filter dryer changing?

[kurt s]

i had a guy giggle and tell me i was crazy because i didnt change filter on a large 50 ton R22 system every year. I was always under the impression not to change filter/dryer unless you opened the system for repaire.

i havent been to school for a long time, maybe they teach something new now? or maybe i slept through that part of the class, it was over 10 years ago so i may have forgot ???

[sedgy]

hi kirt,
well I agree with you , that is unless you have a moisture prob , or an acid oil prob ,
carry on as you are = sedgy ,

[Magoo]

Be pro-active and change driers annually, why wait for a problem to develop and sell the recovery costs to client, who is going to look like and incompetent idiot. I have enough hassles now without creating more down the track.
magoo

[Sandro Baptista]

If the moisture sight glass is green; if the filter is clean » no significant pressure loss is created » the liquid temperature after the filter is the same (no liquid expansion) Why change the filter drier?...unless of course the system be open.

[750 Valve]

I see no compelling reasons to go changing them for the sake of it

[SeanB]

Changing them annually in a working system with no moisture, no leaks and no other oil issues is not needed. You might do it every 5 years along with changing the compressor oil though. Most systems have no drier, no oil changes and operate for many years ( unless made down to a price point and using cheap copper pipe and fins) with no problems.

[mark957]

hello
I agree with colleghiche precede me, I think that changing a filter for no reason is a waste of energy and money ........... only advantage is to provide work to the disadvantage of the client.

[jakabus]

I agree with magoo... better to be safe then sorry. A small yearly fee or a potetionaly expensive repair?

[jdunc2301]

I agree with magoo... better to be safe then sorry. A small yearly fee or a potetionaly expensive repair?

Agreed, but the cost of things is just going up and up, the accountants cheque book getting tighter!

[Grizzly]

Hi Kurt.

My answer to your question, contains all of the above.
Simply put the frequency of filter change depends upon several factors.

The first to consider is the type of filter fitted, meaning if it's the solid core type which has the bolted end-plate.
Are usually the type that are more frequently changed not least because of the size of system they relate to.
Yes historically they were changed every year and still should be if the comps are being serviced at the same time.
If the system in question is not disturbed and has no filter related issues.
Then provided there is no discernible temp diff across them.
I look for the temp diff across them to be in low single figures when you get to say a 4 to 6c split.type then they definitely need replacing.
Others say any temperature diff across the filter then they should be replaced.

What a lot of the guys are saying which makes absolute sense, with the smaller systems that have the brazed in-line liquid filters.
They rarely ever need changing which is true. Sometimes you only end up changing them because their rusty bodies are giving concern!
In fairness the larger the system the more likely the liquid line filters will need more frequent changing.
When you get to industrial sized plant then a regular maintenance schedule makes most sense.

At 50T duty it's all down to your site knowledge of usage and issues.
To make decision as to what option to take.
Just remember prevention is better than Cure!
Grizzly