Water Temp. to use Sizing Baseboard Heat

Brent H.

I've run a heat loss on the master bedroom in my addition and determined I need 7600 BTU/H. What do you guys commonly use as a safety factor and what water temp. should I use calculating the amount of Slant Fin 30 baseboard? My boiler has the high limit set to 185.... since I assume there will be loss running to the baseboard and also between the start of the baseboard and the finishshould I use 170?

Thanks for the help.

CMadatMe

Size the board

For what temp you need at your design temp. In my case here in NY my design temp is 0. See the chart I attached for the ratings. The lower the water temp you start with the lower the out-put of the board so the more footage of board you will need to overcome the heat loss at your desgin temp.

Brent H.

Followup

Looking at the chart is caused my initial questions

The heatloss was done with a design temp. of 0 for Worcester, MA. For a boiler with 185 degree high limit, should I use the 180 degree BTU output in the Slantfin chart or 170 degree to figure in some loss? Also, my heat loss program assumes a 20% safety factory.... is this too much?

CMadatMe

Size for 180

Use the 610 a foot for 180. If you boiler water temp is leaving 185 your return water temp should be 165. Don't lower the water temp unless you plan on doing a heat loss of all the other rooms and making sure that the footage of board in those rooms can overcome the loss at 170 degree water temp.  Don't worry about pipe loss. Worry about supply/return temp.