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How much baseboard??

Finishing the basement in our new house. It's below grade, has 2 single pane tilt-in basement windows (13"x31")in the room, and the walls will be 2x3 construction with R-11 insulation. Room dimensions are 20x24x7. Need to figure out the linear feet of baseboard required to heat the finished room. It's forced hot water at 180*. Thanks for any info. -Mark

JacktheShack

Mark:

Basements can be tricky to calculate because there are so many variables:

1) The biggest one is what is the temp in the basement now; the boiler and associated piping, if located in the basement, will contribute a lot of heat & thus affect how many feet of baseboard required.
2) What is your location? If you live in the far north, you will need more baseboard, than if you live in the South, or somewhere in between.
3) Does your frost line extend 3' down the basement walls, & is most or part of the basement walls not covered with soil??, etc., etc.

They have designed Heat Loss Calculators to address some of these variables; you can try some of the free sites below.

Aside from the variables above, a general "rule of thumb" way of calculating how much baseboard, is to assign 30 or 40 btu/hour to each square foot of basement space.

The other factors, such as how many btu's of heat a foot of baseboard puts out per hour is known to be 580 btu/hr.

Heat Loss Calculations try to estimae how many btu's of heat are oozing out of the walls, floor, ceiling, windows, etc, per hour so that that same equal amount of heat can be replaced by the appropriate length of baseboard to keep the basement warm.

Thus, a basement 20 X 24 = 480 sq.ft. X 30 = 14,400 btu/hr divided by 580 (baseboard btu/hr) = 25' of baseboard needed for the basement.

If the boiler is located elsewhere, or there are no exposed boiler pipes, the figure might be: 20 X 24 = 480 sq.ft. X 40 = 19,200 btu/hr needed divided by 580 = 33' of baseboard needed.

If you have a computer system that loads files quickly & is not dial-up, try loading the free Slant Fin HLC, which is comprehensive & includes basement calculations; at the Slant Fin site, click onto the heat loss reference.

The other HLC's are more rudimentary, & thus not as accurate.

Some of the HLC's specify you enter the square footage of the entire house, or of a single room; but you can treat your basement as a single "room" for entry purposes.

There is more info on the internet for basement heat loss variables, if you Google "heat loss calculation" basement.

It is recommended that your convector/piping hookup to the boiler be done by creating a separate zone for the basement baseboard; this is usually done by adding a zone valve (Taco recommended) and a separate thermostat; this is a relatively simple, low-cost install; sometimes a zone circulator and flow check valve/thermostat is installed instead of a zone valve.

Copper tubing has traditionally been used to connect the baseboards; but due to the skyrocketing price of copper, PEX plastic tubing is now widely used with the appropriate brass connectors instead of copper to save \$\$\$.

Connecting piping for the baseboard and the baseboard itself are always installed along the exterior walls of the basement, if feasable; the connective piping would have to be installed inside the 2 X 3 frame walls BEFORE the insulation & sheetrock is applied; the system MUST be air-pressure tested to 20 psi, or operationally tested for leaks BEFORE the sheetrock is installed.