Freezing back to comp (mitsu elec)

[charlie]

Have a look to the zep industries web site (there is one for France too) the product you are looking for is the "Foaming Coil Cleaner".

[The Viking]

Have a look to the zep industries web site (there is one for France too) the product you are looking for is the "Foaming Coil Cleaner".

Isn't this the cleaner that's really corrosive and need to be well rinsed after use? Also if we are talking about the same cleaner then it's for condensors only.

[expat]

Gary you are of course right as you would be (after all you did write the book) and I would have to add that I didn't immediately notice this problem several months ago when doing the inspection because I acted like a complete novice and started by hooking up the gages instead of using common sense and the other five senses.

I've often read with interest your posts where you stated the importance of air flow and I could not believe that it would make such a difference with only a minor restriction. I mean I could feel air flowing on fan full speed but it felt more like low speed.

I still find it surprising that so much muck was able to get through those tiny spaces between the fins of the evaporator and adhere to the fan.

Oh Viking, I don't think Charlie gets my point here as I'm looking for a preventative cure but hey if anyone can think of an easier way of cleaning them rather than completely dismantling I'm all ears.

Good to hear from you all.

[Brian_UK]

<->I still find it surprising that so much muck was able to get through those tiny spaces between the fins of the evaporator and adhere to the fan.<->.

Unless I'm mistaken the air passes through the filter then the fan blows it out through the coil.

As has been said above, a clean filter is the most important part of the system. This assumes before the filter is removed for cleaning that the fan has been turned off.

The number of times I have seen blocked filter pulled out of a unit with the fan running is scary.

In a normally running unit some of the dust will pass through or around the filter. Providing there is some condensate being produced then, with luck, the dust will run off into the drain tray and get pumped away.

If the dust is allowed to get too heavy then whenever the unit stops producing moisture (off period) but the dust is still being drawn in and will start to collect on the outlet of the coil.

This little collection of dried dirt will slowly buildup like a small dam on the fins and as the airflow reduces then more dust can settle out.

If the units are heat pumps then a quick run in heat mode and the use of your nose can indicate potential blockage problems.

If it smells rank then there is muck on the coil which is getting cooked with the higher temperatures.

[Makeit go Right]

I've seen a 6-month old 5kW system with caked up fan scroll. The filter did its best, then the dirt got around the filter, filled the coil and caked onto the fan impellor blades. The convenience store manager liked to leave the front door open and the speeding traffic outside created lots of dust, which found its way into the open store and was then drawn into the unit.

The manager, who insisted on doing his own filter cleaning with just an annual service from us, was shown how to clean the filters and told to check every 2 weeks. But he had done nothing until the unit duty dropped off. Then he opened the front and hoovered the filters in situ, and then called us to complain about poor performance of the unit (under warranty).

The fan impellors were rotating nicely but they were so clogged that the curved blades were just like round rods, with no affect on moving the air through the unit.

The filters were clean in the middle (where he had hoovered) and completely choc-a-block at the edges. "Exibit-A." Well, the unit needed major surgery to clean it up properly, and the manager paid the repair bill.

I called in 3 weeks later and checked that he was cleaning it correctly - he was.

Six-month intevals and even 3-month intevals are sometimes not frequent enough, like in the above example. So, if you have an open door or otherwise dirty environment, be sure to show the customer how to clean the filters and tell him/her to clean frequently until the correct frequency is evident. That way s/he cannot say "Well I didn't know they needed cleaning so often."

[charlie]

Viking,

You are right I haven't read carefully the message, my fault.

From what I know the product is specific for split and fan coils (so indoor coils) and defnitively isn't aggressive for the aluminium fins.