Posted by Harold Kestenholz - Hydronic Network on April 05, 2001 at 15:17:10:
In Reply to: Can I add to my steam system? posted by Robert Niosi on April 05, 2001 at 14:40:30:
You and anyone else will be guessing and hoping it will work. A 3/4-inch branch on a 2-pipe system may take up to 30 square feet of equivalent direct radiation (c. 7000 btuh). If the two rooms require that or less, you might be able to heat them both if piped correctly.
You can do a heat loss calculation for free at http://www.hydronic.net
When you do add more radiation, it is also possible for the additional radiation to exceed the amount of steam that the boiler provides, so correct piping may not even do the trick.
You need to find the heat loss of the rooms served by the steam times 1.5 vs. the amount of steam the boiler can provide in btuh.