I have a '94 cal spa that I have been rebuilding. I am ready to begin reinsulating and noticed there is no insulation between the hot tub and the area with the pumps and controls. Does anyone know if this was intentional to keep the pump area from freezing or if this could have some insulation added. It seems like a large area to be left uninsulated. I am also hoping to insulate the pump area some. Though I am not sure at this point how much I will be able to get around that area
Thanks Tim

A couple reasons this may be left uninsulated. First, room. Equipment takes room and different models had different equipment, so to be sure to have enough space, some manufacturers leave this uninsulated.

Another is some spas utilize the heat generated from the equipment to help heat or maintain the spa temperature.

Some heat from the spa may be used to help keep the equipment from freezing, but I think this would be somewhat unlikely. If it's that cold around there, the pump/heater should be running.

I would insulate the panel that goes in front of the equipment bay to help keep the heat in there.