or two maybe possibly 3-5 if you add heavy stones and such but generally they don't make a significant difference to air. this is why radiant heat sources are used in rinks they heat the people but don't increase the temperature of the air in a significant way.

Temp guns cannot measure air. My rack runs in a room temp of 68ºF I have 11w flexwatt and hold a stable 90ºf in the tub. the base air temp is only 70ºF, I add 2ºF to the air. that is in a 1/2 inch PVCx fully enclosed rack. Anyone with an enclosure in a cool room and just a UTH and nothing else will say the same thing the air is too cold.