Really Long Baseboard Heaters
One of the differences between hot water and electrically powered baseboard heaters is their standard available lengths. While electric baseboard heaters generally max out at 6 feet, hydronic baseboard heaters can run 30 feet and beyond!
Surprised? You shouldn't be. It's really about laziness. More on that in a moment. But for those with rooms containing long length heaters, renovations of the old decrepit covers using easy slip-on Baseboarders will require a little extra attention.
The hydronics industry has for years produced nominal lengths of 2', 3', 4', 5', 6', 7' and in some rare cases 8' and even 10'. Shipping considerations are obviously the determining factor in how long a single integral cover can go. Wholesalers of baseboard heaters know full well the horrendous accounts of freight damage when dummy covers longer than 6' are moved around. So lets get right down to the important considerations for really long baseboard heaters:
Sagging of the Element
Finned tube elements will start to sag after about 6' without sufficient support along the length of the copper pipe. When dealing with a sagging element, try to ensure the existing brackets that are designed to support the element and positioned properly. In situations where the original back plates have also been removed, or in new construction situations, try using some copper wire. One end of the wire can be wrapped around a short bare section of pipe while the other end, at a wall stud location, can be screwed in place. Alternatively a wood block or some other non-conductive material can be positioned below the element to act as a support.
Calculating Cover Lengths
Let's say you've got a 237" length run of baseboard heating. I've taken some crazy random number to demonstrate any length can be easily covered using multiple panels. How will you calculate the lengths of Baseboarders needed to accurately cover this long run? We'll want to focus on the least number of panels to keep the costs minimized.
Start with the longest single integral panel length available: 84" (or 72" for Basic series) and find out how many full 84" (7') lengths can be used.
We do this by taking the measured length in inches (237" in this case) and divide by 84. That gives us 2 full pieces of 7' plus a remainder.
We now know we can only get two standard 7' panels on this heater. Find out how many inches remain. (237" - (84" x 2)) = 69".
The remaining 69" will be covered using a standard 6' panel cut down to 69".
When two baseboard heater cover panels are placed side by side on a long run, there needs to be a form of end to end registration. A coupler or "joiner" piece is slipped in spanning a little more than an inch over each panel to ensure the joint is secure and visually easy on the eyes.
And all this effort just because of laziness? Yes it's true. Hot water baseboard heaters are just the tip of an infrastructural iceberg. Below the floor boards are many more feet of bare copper pipe that snake through the floor joists in big loops that start and end with the boiler. Every time a heater is located above the floor, copper pipe has to be cut, "elbowed" 90 degrees, run up through the sub-floor, elbowed again, connected to the finned tube element, and so on. It's a lot of work for the plumber. So if a 15' length of wall is available, why not use the entire length to run a heater? And that's why hydronic baseboard heaters very often run in lengths far beyond 7'.