Boilers

Question 1

High temp hot water boiler

Answer 1

Over 120* C (250* F)

Usually rated in MBH or BHP

Question 2

Boiler points

Answer 2

1BHP = the ability of a boiler to evaporate 34.5 lbs of water/hr
34.5 lb/hr x 970 BTU/lb water (latent heat) = 33.475 btu/hr/BHP
1 hot water EDR = 150 btu/hr @ 71C (160F)
Net rating = 75% of the gross rating

Question 3

Gross output

Answer 3

% of efficiency = gross output in BTUs / input in BTUs x 100

Question 4

Low temp hot water boiler

Answer 4

Max temp of 120C (250F)
Max 1100 kpa (160 psig) except for conventional cast iron boilers which have a max of 207 kpa (30 psig)
Usually rated in btu/hr or EDR,and net rated