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Photograph of  This new compressor was placed directly against
a brick wall. One third of its condenser coil cooling ability was blocked.Air Conditioning & Heat Pump System Life
Factors that determine the life of air conditioning & heating equipment

Air conditioner or heat pump life:

This article describes the key factors that influence how long an air conditioner or heat pump can be expected to last - its life expectancy. Some of these factors also affect the life expectancy of heating furnaces, boilers, and other HVACR equipment too. We include citatations of research on HVAC system component life expectancy and standards for measauring or estimating that data. We include links to related articles on how to determine the age of heating & cooling equipment, furnaces, boilers, heat exchangers.

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- Daniel Friedman, Publisher/Editor/Author - See WHO ARE WE?

What is the Average Life of an Air Conditioning or Heat Pump Compressor ?

Air conditioning compressors overgrown with shrubs (C) Daniel Friedman

[Click to enlarge any image] Just how long should an air conditioning or heat pump compressor unit or motor last? There is not a single right answer. The typical life of an A/C compressor ranges from 10-20 years.

As you can see in Carson Dunlop Associates ' sketch at left the life of an air conditioner outdoor compressor/condenser unit depends on the climate in which it is located. .

The air conditioner compressor, condenser, fan unit is the "outdoor" half of an air conditioning or heat pump installation that uses a compressor motor to compress refrigerant gas to high pressure, sending the pressurized gas through cooling coils (condensing coils) where aided by air movement drawn by the condenser unit fan, the gas is returned to a liquid refrigerant state.

The process of compressing and then condensing the refrigerant back from a gas to a liquid also moves heat out of the refrigerant and into outdoor air. We explain this process in detail

at COMPRESSOR / CONDENSER OPERATION - how it works to heat or cool a building

The outdoor half of a typical air conditioning system (shown here) is a unit containing the refrigerant compressor and condensing coil and a cooling fan. In our photo the gray screened area covering one side of the condensing coil of the first compressor in this row is easily visible.

The compressor motor itself (below-right) is not visible unless the covers of this unit are removed.

Factors Affecting the Life Expectancy of Air Conditioners & Heat Pumps

Air conditioning compressors overgrown with shrubs (C) Daniel Friedman

Research on HVACR System Life Expectancy

Question: Is the problem with the fan motor or the compressor motor in my condenser unit?

I've a Lennox outside a/c unit. The fan/motor and compressor are part of the unit. The fan was not spinning and the A/c is not running. I've isolated the problem down to the fan/motor or the compressor, but don't know how to check or find out which it is. Any idea on how to check if the fan/motor is 'bad' or the compressor is 'bad'? - Fan or ... 7/23/11

Reply:

Fan or compressor: you could also have a bad control board, or relay switch in the compressor/condenser unit.

If the fan is bad and the compressor is OK you'll hear the compressor turn on at the start of a cooling cycle, though a bad fan and system overheating could later cause some compressors to turn themselves back off. Similarly, if the compressor is bad your fan motor would still run. So I'm suspecting a control or switch problem./

Question: Icing at the compressor; compressor not turning on?

the outside unit of the heat pump is icing up on the compressor - Steve 8/7/11

Hi my fan in my house goes on but my compressor unit does not all the electric seems to be fine . could it be my thermostat? - Sam 8/7/11

the accu very heat,although it is new gen. clean,2Tr LS-60psi & HS-100psi, - Anon 8/6/11

Reply:

Steve: icing at the compressor/condenser sounds like a refrigerant charger or refrigerant metering problem.

Sam: if your thermostat turns on the air handler but the compressor/condenser does not run, the problem is not the thermostat. Check out the diagnostic suggestiosn beginning at LOST COOLING CAPACITY (link at the ARTICLE INDEX the bottom of this article )

Anon: those pressures look kind of low, no? What does your HVAC tech say about normal for that system?

Question: My A/C compressor just won't stop running

I recently noticed my AC condenser unit still running when the system inside shutoff by itself. and also, does the condenser unit have to be leveled. I notice the slap which holding the unit is slopping. Any suggestions? Thank you. - Rick 8/16/11

Reply:

A/C compressor/condenser won't stop running:

Rick usually when an A/C condenser unit won't stop running even though the inside equipment has shut off by itself my thinking divides into two investigations:

- is there a problem with the INDOOR unit such as a blower fan that won't start, an access door switch open, a condensate drain switch turning off the blower unit - these can leave the system calling for heat and the compressor running (though that's not good for the compressor)

- is there a problem with the outdoor equipment such as a bad control relay or control board

Question: loud cricket chirping sounds at the compressor/condenser unit, and slow starting

outside unit making loud cricket sounding noise when running. Takes long time to come on when temp set low. - JT 7/276/12

Reply:

JT our link at the ARTICLE INDEX the bottom of this article NOISE AIR CONDITIONER / HEAT PUMP provides noise diagnostics.

About taking a long time for the A/C to "come on" when the temperature is set low: the thermostat is operating like an "on-off" switch that turns the air conditioner system on and off in response to room temperature. It's not an accelerator. So if there is an operating problem related to the system controls, the number of degrees below the room temperature to which the thermostat is set should make no difference in how long it takes the A/C system to start. As long as the SET temperature is lower than the room temperature the cooling system will turn on.

Question: how long should the AC run when first turned on

Anon said

when you turn on the AC for the first day of summer or heat how long would the unit circulate air then when does it stop

Reply:

The length of time that the A/C will run depends on many factors including

- the thermostat set temperature

- the building temperature at time the A/C is tuned on

- the efficiency of and cooling power (BTUS) of the system

- where the air is delivered

- thermostat location

- the thermal mass of the building: what materials have been heated up and need to be cooled down

- the heat gain rate of the building

- outdoor temperature, wind, and sun exposure

The air will circulate and the A/C will run until the thermostat is satisified. If the system cannot satisfy the thermostat for any reason the system will keep running.

Question: water at the base of the compressor

(June 30, 2014) Anonymous said:

Is it normal for there to be water coming out of the base of my compressor

Reply:

Anon

Water at the outdoor compressor condenser is probably coming from melting ice or frost. If you see cycles of significant ice or frost build-up the refrigerant charge or metering may be incorrect and I'd ask for a check by an HVAC tech.

Question: Compressor won't start

(July 13, 2014) Anonymous said:
i have a Carrier heat pump that i cant get the blower to come on. I have replaced the board and thermostat and not sure what to do next. Any suggestions?

(Aug 2, 2014) Lou said:
I have a carrier condensing unit that the compressor wont start.I have voltage at the contactor and have replaced the start cap and run cap.odd to say,im drawing 11 amps on start and run wires coming from the contactor but i hear nothing from the compressor! any suggestions?

Reply:

Lou

Check for a bad start relay

Question: compressor won't run until it's cooled down

(Aug 14, 2014) Andre Matthew said:
my AC is not cooling well don't know the problem with that.

(Aug 21, 2014) Wayne said:
When unit is cold it will start and run. After an hour the cooling fan stops but the compressor continues for a short time then quits. It will continue to start but will not start and run until it cools down.
Any ideas?

Reply:

Look for an overheating fan motor, relay or control board or possibly a refrigerant metering valve that is sticking.


...

Continue reading at AGE of AIR CONDITIONERS & HEAT PUMPS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

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