10 years or so ago I built my own roughly 3’ X 4’ back wall heat panels by sandwiching 3 strips of 11” heat tape between two concrete boards. Proportional thermostat probe is on the shelf just off the surface of the heat panel in the middle of the center strip. In the winter surface temps of the heat panel need to be in the low 100s to keep the thermostat probe in the mid 90’s and the very back of tub low 90s. Has worked well for a decade but now noticing the surface temp over one of the tape strips on the edge of one of the panels is only mid 80s sometimes. So thinking time to disassemble the panels and put in new heat tape. Can’t remember for sure but suspect I originally used Flexwatt (can’t check until disassembled).
Anyone have a strong recommendation for one brand over the other? The difference in price is negligible compared to the work to disassemble my homemade melamine shelves, side wall mounted rails, and back wall mounted heat panels. I just want whichever will hold up longer while heating evenly.
Side question. The heat strips are each 3’. Is it worth connecting one wire to one end and the other side wire to the other end to try reduce voltage drop along the length of the tape due to resistance in the side strips?
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I have many feet of both in use, though more Flexwatt. I’ve also used Flexwatt for longer – 2 decades vs one, more or less. I have a preference for the Flexwatt, as I think the tape itself lays better (less rigid, maybe?) and I do get along better personally with the Flexwatt connectors. But either should work fine, and at least part of the decision might be which is easier for you to get ahold of or what retailer you prefer to buy from.
As to your side question, I don’t quite understand how your fix would reduce voltage drop (same length of conductors in both scenarios), but doing so isn’t a goal here anyway – any loss of power because of resistance in the materials will be realized as heat, which in the current application is exactly what you need.
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Thanks! I’m leaning towards Flexwatt. Will order before Monday.
My thinking on the connectors is that MAYBE there is a non negligible voltage drop along the length of the side connectors (maybe more than in the extension cord wires I solder to them). IF this is the case and I solder both wires to the two side rails at the same end of a 3’ piece of heat tape for wiring convenience the electricity through the first heating element at that end doesn’t have to travel through much of any side rail at all. But the electricity through the last heating element has to travel 3’ down one rail, across the heating element, then 3’ back up the other rail for 6’ total.
If instead I solder the electric wires to opposite ends every element path includes the same 3’ of side rail, just varies how much of that 3’ is on each side of the element.
Probably the rail resistance is so low (maybe close to as low as the extension cord) that it doesn’t matter for such short pieces of tape. Maybe if it was a 20’ piece of tape with a 40’ path for last element you would be able to notice the end of the tape testing cooler due to the heating elements toward the end having a lower voltage due to 40’ more rail travel than the other end.