Is Your Air Conditioning Working



Posted: Monday, May 29, 2006

by Michael Del Greco Licensed Home Inspector
Accurate Inspections, Inc

Properly functioning air conditioning systems have a temperature drop of 14 to 20 degree temperature difference between the supply and return ducts when it is above 75 F degrees outside.

If this temperature drop does not exist the air conditioning system must be cleaned, adjusted, repaired and tested by a qualified person. The service person must be asked to provide certification no refrigerant leaks exist, that the system is operating effectively after the necessary corrective action has been taken, or perform the necessary replacement(s). Systems that are leaking refrigerant can not be legally refilled becaue leaking refrigerent can be hazardous to the enviorment.

Systems that are low on refrigerant can "self destruct". If a home owner tells you the system does not work because it was not filled up for the season that is an indication there are serious problems with the system (like leaks they can not fix). Keep in mind refrigerant leaks will not be found during a standard home inspection.


Michael Del Greco is President of Accurate Inspections, Inc. A New Jersey home inspection firm. He has performed thousands of home inspections in New Jersey since 1993. He has taught the New Jersey Home Inspector Licensing classes and New Jersey Home Inspector CEU classes as well as participated in developing questions for the National Home Inspector Exam. Michael's home inspector resume may be viewed at http://www.mdelgreco.com

Visit http://home-inspector.NewJerseyHomeInspection.com for a list of home inspectors in New Jersey.

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Top-level comments on this article: (3 total)
» left by Anonymous
 4 years 327 days ago.
helpful info to understand a home inspection report
» left by Curt
from NC 3 years 343 days ago.
Need reference to statement re normal TD 14-20 deg. I know this is taught to inspectors but no further explanation is provided. In particular, low efficiency units have higherTD than high efficiency. And it varies with outside supply temp. Is there a manufacturer reference available?Is an AC which is one deg. out, ie, 13 deg. TD, out of spec? Otherwise.. Thanks for the info.
» left by HVAC Guru from New Orleans 2 years 323 days ago.
What Curt said is absolutely true and it is surprising that this temperature drop "rule of thumb" continues to be taught year after year from home inspection schools where one would think there would be some extra thoroughness in researching the material that is taught.
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