Sizing

MP1013

We were called to replace a cracked steam boiler at a small church. The existing boiler is a Burnham K5009 WTH AN INPUT OF 624,000 and 499,000 output. The churc has 7 existing wall hung radiators and 6 free standing radiators. They total 551 square feet of radiation. Using a 1.5 pickup and muliplier of 240 we come up with 198,360 DOE. which calls for a Burnham IN8 WITH AN INPUT OF245,000 and DOE of 202,000.  I would like some input whether regading this installation. The chuch itself is 30' x 40' with a peaked ceiling which goes from 20' to approx 30' at its peak. Ther are 2 mains on each side of the buildini g one being 3" about 50' long and one 2 1/2" about 40' long. Each pick up half the load. They are old existing radiators so nothing has been altered. Should I increase my pickup factor or was the old boiler just an over killl. As I said would like some input.   

Jamie Hall

IMHO,

the old boiler was overkill, and then some.  Assuming that your measurements and arithmetic are right, which I would expect they were.  That happens.  A properly sized boiler will do a better job for them, too.

jpf321

and don't forget ..

first .. I think 1.5 factor is used only when you suspect or know that rads have been removed (because at that point, there are more pipes for expected load rather than actual load) otherwise 1.333 is fine.



second .. pickup factor only matters when pipes are cold .. once all pipes are heated, the p/u factor pretty much diminishes to 0... assuming they are all properly insulated with 1" of insulation.