A new article for home inspectors, “How to Inspect the Refrigerator,” has been added to InterNACHI’s Library of Inspection Articles.
Library is at http://www.nachi.org/articles.htm
Ben in your narrative you give the impression that the expansion valve is what creates the mist in the evap. That is not correct the metering device (Cap Tube) simple creates a pressure differential between the high pressure side and the low pressure side of the enclosed loop, the refrigerant becomes a vapor due to a pressure drop within the evap not because it is forced thru a metering device.
Just trying to be helpful
Updated the article with new content about the refrigerant control: www.nachi.org/how-to-inspect-refrigerator-appliance.htm
Thanks Charley.
Out here refrigerators are considered personal property, similar to the washer and dryer, televisions, etc., so we don’t inspect them.
Very good Ben after the correction from Charley. I had fun explaining this in the Class.
Heaven forbid KW did I understand you correct to say you taught a refrigerant class.
Ok here is a test question and its not a trick question
There are four types of refrigerant metering devices name them and I will give you two to start you off.
- TXV (thermostatic expansion valve)
- Capillary tube (Cap Tube)
3.XXXXXXX - XXXXXXX
Go for it Big boy name them and Google will be of no help:roll:
Charley writes:
I believe there are actually eight, but I can only name 5 off the top of my head. But there are eight.
!!Name 5 then ???:p;-) in all actually there is probably more than 8 if one gets into all the different type of refrigerants, trying to be easy on KW the Pope has raked him over the coals
While refrigerators are up, how about cleaning out the freezer once in a while. T:vomit:hem there food scraps are clogging up drains down this here way !
Electronic expansion valve
Thermostatic expansion valve
Automatic expansion valve
Adjustable hand expansion valve
Highside float valve
Lowside float valve
Accumulator for a fixed orifice system
Missing one (maybe more). Anyway, nothing a home inspector will ever have to know about or deal with.
Ya cheated ya went on google Accumulator and fixed orifices are two separate items, the accumulator is down stream of the evap the fixed orifice is on the inlet to the evap;-)
Long time back I did need to have this knowledge but again it was just basic for ODS Ozone depleting substances badge. Speaking of which I need to go this year for the renewal course.
Charley… Carson Dunlop Certificate provided the basics but still pretty good for HI’s, so your comment that I taught a refrigerant class is wrong as there is much more to that.
I don’t see how a fixed orifice system is a metering device, but I’ll defer to you on that Charley.
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Great info on TEV even though most documents call it the TXV.
here is one.
http://vts.inxpo.com/scripts/Server.nxp?LASCmd=AI:4;F:QS!10100&ShowKey=18680&AffiliateData=circ
Fixed is somewhat misleading because its not fixed as one would think its a small piston type cylinder with a fixed sized orifice drilled thru it different size holes for different tonnage. it just slips inside a brass type fitting just before the entrance into the A-coil (evap) the novice would not even know what it was by just looking at it. Some might think it was just a flared fitting the system will not operate without it you would flood the evap with liquid refrigerant which would be carried back to the compressor and wash the oil from the compressor. That would be 10X worst than operating a A/C unit with the exterior ambient at 25 degrees:shock:
Gone
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