Often we are asked how many BTU’s are in a foot of baseboard heating.

To answer this, the following must be considered: is the baseboard heating system electric, steam or water? For this post we limit it to hot water baseboard.

Finding (1) the temperature and rate of the water passing through the baseboard, (2) the size of the copper tube and (3) the specifications of the baseboard from the manufacturer will provide a more precise answer.

We sell Argo Low Trim II baseboard which can produce 570 BTU/hr at a water temperature of 180 degrees, at a pump rate of 1 gal per minute. You can find this information at Argo’s website for Low Trim II.

This amount of BTU’s per foot, combined with a heat loss calculation, can determine how many feet of baseboard are needed to heat a room. Heat loss calculation is a complicated number to determine. It involves knowing the average outside winter temperature, how the room is insulated, square footage of the room, and number of windows and doors. There are heat loss software programs that are used to input all the variables to get a result of BTU’s required to heat a room or house. One can use a rough estimate of 50 BTUs/hr per square foot. Keep in mind that a rough estimate is just that, an estimate.

An example is that if you have a room that is 20 x 24 and are trying to determine the amount of baseboard, a rough estimate of BTU’s required would be (24×20) *50 BTU’s/hr = 24000. The number of baseboard feet would be 2400 / 570, or 42 ft of Argo baseboard.

Baseboard is often installed under windows. Can you guess why? Look for future posts to get the answer.

Links that provide more information:

- Article containing more complexities of answering the same question: PMmag.com
- Interesting conversation regarding baseboard BTU’s – DoItYourself.com