[BLDG-SIM] Heat Pump COP

[Michael Blasnik]

A somewhat minor point, but I think you have mis-read the test standard.  The 
0.05 inch ESP is the tolerance allowed under testing conditions, not the actual 
ESP level.  Table 2 on page 59149 shows the minimum ESP for testing ranges from 
0.10 to 0.20, varying as a function of rated capacity.

Michael Blasnik
M Blasnik & Associates

----- Original Message ----- 
From: "Brandon Nichols" <BrandonN at Hargis.biz>
To: <BLDG-SIM at gard.com>
Sent: Tuesday, October 16, 2007 1:53 AM
Subject: [BLDG-SIM] Heat Pump COP


OK All,

Has anyone looked at this lovely document
<http://www.eere.energy.gov/buildings/appliance_standards/residential/pd
fs/cac_tp_101105.pdf> , which is the Department of Energy's test
procedure for air conditioners and heat pumps to determine EER and SEER?
To this I turned to answer the burning question "what is the standard
external fan static pressure drop specified to calculate EER and SEER?"

Seems to me after wading through the swamp of equations in the back of
the document that fan energy in EER and SEER calculations is specified
at a 0.05 inch external static pressure drop.

So then I started digging around for data to support my intuitive
feeling that fan energy is going to be something like 1/10th that of
compressor energy on small heat pumps.

In the process I ran across this nifty DOE/ORNL Heat Pump Design Model
<http://www.ornl.gov/~wlj/hpdm/doehpdm.shtml> .  Now we're cooking...
see this post
<http://elcca-exchange.blogspot.com/2007/10/heat-pump-parametrics.html>
for a 3D plot of parametric runs (did I say 'nifty'?), varying supply
airflow and static pressure, from 600 to 4200 and 0.05 to 0.65
respectively.

I'm standing by my assertion that supply fan energy does not need to be
subtracted from heat pump EER as SEER and the new number recalculated --
playing those kinds of games can lead to an exercise in futility.
<http://www.ornl.gov/~wlj/hpdm/doehpdm.shtml>
Best regards,


Brandon Nichols, PE, LEED(r) AP
Mechanical
HARGIS ENGINEERS

600 Stewart Street

Suite 1000

Seattle, WA 98101

www.hargis.biz


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