Thread: Miss match compessor & coil

Has anybody found this problem 5 ton compressor and four ton coil.
That doesn't work. and after replacing the coil to a five ton did it solve the problem?

Similar Threads:

• "Shrink-swell soil" article. Did inspector miss this?
• Could MIKE HOLMES miss P trap & vent so easely?
• Could MIKE HOLMES miss P trap & vent so easely?
• got a match?
• Dryer Vent Next To Condensing Coil

Originally Posted by Art McKenna

Has anybody found this problem 5 ton compressor and four ton coil.
That doesn't work. and after replacing the coil to a five ton did it solve the problem?

That is backwards...

It is fairly common to see an upsize in the evaporator over the condenser but not the other way.

If this is a new system, chances are that the manufacture will not allow it in their specs.

It can be done, perhaps sometimes successfully. Ask your dealer for the AHRI reference number, certificate of match.

The house I purchased for myself this last year has a 2.5 ton compressor and the evaporator is only 2 ton. I inspected the home and reported the AC worked correctly. temp slit was 20 degrees. I never crossed referenced the two and had no idea. After moving in I found that when the AC is operated for several hours, The evaporator completely ices up and no longer works. My wife says we should sue the home inspector

Originally Posted by Bill Anglin

The house I purchased for myself this last year has a 2.5 ton compressor and the evaporator is only 2 ton. I inspected the home and reported the AC worked correctly. temp slit was 20 degrees. I never crossed referenced the two and had no idea. After moving in I found that when the AC is operated for several hours, The evaporator completely ices up and no longer works. My wife says we should sue the home inspector

Though it is backward as Scott said, you may be able to remedy it by having a TXV valve installed.

Originally Posted by Vern Heiler

Though it is backward as Scott said, you may be able to remedy it by having a TXV valve installed.

Or bumping up the air flow if possible. Higher speed tap on the blower or reducing restrictions on the duct and filters may give you just enough to keep it above 32.

What is a TXV valve? Is that an expensive part and exactly what would that do to prevent the icing on the evaporator?

No We are replacing coil with five ton do yoy think this will this solve the problem? Bob did you replace coil and did it fix the problem?

Originally Posted by Bill Anglin

What is a TXV valve? Is that an expensive part and exactly what would that do to prevent the icing on the evaporator?

A TXV "Thermal Expansion Valve" is an active metering device used in place of a fixed orifice metering device. The TXV measures the temperature of the end of the evaporator coil and adjust the amount of refrigerant metered into the coil. They are not that expensive to buy, somewhere around $100. Putting them in is not all that hard but will add to cost depending on what kind of friends you have.

Art,
There are several questions you must have answered before you can arrive at an answer to resolving the equipment miss mach.
If you just install a matched coil you system it may not work.

1) Was the comp/coil sized to your house by a Manual J ?
2) What system size were your ducts sized for ?
3) Was your system designed for an AC split system or a Heat Pump ?
4) Is your air handler capable to handle the air flow requirements of the system?

There are more but that is a basic start to begin to determine what can or can not be done.
Your question is more complicated than you may want to believe.
Bring in a competent HVAC person and have him evaluate your entire system including the ducts and also do the Heat Loss Analysis (Manual-J).

The underlying question may be why was the 5 T comp installed?
Also, if the installer made a mistake in the equipment, what else did they do wrong ?