Minimum btu size for zone

Rob311

Hello.
I have a hot water heat (baseboard mostly) system in my house, but i want to install a new zone for a small basement. If the heater/boiler (not sure of the correct terminology) is 100,000 btu, what should be the minimum zone size be?

bmwpowere36m3

Modulating boiler? The smaller the zone the more the boiler will cycle.

Have you done a heatloss for house? For the zone you plan of adding?

Rob311

burnham series 2, so i don't think its modulating. I've done heat loss calcs for the rest of the house, although the major room heated is a 16 ft cathedral ceiling, so it ended up being a little on the cold side.

I'm just looking to put some heat into an unfinished basement which is currently unheated and i want to make sure its not going to cause an issue.

Zman

I am not sure what you are asking. The number of baseboard radiators should be sized based on the heat loss of the space and the water temp provided.
What is the heat loss for the space?

bmwpowere36m3

I was thinking he's asking about minimum zone size to limit short-cycling...

Install as many feet of baseboard as the heatloss dictates for the water temp your currently running (water temp dictates baseboard BTU output).

As far as the cold room, you could: add more baseboard, replace baseboard (I assume you have the typical kind like: Slant Fin 30 or 2000) with high-output baseboard (SlantFin 80 or Smiths HE) and/or raise the boiler supply temps. There are fixes.