Driers???

[daddymac]

Hi All!

I've been removing a number of defunkt IMI condensing units off our plant roof and I note with interest that they are all fitted with in-line filter/driers! Admittedly, these are R22 cooling only systems and not heat pumps, but I am wondering why driers are rare on newer installs. Obviously, you'd need a bi-flow for a heat-pump, but given that "cleanliness is next to Godliness" in the refrigeration game, would fitting driers to my future installs be a good idea!
Your thoughts??

DM

[PoodleHeadMikey]

DM,

Liqu8id line filter-driers are standard items in any built up (non-packaged) system that we install. Isn't that the basic 'standard of the industry' where you are?

They are cheap and 'cheap insurance' against anything getting to the TXV. Why Wouldn't you install them would be the better question?

[paul_h]

Well the practice of not putting driers in modern day splits started when they started putting the capillary/txv in the outdoor unit. It doesn't make much sense to add a drier "for insurance against anything getting to the TXV" when any dirt/moisture in the system would have blocked the TX before the drier anyway, as you can only put the drier after the flow control device.
The manfacturers seemed OK with no drier in the system, they've been manufacturing through the wall style RACs for ages without driers, and if your joins are OK and the lines properly evacuated there shouldn't be a problem.
That said, for any unit with the TX in the indoor, we still put in a drier, and for any compressor change, we add a drier. But we don't put in a drier for any new properly done installs, as manufacturers install instructions don't state you need one (edit: and as said before, any drier you install wil be after the TXV/capillary anyway).

[daddymac]

Cheers Paul... I forgot that the TRV is now in the outdoor unit on most split A/C units.
ATB
DM!