Total E.D.R.

[opoplectic]

I came across a set of mechanical drawings from the 60s and there is reference to "Tot. EDR" in the AHU Schedule under the heating coils. I found out that Tot. EDR means Equivalent Direct Radiation.

Question is how do I convert to MBH.

thanks

 

[TBP]

Each square foot of EDR is equivalent to 240 BTU when the coil or radiator is surrounded by 70*F air, and there's steam at 1 PSIG in it.

 

[TBP]

OK - I found the calculation for steam & hot water. It's delta-T (rad to air), in *F, multiplied by 1.6.

With an air temp of 70*F, and an avg hot water temp of 160*F would be:

(160 - 70) X 1.6 = 144 BTU

If you had steam at 5 PSIG:

(227 - 70) X 1.6 = 251.2 BTU

 

[opoplectic]

thanks