i'll ask again

Brad White

a condensate receiver (surge tank for large systems) for at least 20 minutes of storage time and the pump flow rate for three times the condensing rate. For normal transfer, I would figure 5 minutes or take whatever manufacturer's matched standard offering which usually has a 3.0 pumping factor.

I never back-calculated so let me try for your case using these parameters.

For 8,000 SF EDR (1,920,000 BTUH or 2,000 PPH):

20 minutes flow would be 667 PPH roughly. Divide that by 8.33 lbs. per gallon to get gallons, I come up with an 80 gallon receiver for a surge tank and 20 gallons for a normal transfer receiver. A pump would be 12.0 GPM for that EDR rating by the way.

(Hint- use a 1.5 multiplier per 1,000 EDR. In other words, a 6,000 EDR receiver pump would be 9.0 GPM (6 from the 6,000 x 1.5 = 9.0). A 20,000 EDR would be 30 GPM, etc.) That works out to 3.0 times the condensing rate.

For normal receivers in that EDR range, Skidmore for one offers a 21 gallon and 45 gallon receiver, with 21 gallons predominating. Not until you get to 45,000 EDR does a 45 gallon receiver become the baseline. A 110 gallon receiver is also available starting at 60,000 EDR at least in the Skidmore line.

I often specify a larger receiver as it buys me some return diversity such as in a campus situation and match the pump rate to the receiver. The foundry folks tend to like me :)

[Deleted User]

i'll ask again, but

i'll re-phrase the question;
if i do the math in reverse from a 45gal receiving tank, i get the sqft edr of approx 40k. does this sound correct regarding the cond pump/receiving tank/boiler size?
ie, 286bhp

bobbyg_2

I am assuming you are talking about a steam boiler feed tank?

the link below lists sq.ft.edr and boiler HP.
http://www.hoffmanspecialty.com/pdf/hs900/HS900-HBF.pdf

another good resource:

http://www.skidmorepump.com/

"click on: literature"
then "click on SELECTION GUIDE"

[Deleted User]

yes, a steam bolier

but a condensate receiving tank.
and the reason i ask is because, in holohan's 'lost art' book, on pages 174-175, he does the math for an 8000sqft/
erd/60hp boiler, and comes up with a need for a "gross" capacity 9gal tank.
misprint? am i reading it wrong? is his math off? am i completely lost?

and bg, thanks for the reply