Factory installed LL dryer

DuMass

Why do some manufactures insist on factory installing a LL dryer inside their condenser units?
Is this an attempt to make installation easier for DIY or are they truly concerned that a competent installer would somehow forget to actually use one. Seems silly to me.
Would you ever really consider not using a LL dryer on one of your installs?

nicktech

i guess it could justify a higher cost, or it ensures that any schmuck putting it in incorporates a LLD

milk man

Because the installers where not installing them.

evapman

Have ran into a few with 2, one factory installed in cabinet, 1 outside tech installed. double the fun I guess

milk man

Lennox's policy as told to us in a class was to install a second drier for all low side repairs where gas can be pumped back into the CU. (R410a).

Remove the factory drier and stub to space with high side repairs, or if system is flat. Add drier outside of cabinet. Again we are are talking about R-410a systems.

jvegas

I have seen some installers that don't install a dryer not sure of the reason

JohnH1

You really should not need a dryer other than the factory installed one if the system is clean and dry. It is just another restriction in the curcuit.
I was once told even in a compressor burn out situation you may need to change the dryer out a couple of times but once the system is cleaned up and no more acid to remove the dryer. Although I would still leave the factory dryer in place.

milk man

All 410a machines need liquid line filter driers because evacuation will not boil out water from the POE oil.

jvegas

Thanks for the info but where does this come from manufacture or experence

hvaclover

ICP, Nordyne and many more do not come with driers. To say they are just another restriction is ignorance. All driers are much larger than the pipe they being installed on..

__________________
Not Stupid, Just slow

milk man

Manufacture.

One had a power point slide that showed little tiny animated bubbles. They could not break through the oil film on top of the oil.

beenthere

Probably 80% plus of all units installed wouldn't have a LLFD if the factory didn't install one.

By installing one themselves. They reduce compressor failures. From those companies/installers that would be too cheap and or lazy to install one themselves.

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How many times must one fix something before it is fixed?

hvaclover

The only mfg who installs a LLD of significant size even worth mentioning

Armstrong. And maybe ICP. But the rest of them are tool small to make it worth while for my money.


I don't use equipment with the undersized LLD, but if we did we would put a 16cu in right at the evap as a routine matter.

__________________
Not Stupid, Just slow

mechanicalDvr

I would never leave any drier in place that was in the system prior to a burnout, that's just asking for problems.

mechanicalDvr

All the literature on 410A systems. Pulling a vacuum will not remove all moisture from POE oil, ever.

mechanicalDvr

Are you talking just residential condensing units or RTUs as well? I see plenty of Trane and other RTUs with full size filter driers all the time.

DuMass

I find this alarming. It’s disturbing to know that there are so many hack installers out there with no skills or conscience.

beenthere

Lots of companies cut corners where ever they can. To make up for their low bids.

Lots of companies don't provide service agreements. And then get to make more money coming out to make repairs a few years later that they get to charge for. Because the unit held up long enough to make it through the labor warranty.

Compressor manufacturers are demanding that the FDs be installed at the factory in order to get the longer warranty.
Because they have seen the failures from poor install practices.

Many low priced companies, can't afford to send their techs to training classes. So those techs don't learn proper practices.
And end up walking around saying" I never heard of that".

__________________
How many times must one fix something before it is fixed?

RoBoTeq

When I was a Regional Technical Service Manager for Gooman Manufacturing I constantly fought the internally installed filter/drier, to no avail. When Goodman started putting the filter/drier in the Amana brand units as well, I knew it was a lost cause to keep them out. Turns out that in order to get a better warranty from Copeland, Copeland required the units to have an internal F/D installed.

When you think about the massive amounts of units that are installed by piece workers in track homes and multi-family buildings it becomes easier to understand that most filter/driers provided with units never get installed.

I am with Lennox on their proceedure for filter/driers when work is done on sytems that requires opening up the refrigerant system. Other then poor installation practices, the most contaminants that get into systems get there from gauge hoses not being purged properly.

JohnH1

Agreed. I ment after the system was cleaned up I would install a new factory dryer and leave in place and the burn out dryers would be removed.