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AIR CONDITIONING & HEAT PUMP SYSTEMS

A/C - HEAT PUMP CONTROLS & SWITCHES
AIR CONDITIONER BTU CHART
AIR CONDITIONER COMPONENT PARTS
AIR CONDITIONER TYPES, ENERGY SOURCES
AIR CONDITIONER NOT WORKING
AIR FILTER EFFICIENCY
AIR FILTERS, FIBERGLASS PARTICLES
AIR FILTERS for HVAC SYSTEMS
AIR FLOW MEASUREMENT CFM
AIR HANDLER / BLOWER UNITS
APPLIANCE EFFICIENCY RATINGS

BACKUP HEAT for HEAT PUMPS
BLOWER DOORS & AIR INFILTRATION
BLOWER FAN CONTINUOUS OPERATION
BLOWER FAN OPERATION & TESTING
BOOKSTORE - Air Conditioning "How To" Books

CAPACITORS for HARD STARTING MOTORS
CAPILLARY TUBES
CLEANING & Legionella BACTERIA
CHINESE DRYWALL HAZARDS
COMBUSTION GASES & PARTICLE HAZARDS
COMPRESSOR & CONDENSING COIL, A/C
CONDENSATE HANDLING, A/C
CONDENSATION or SWEATING PIPES, TANKS
COOL OFF HEAT Thermostat Switch
COOLING CAPACITY, RATED
COOLING COIL or EVAPORATOR COIL
COOLING LOAD REDUCTION by ROOF VENTS
COMBUSTION GASES & PARTICLE HAZARDS
CONDENSATE HANDLING, A/C
CONDENSATION or SWEATING PIPES, TANKS

DATA TAGS on AIR CONDITIONERS
DEFINITION of Heating & Cooling Terms
DEHUMIDIFICATION PROBLEMS
DEW POINT CALCULATION for WALLS
DEW POINT TABLE - CONDENSATION POINT GUIDE
DIAGNOSE & FIX AIR CONDITIONER / HEAT PUMP
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DUCT SYSTEM & DUCT DEFECTS
DUCTS - Asbestos
DUCT INSULATION, Asbestos Paper
DUCT INSULATION for SOUNDPROOFING
DUCT SYSTEM NOISES
DUCTS, Asbestos Transite Pipe
DUST, HVAC CONTAMINATION STUDY
DUST SAMPLING PROCEDURE

EDUCATION, HVAC SCHOOLS
ELECTRIC MOTOR DIAGNOSTIC GUIDE
ELECTRIC MOTOR OVERLOAD RESET SWITCH
ELECTRICAL POWER SWITCH FOR HEAT
EVAPORATOR COIL or COOLING COIL
EVAPORATIVE COOLING SYSTEMS
EXPANSION VALVES, REFRIGERANT

FAN, AIR HANDLER BLOWER UNIT
FAN AUTO ON Thermostat Switch
FAN CONVECTOR HEATERS - HYDRONIC COILS
FAN LIMIT SWITCH
FAN NOISES
FURNACES WARM AIR HEATING SYSTEMS

GAS EXPOSURE EFFECTS, TOXIC
GAS DETECTION INSTRUMENTS
GAUGE, REFRIGERATION PRESSURE TEST

HEAT LOSS (or GAIN) in buildings
HEAT LOSS (or GAIN) INDICATORS
HEAT LOSS R U & K VALUE CALCULATION
HEAT PUMPS
HEATING SMALL LOADS
HOUSEWRAP AIR & VAPOR BARRIERS
HUMIDITY LEVEL TARGET

INDOOR AIR QUALITY IMPROVEMENT GUIDE

A/C INSPECTION CHECKLIST - OUTDOOR UNIT
A/C INSPECTION LIMITATIONS
LIGHT, GUIDE to FORENSIC USE
LOST COOLING CAPACITY
LOW VOLTAGE TRANSFORMER TEST

MANUALS & PARTS GUIDES - HVAC
MOTOR OVERLOAD RESET SWITCH
MOLD in AIR HANDLERS & DUCT WORK
MOLD INFORMATION CENTER

NOISE AIR CONDITIONER / HEAT PUMP
NOISE / SOUND DIAGNOSIS & CURE
  Air Leak Noises
  AIR CONDITIONING & HEAT PUMP NOISES

ODORS in AIR HANDLERS & DUCT WORK
OPERATING COST, AIR CONDITIONER
OPERATING DEFECTS, AIR CONDITIONING
OPERATING TEMPERATURES, AIR CONDITIONER

PORTABLE ROOM AIR CONDITIONERS
PRESSURE READINGS, REFRIGERANT

REFRIGERANTS & PIPING
REPAIR GUIDE, AIR CONDITIONERS / HEAT PUMPS
REPAIR & DIAGNOSTIC FAQs for A/C
RETROFIT SIZING for A/C or HEAT PUMPS

SEER RATINGS & OTHER DEFINITIONS
SYSTEM OPERATION
SWAMP COOLERS

THERMOSTATS, HEATING / COOLING
THERMOSTATIC EXPANSION VALVES

WATER COOLED AIR CONDITIONERS
WINDOW / WALL AIR CONDITIONERS
WINDOW / WALL A/C SUPPORTS

More Information

Photograph of  this unusual attic air conditioning system is an example of the range of human creativity observed during a career of building inspections Air Conditioning Inspection Limitations for Home Inspectors
     

This website answers most questions about air conditioning systems:

  • A/C INSPECTION LIMITATIONS - How to inspect air conditioning systems. What are the limitations on inspection of an air conditioning system?
  • A/C - HEAT PUMP CRITICAL DEFECTS - separate article
  • A/C INSPECTION CHECKLIST - OUTDOOR UNIT - separate article
  • DEFECTS LIST - AIR CONDITIONING - separate article
  • Questions & Answers about how to inspect air conditioners or heat pumps
  • References

Click to Show or Hide Related Topics

  • AIR CONDITIONING & HEAT PUMP SYSTEMS - home
  • A/C COMPONENTS
  • AIR FILTERS for HVAC SYSTEMS
  • AIR HANDLER / BLOWER UNITS
  • BACKUP HEAT for HEAT PUMPS
  • BTU CHART for AIR CONDITIONERS / HEAT PUMPS
  • CLEARANCE DISTANCE, HVAC
  • COMPRESSOR & CONDENSING COIL, A/C
  • CONDENSATE HANDLING, A/C
  • CONTROLS & SWITCHES, A/C - HEAT PUMP
  • CONDENSING COIL REPAIR REPLACE
  • COOL OFF HEAT THERMOSTAT SWITCH
  • COOLING CAPACITY, RATED
  • COOLING COIL or EVAPORATOR COIL
  • COOLING COIL CLEANING
  • DATA TAGS on AIR CONDITIONERS
  • DEHUMIDIFICATION PROBLEMS
  • DUCT SYSTEM & DUCT DEFECTS
  • DUCTLESS AIR CONDITIONERS & HEAT PUMPS
  • EDUCATION & CLASSES, HVAC SCHOOLS
  • ELECTRIC MOTOR DIAGNOSTIC GUIDE
  • EXPANSION VALVES, REFRIGERANT
  • FAN, AIR HANDLER BLOWER UNIT
  • FAN AUTO ON Thermostat Switch
  • FAN, COMPRESSOR/CONDENSER UNIT
  • FAN CONVECTOR HEATERS - HYDRONIC COILS
  • FROST BUILD-UP on AIR CONDITIONER COILS
  • GAUGE, REFRIGERATION PRESSURE TEST
  • HEAT PUMPS
  • HUMIDITY LEVEL TARGET
  • MANUALS & PARTS GUIDES - HVAC
  • MINI SPLIT AIR CONDITIONERS & HEAT PUMPS
  • NOISE AIR CONDITIONER / HEAT PUMP
  • ODORS in AIR HANDLERS & DUCT WORK
  • OPERATING TEMPERATURES
  • PORTABLE ROOM AIR CONDITIONERS
  • PRESSURE READINGS, REFRIGERANT
  • REFRIGERANTS & PIPING
  • REPAIR GUIDE - A/C or Heat Pumps
  • REPAIR TOPICS A/C & HEAT PUMPS
  • ROOFTOP A/C / HEAT PUMP
  • SEER RATINGS & OTHER DEFINITIONS
  • SPLIT SYSTEM Ductless Air Conditioners
  • SWAMP COOLERS
  • THERMOSTATS, HEATING / COOLING
  • THERMOSTATIC EXPANSION VALVES
  • WALL CONVECTORS Heating / Cooling
  • WINDOW / WALL AIR CONDITIONERS
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

The limitations of visual inspection of A/C systems are described here. This article series answers most questions about air conditioning systems. We describe how to inspect residential air conditioning systems (A/C systems) to inform home buyers, owners, and home inspectors of common cooling system defects.

The chapters a this website describe the basic components of an air conditioning system and then we discuss how to estimate the rated cooling capacity of an air conditioning system by examining various data tags and components. We continue to add to and update this text as new details are provided.

Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.

3. INSPECTION LIMITATIONS - Air Conditioning System Inspection Limitations

A home inspector is expected to at a minimum, perform a visual inspection of the cooling system and all of its visually accessible components, and to identify significant or dangerous defects. "Inspect" means "operate" or "turn on" if site conditions do not give the inspector a reason not to operate the equipment.

The ASHI, NAHI, CREIA, TAREI, FABI, CAHI, and other professional home inspection associations set inspection standards as do many U.S. states and Canadian provinces which license and regulate home inspectors. Home inspection standards generally do not require that equipment be disassembled, tested with instruments (amp probes, refrigerant gas detectors, coolant pressure measurements). In addition, the inspector is not expected to inspect any equipment, component, system, or area of a building if in the inspectors opinion that action is unsafe or is likely to cause costly damage.

"Non-central" air conditioners such as window units and "through wall" units (which are basically the same portable devices) are excluded from inspection by most standards. We would interpret ductless systems such as those shown at A/C TYPES, ENERGY SOURCES to be equipment that should be included in a home inspection as these are substantive, permanent systems and they operate using controls similar to ducted central air systems.

These limitations apply to home inspectors examining cooling systems and heat pumps, especially if the equipment appears to be in dangerous condition (damaged wiring for example), or is in a "shut down" or "seasonally shut down" condition, such as operating a cooling system during low temperature conditions.

While home inspectors may omit certain items from inspection under appropriate conditions, the inspector is still required to explain that omission to the client and, where appropriate, to offer follow-up advice.

Below are offered example home inspection report wording describing typical limitations on the ability of a home inspector to examine the condition of an air conditioning or heat pump system. [Contributions and critique are invited.]

COOLING SYSTEM INSPECTION LIMITATION: We check for normal temperature differential between input and output air, unusual operating noises, visible damage or defects, and a variety of other possible defects. This inspection is not technically exhaustive; a more thorough inspection, also not technically exhaustive, can be performed by a qualified HVAC service professional, and is recommended when any defects or malfunction are suspected.

Here are some examples of warning language we might use in a report. A system is not considered "not useable" simply because it was shut down, but if it was shut down, not operated, and by visual inspection, has visible major defects, we would go further to explain this condition, even though the system was not turned on. A home inspector who sees that a system is visibly damaged, missing components, or antiquated, but who uses the escape clause of "it was shut down and not inspected" to say nothing more to his/her client, is not doing the best job for the client.

Central Air Shut Down, Not Tested Due to Temperatures

As the cooling equipment had clearly been shut down and because the weather temperature in the past 24 hours has been below 65 degF. we were not able to test-operate this equipment. Operating cooling system equipment which has been "shut down" without proper preparation risks costly damage to the compressor or other components.

Note: some compressor motors can be seriously damaged by being "slugged" with liquid refrigerant or by lack of good lubrication if the compressor is started in cold conditions. Some air conditioner units, including heat pumps, are likely to have a heater band installed around the compressor motor to keep its temperature up to operating state in cold weather. If such a system using a motor heater has been left with power off for some time, simply turning it on in cool weather is not enough as the heater would need time to warm up the motor.

Central Air System Shut Down, Not Tested Due to Condition

The cooling system was shut off at the time of our inspection. By visual inspection we observed these conditions which suggest that the system should not be turned on before it is inspected and if necessary, repaired by an HVAC technician:

  • burned electrical wiring at the air conditioning system controls
  • open fans, a serious safety hazard
  • the building has a large area of visible mold - running the system risks distributing potentially allergenic or harmful particles throughout and also risks contaminating the HVAC system duct work and air handler
  • other:___

We recommend that you make no attempt to turn the air conditioning or heat pump system on before having it examined by a qualified air conditioning service person. If replacement of major components is required, repair is likely to involve a significant expense. Inspection and repair are needed before you can use the system.


Frequently Asked Questions (FAQs) about how to inspect air conditioning or heat pump systems

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Technical Reviewers & References

Related Topics, found near the top of this page suggest articles closely related to this one.

  • Thanks to AMark Cramer, Tampa Florida, for assistance in technical review of the "Critical Defects" section and for the photograph of the deteriorating gray Owens Corning flex duct in a hot attic. Mr. Cramer is a Florida home inspector and home inspection educator.
  • Thanks to Jon Bolton, an ASHI, FABI, and otherwise certified Florida home inspector who provided photos of failing Goodman gray flex duct in a hot attic.
  • Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment
    Special Offer
    : Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.

  • Thanks to Scott at SJM Inspect for suggesting this EPA document and for technical editing remarks regarding our air conditioning website, SJM Inspection Service LLC, serves the entire state of CT, sjminspect.com 203-543-0447 or 203-877-4774 5/16/07

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

  • Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
  • Home Reference Book - Carson DunlopThe Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.

    Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.

  • GO TO Carson Dunlop's Home Study Course Information - How to Become a Home Inspector: Carson Dunlop's nationally recognized Home Study Course, selected by ASHI the American Society of Home Inspectors and other professionals and associations. This website author is a contributor to this course.
  • GO TO Carson Dunlop's Home Study Course Information - How to Become a Home Inspector: Carson Dunlop's nationally recognized Home Study Course, selected by ASHI the American Society of Home Inspectors and other professionals and associations. This website author is a contributor to this course.
  • GO TO Carson Dunlop's Home Study Course Information - How to Become a Home Inspector: Carson Dunlop's nationally recognized Home Study Course, selected by ASHI the American Society of Home Inspectors and other professionals and associations. This website author is a contributor to this course.
    Building inspection education & report writing systems from Carson, Dunlop & Associates Ltd
  • Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment
    Special Offer
    : Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.

  • Complete List of Air Conditioning & Heat Pump Design, Inspection, Repair Books at the InspectAPedia Bookstore.
  • Modern Refrigeration and Air Conditioning, A. D. Althouse, C.H. Turnquist, A. Bracciano, Goodheart-Willcox Co., 1982
  • Principles of Refrigeration, R. Warren Marsh, C. Thomas Olivo, Delmar Publishers, 1979
  • "Air Conditioning & Refrigeration I & II", BOCES Education, Warren Hilliard (instructor), Poughkeepsie, New York, May - July 1982, [classroom notes from air conditioning and refrigeration maintenance and repair course attended by the website author]
  • Refrigeration and Air Conditioning Technology, 5th Ed., William C. Whitman, William M. Johnson, John Tomczyk, Cengage Learning, 2005, ISBN 1401837654, 9781401837655 1324 pages
  • NewAir Conditioning SEER - New DOE Air Conditioner and Heat Pump Efficiency Standard
  • Asbestos HVAC Ducts and Flues field identification photos and guide
  • Fiberglass: Indoor Air Quality Investigations: Fiberglass in Indoor Air, HVAC ducts, and Building Insulation
  • ...

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