Insulating Mains and Sizing Boilers

SteamNow

Spurred by the recent discussion on insulating steam lines I've been poking around seeing how much different amounts of insulation affect head load and sizing of the system. I've got the R value table from www.buyinsulationproductstore.com and I've been playing around with it.

A common setup I see in my area is a, normally 1 pipe, boiler in a 4 unit complex with a total of about 100 or so ft of main supply line that runs the perimeter and all the feed lines tee up and off of it. Some of them have no insulation, some do. Now if I put in a pretty common amount of radiation for this area of about 200,000btu I can see how insulating the mains affects the boiler load.

It seems to be pretty huge and definitely worth the cost to insulate your entire main. In this one example, without insulation, and 100ft of 3 in pipe the total load is 930 EDR. Now, if we insulate the main with 1" fiberglass at an R value of 5.2 we end up with an EDR of 812. That's enough to drop the size of the boiler down the next rating. Even 1/2" drops the load by 10%.

EDR Without Insulation

Radiator Calculations
TOTAL RADIATION (BTU/HR)	223277
TOTAL RADIATION (EDR)	930
Radiator Output(EDR)	800
Steam Main Output(EDR)	126.3
Steam Upfeed Output(EDR)	4.1
Column Radiators	20
Tube Radiators	0
Convectors	0
Copper Cabinets	0

EDR With Insulation 1/2"

Radiator Calculations
TOTAL RADIATION (BTU/HR)	196698
TOTAL RADIATION (EDR)	820
Radiator Output(EDR)	800
Steam Main Output(EDR)	16
Steam Upfeed Output(EDR)	4.1
Column Radiators	20
Tube Radiators	0
Convectors	0
Copper Cabinets	0

EDR With Insulation 1"

Radiator Calculations
TOTAL RADIATION (BTU/HR)	194888
TOTAL RADIATION (EDR)	812
Radiator Output(EDR)	800
Steam Main Output(EDR)	8.0
Steam Upfeed Output(EDR)	4.1
Column Radiators	20
Tube Radiators	0
Convectors	0
Copper Cabinets	0

SteamBoilerSimulator0.24.xlsx