[Equest-users] Cooling Tower EIR for LEED projects

[James Woodard]

Hello all,

I am a large manufacturing plant with a Baseline system #7, and in particular looking for information regarding the Cooling Tower EIR to input. The conundrum I have is getting the tower appropriately sized @ 38.2 gpm/hp at the correct conditions. ASHRAE 90.1 Table 6.8.1G gives this value of 38.2 gpm/hp at 75/85/95.

By trial and error, we have developed that 0.0114 EIR corresponds to 38.2 gpm/hp at our design conditions 80/85/95.

The eQuest help file reveals that the default EIR for open towers is 0.0105, which corresponds to 0.0154 hp/gpm at 75/85/95. By linear regression, this equates to an EIR of 0.0178 for the 38.2 gpm/hp (notice the inversed units). Am I cheating by entering this value for my towers even though my design conditions are 80/85/95? I have seen/heard of people inputting this value independent of the design conditions, but I'm not sure if they changed the design conditions in the Basic Specifications Tab of the Cooling Tower (and if so, did the Proposed input conditions change too?).

What is everyone's take on this subject?

Thanks,

James Woodard, E.I.T., LEED AP BD+C | Mechanical Engineering

BRPH | 5700 North Harbor City Boulevard, Suite 400 | Melbourne, Florida 32940
O:  321-751-3150 | F:  321-259-4703
jwoodard at brph.com<mailto:jwoodard at brph.com> | www.brph.com

ARCHITECTS | ENGINEERS | CONSTRUCTORS

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