Frequently Asked Questions (and answers) about air conditioners & heat pumps

FAQs about air conditioning and heat pump systems help diagnose inspection, installation, troubleshooting or repair problems.

These FAQs are part of an article series discussing how to inspect and repair all types of residential air conditioning systems (A/C systems).

Air Conditioning & Heat Pump FAQs #2

These questions & answers about air conditioning & heat pump systems were posted originally

at AIR CONDITIONING & HEAT PUMP SYSTEMS - home

Heat pump schematic shown here provided courtesy of Carson Dunlop Associates, a Toronto home inspection, education & report writing tool company [ carsondunlop.com ]. [Click to enlarge any image]

Older Air Conditioning & Heat Pump Questions & Answers Posted Originally at aircond1123.htm

Can I use compressed air to un-clog AC piping?

My air-con unit works say 1 in 3 times is it possible there is a restriction in the supply pipe or water maybe as the unit was not used from new for about 5 years ?

I thought about removing the pipes and clear with high pressure air line. When it is working it is perfect. On 2013-03-28 by Neil Allen

Answer by (mod) -

Neil,

I'm not sure what water supply has to do with your air conditioner unless you're using a water-cooled system. Can you be more clear?

But certainly if your system is using refrigerant piping and a refrigerant charge you would not use compressed air to try to un-clog it; you'd have to remove the refrigerant and pull a vacuum on the system.

Water flow noise when the HVAC system is off in the fan-coil unit of the bedroom.

I have a constant water flow noise when the HVAC system is off in the fan-coil unit of the bedroom.

The builder made inspection on my request."It is our opinion that the noise level was not excessive and it falls within acceptable levels."

What are acceptable levels? My condominium unit is fitted with a vertical heat pump for the HVAC. Only my unit has this very anoing noise. Please help me, I can not sleep in my bedroom... On 2012-11-20 by PennyK

Suggestions by (mod) - track down and stop annoying air conditioner water flow noise

Penny,

The builder's opinion seems to have ignored a more appropriate approach - call an HVAC service tech to diagnose the system.

When we know the cause of the noises we can understand the need for a repair. When a mechanical system is supposed to beoff we dint expect it to make sounds.

Can we just top off refrigerant and tighten the flare fittings?

Can the system simply be topped up or does it need to be completely
recovered & re-filled with virgin refrigerant?

If a leak is found at a flaired joint, and is resolved by tightening? On 2012-09-12 by Mal

Answer by (mod) -

Mel,

Your service technican could add refrigerant without first evacuating the system in many designs, but for some equipment such ad a non- commercial refrigerator or freezer in which there is no receiver and the exact refrigerant charge amount is critical, topping up is not a reliable repair.

Watch out: you should not see flare connections in HVAC refrigeration lines as such joints are not reliable for that use.

...

Continue reading at DIAGNOSTIC GUIDE A/C or HEAT PUMP or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see AIR CONDITIONER HEAT PUMP FAQs-3 - more Q&A on AC troubleshooting

Or see these

Recommended Articles

• AIR CONDITIONING & HEAT PUMP SYSTEMS - home
• AIR HANDLER / BLOWER UNITS - home
• COMPRESSOR / CONDENSER REPAIR - home

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AIR CONDITIONER / HEAT PUMP REPAIR FAQs-2 provided free at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to AIR CONDITIONING & HEAT PUMPS

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