Ice buildup, why...

[Haubeil]

What would cause ice to form on the AC lines? What should I recommend to my clients?

The ice is not only outside (shown in Picture 15) but inside as well as well (see Picture 49). I can assume the evaporator is one big ice cube!

Thanks,

Haubeil

Download Attachment: Picture 015.jpg

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Download Attachment: Picture 049.jpg

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[chrisprickett]

Two common causes are low refrigerant (maybe a coolant leak?) and a dirty coil. Running it in this condition can damage the compressor. Recommend repair by a licensed HVAC contractor.

[gwharton1]

Chris is dead on. The most common cause (90% chance) is a blown collant load. There is little to no coolant remaining in the system. Recommend to the buyer that he has the system checked immediatly.

Better yet, if the seller or seller's agent is around, recommend thay have the system checked today . Running the system under these conditions can damage it. They are also really running up their electrical bill. Assumiong closing is a month or so out, it will benifit the seller to handle it ASAP. That saves your buyer $s also. The seller can show the buyer a paid invoice from a licensed technician and all is well.

Glenn

[BlackJack]

It is very bad to run a unit in this condition. Air cannot circulate thru the coils, so it is forced thru every nook and crannies into the hot attic spaces. It condenses in the hot attic area. It will need to be resealed. It is also bad for the compressor. Low refrigerant is the #1 cause, but can be caused by other things. Low refrigerant indications usually are seen with the evaporator coils freezing up. You usually don’t see it backed up to the compressor as in your picture that often. It could also be caused by a bad compressor, high refrigerant levels, too small an orifice or expansion valve problem , coils clogged, or air leaks in the air return.

In your picture, the ice seems to be starting at the expansion valve. So that could be it. Looks like a York Unit.

[Terence McCann]

As others have said, refrigerant leak, dirty air filter, dirty evap coil, fan running on low speed, too many registers shut, blocked return air, etc.

This will kill an older style compressor, the new screw compressors are more forgiving.

Bottomline is to punt and call in a HVAC tech.

[Haubeil]

Thanks fellows!!

- Haubeil

[Chad Fabry]

I've never heard of screw compressors on AC units. I'm familiar with scroll and piston types for AC and I had a screw compressor in my shop so I guesss I'm pretty familiar with the Roots style as well, I just haven't seen them used with AC. What brands are using them?

[Terence McCann]

Meant to say scroll compressor Chad. They do however make screw compressors for large tonnage chillers. Trane, York, McQuay and Carrier make them. Google has a bunch of info.

[MelB]

I have seen this three times this year. Each one had the icing at the compressor and running inside. All three were caused by a (very) dirty air filter. Hope this helps...

[dandersen]

Low refrigerant will cause the coil to freeze (over a period of time). It will not freeze out to the condenser though.

The cause of this is restricted air flow or a TXV that is stuck open (not likely).

Start at the filter and work back to the air handler.