Existing Window Units (UNCLASSIFIED)

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I'm working on an energy audit for a building with old window A/C units. The average age is about 15 years old. Does anybody know where I can find a good estimate for the efficiency of a 15 year old unit?

I know there is a wide range of efficiencies, then and now, depending on how much you are willing to pay. I'm looking something I can reference and file in my report to show where I got my numbers.

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Jeurek's picture
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I have a little older than that. This figure is from
LBNL-40297 "Energy Data Sourcebook for the U.S. Residential
Sector" also attached where RAC is for room air conditioners.

Jason

Jason Glazer's picture
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Hello John,

I'm not sure if this this is what you?re looking for, but here's a table from a 33-page report (full report attached) by Southern California Edison Company, written in October 2007. It covers a.c. EER values 25 years ago and 15 years ago.
Working Paper WPSCREHC001, Rev. 1. Title: ENERGY STAR ROOM AIR CONDITIONERS.

Table 4: 1605.1 (b) Table B-2 Standards for Room Air Conditioners and Room Air-Conditioning Heat Pumps
Appliance Louvered Cooling Capacity Minimum EER
Sides (Btu/hr) Effective Effective
Jan 1, 1990 Oct 1, 2000
Room Air Conditioner Yes < 6,000 8.0 9.7
Room Air Conditioner Yes ? 6,000 - 7,999 8.5 9.7
Room Air Conditioner Yes ? 8,000 - 13,999 9.0 9.8
Room Air Conditioner Yes ? 14,000 - 19,999 8.8 9.7
Room Air Conditioner Yes ? 20,000 8.2 8.5
Room Air Conditioner No < 6,000 8.0 9.0
Room Air Conditioner No ? 6,000 - 7,999 8.5 9.0
Room Air Conditioner No ? 8,000 - 19,999 8.5 8.5
Room Air Conditioner No ? 20,000 8.2 8.5
Room A.C. Heat Pump Yes < 20,000 8.5 9.0
Room A.C. Heat Pump Yes ? 20,000 8.5 8.5
Room A.C. Heat Pump No < 14,000 8.0 8.5

If you want the full report in Word Document format, Google ?Work Paper-Energy Star Room Air Conditioners?, then click & download the URL that shown [DOC] Work Paper-Energy Star Room Air Conditioners. This will be the 33-page 2007 report.

Regards,
=============================
Larry O. Degelman, P.E., FIBPSA
Professor Emeritus of Architecture
Texas A&M University
2206 Quail Run
College Station, TX 77845
ldegelman at suddenlink.net
=============================

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Larry Degelman's picture
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This is a great place to start. The 15 year old units certainly won't
be *better
*than these values.

I wonder how much *worse *they might be due to poor installation, corroded
and clogged evaporator and condensing coils and other wear and tear? 20%?
30%?

James V Dirkes II, PE's picture
Joined: 2011-10-02
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