[Bldg-sim] heating and cooling capacity inconsistency

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Dear all,

I am trying to document the predicted energy performance of a 26000
ft2 christian life program building that would serve poor and
homeless. It's near 100% construction and the eQUEST energy model
results give me the following warning messages. The cooling and
heating capacities entered were directly taken from HVAC equipment
manufacturer's submittal. Is there an explanation for this or am I not
doing something right?

**WARNING**********************************************************************

A HEATING-CAPACITY of -121000. is inconsistent with a

COOLING-CAPACITY of 142840. in SYSTEM HP 1and2

**WARNING**********************************************************************

A HEATING-CAPACITY of -72700. is inconsistent with a

COOLING-CAPACITY of 85570. in SYSTEM HP 3

**WARNING**********************************************************************

A HEATING-CAPACITY of -51340. is inconsistent with a

COOLING-CAPACITY of 56240. in SYSTEM HP 12

**WARNING**********************************************************************

A HEATING-CAPACITY of -52580. is inconsistent with a

COOLING-CAPACITY of 56920. in SYSTEM HP 6

**WARNING**********************************************************************

A HEATING-CAPACITY of -74730. is inconsistent with a

COOLING-CAPACITY of 88280. in SYSTEM HP 7

**WARNING**********************************************************************

A HEATING-CAPACITY of -73960. is inconsistent with a

COOLING-CAPACITY of 87710. in SYSTEM HP 8

**WARNING**********************************************************************

A HEATING-CAPACITY of -62050. is inconsistent with a

COOLING-CAPACITY of 70110. in SYSTEM HP 5

**WARNING**********************************************************************

A HEATING-CAPACITY of -59670. is inconsistent with a

COOLING-CAPACITY of 69500. in SYSTEM HP 4

**WARNING**********************************************************************

A HEATING-CAPACITY of -58380. is inconsistent with a

COOLING-CAPACITY of 70450. in SYSTEM HP 9

**WARNING**********************************************************************

A HEATING-CAPACITY of -57880. is inconsistent with a

COOLING-CAPACITY of 69600. in SYSTEM HP 10

**WARNING**********************************************************************

A HEATING-CAPACITY of -57540. is inconsistent with a

COOLING-CAPACITY of 69600. in SYSTEM HP 11

Thanks for your help,

Ramana Koti, LEED AP

Ramana Koti's picture
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Joined: 2011-09-30
Reputation: 0

Does Table G3.1.2.9 apply to stand-alone exhaust fans? It seems that when
having a VAV system type the baseline exhaust fan power is a lot more then
the proposed design, and a baseline exhaust fan power calculated using the
constant volume calc gives a more reasonable baseline. Any thoughts?
Kevin

Kevin Kyte's picture
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Joined: 2011-09-30
Reputation: 0

Kevin,

The values in Table G3.1.2.9 gives a total for bhp for the sum of all fans in each HVAC system, which includes "supply, return, exhaust, and relief (excluding power to fan powered VAV boxes)". Not for each separate fan. The exhaust fan is most likely exhausting air that has been supplied by some HVAC system and its bhp would need to be included in that systems calculation. I think that section of Appendix G is poorly written and could be clarified.

Michael Rosenberg

Does Table G3.1.2.9 apply to stand-alone exhaust fans? It seems that when
having a VAV system type the baseline exhaust fan power is a lot more then
the proposed design, and a baseline exhaust fan power calculated using the
constant volume calc gives a more reasonable baseline. Any thoughts?
Kevin

Michael Rosenberg's picture
Joined: 2011-10-01
Reputation: 0