Cleaning Carrier Evaporator


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Old 12-21-11, 01:46 PM
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Cleaning Carrier Evaporator

I have a Carrier Air Conditioner Model 38L4H419A1 in my attic which is connected to a horizontally installed Goodman gas furnace Model GMP 100-4. The unit is running fine however the evaporator has not been cleaned since I bought the house 5 years ago. Have had trouble finding a parts manual or any info on this unit. The duct work is all neatly wrapped and taped, so I would like to do as little damage as possible tearing into unit to get at the evaporator. Can anyone help with manual source or info ??
Cheers,
Hothouse
 
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Old 12-21-11, 06:38 PM
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Is this a case coil? Are just a coil attached to AHU?
 
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Old 12-22-11, 03:31 AM
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If you use a good filter and change it regularly, the coil should stay clean indefinitely.

Coil cleaning is not part of normal maintenance.

Symptoms of very dirty coil: Freezing up in cooling mode, poor airflow, poor performance, furnace high limit switch tripping.
 
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Old 12-22-11, 09:37 AM
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Carrier diagram

Thanks for the reply. Would still like to get at evaporator even though not having any problems at this time. Need a parts manual or some sort of diagram of unit. Don't know what a case coil is, or AHV. Sorry. Unit is as described in first post.
The outside unit has a date on it of 1992. So would think inside unit installed at same time and after 20 years should be inspected.
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Old 12-22-11, 02:20 PM
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OMG. Coil cleaning is part of a normal service. This is bad advice. Evaporators should be cleaned once a year
 
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Old 12-22-11, 03:02 PM
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I beg to differ airman (no Pro...just an opinion). At my last house in VA, the first time I opened it up was at least 5-6 years after I bought it. I was new to DIY and being a homeowner. I was out of the place for almost 3 yrs but ensured that the filters were changed monthly while it was rented. Typical fiberglass el-cheapo filters for the most part. When I did open it the coil was almost spotless. Even after vacuuming and spraying the cleaner and rinsing there was very little residue found in the vac or the bucket under the drain line. There was more collected dust and junk in the secondary drain pan than what I got out of the coil area. (Of course I did find that they had installed the coil BACKWARDS, there was a 1"x24" gap where they hadn't sealed the coil housing to the furnace, and the drain line was incorrect. So much for that company being Pros.)

The key, I think, was a tight fitting filter housing and regular replacement of the filters.

I think the evap coil should be CHECKED as part of the maintenance...and absolutely the condenser coil should be cleaned each year...but if the evap coil isn't dirty...why mess with it?

I firmly believe that most of the system check-ups done by many companies (not all, by any means) is just sucking money out of a persons pocket. Now...if they are not able or willing to DIY it..maybe. But if the check-up doesn't include temp checks of the input and output air, measuring the temps and pressures on the lines and similar (you know...a REAL check-up).....why spend $100 for someone to clean the coils and ask how it's working? Even then, just like car A/C, simply hooking up the lines to a system can cause the valves to start leaking and require a service call a week later.

Don't get me wrong...I'm not arguing or denigrating the trade....but a complete system check just isn't needed (IMO) if it's operating correctly. A lot of that depends on the homeowner being aware of how the system has performed in the past and how it is operating now, as well as them doing the basics of filter changes.
 
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Old 12-22-11, 11:10 PM
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Some info! Just 1/100 of an inch of dirt can reduce efficiency by 7 percent. I agree filters should fit tightly but they should be a proper merv rating as well. Remember a new filter is less efficient than a old filter. Servicing a unit should include all those things plus checking safeties and checking amp draw. Let's not forget that a service is to make sure unit is running at top performance plus to catch a break down before it happens. I use a merv 11 filter in my unit and on inspection the coil looks clean. But cleaning it does remove dirt from the coil. Remember that coil is a inch plus thick and most of the dirt is trapped between the fins
 
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Old 12-26-11, 05:38 AM
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Interesting Info But

Interesting information but still don't have a source for diagram of unit. Can anyone help????
Cheers,
Hothouse
 
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Old 12-26-11, 09:19 PM
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typically there is no manual for what you want to do. You take the door off and a bunch of screws and pull the coil out if possible (depends on your line set and location) and clean the coil. Very doubtful you will find a manual. A picture MIGHT help us to understand your setup.
 
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Old 12-29-11, 09:45 PM
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I don't think that this is a Carrier model number.
If this is a horizontal slab coil with a transition (duct section), you may be able to clean it in place.



If it is an A coil, you may regret any attempt to clean this yourself.
 
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Old 12-29-11, 09:58 PM
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If you see anything like this you probably have a return air leak...

 
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Old 01-01-12, 07:08 AM
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Photo problems

Sorry for the delay in posting. Having trouble getting photos onto this web site.

Your diagram is very close to my installation. The air con is suspended to the roof joists by eight straps. I assume this was done to align the unit to the plenum and allow space for the drain pan. The Carrier model number is what is on the name plate. It is what it is. Ha....

Will try to post picture as soon as possible.

Cheers
 
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Old 01-01-12, 10:17 AM
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doing a search for the model number given it looks like you posted the question to a number of sites. We need pictures. Post your pics to a site such as photobucket and then post the URL to the picture here on this thread.
 
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Old 01-03-12, 11:31 AM
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Old 01-03-12, 11:50 AM
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Can't believe it

After a lot of messing around the pictures finally went thru. Now if I could only remember what I did. Please note that cover on furnace happened to be off at time of photos. It is normally on furnace. The duct work to right of A/C unit is T ed into the plenum which runs the full length of house. Insulation on top of furnace is just some extra that I placed on top of duct work to store. As A/C unit is suspended, it would seem logical to support unit before taking off front panel. Any ideas??

Cheers,
 
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Old 01-03-12, 07:30 PM
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yes, the door should be on the furnace. Remove the front door of the evap coil (all taped up) to check the orientation of the coil and check to see if the apex of the coil could be removed to access the inlet side of the coil to clean. Or you may have a slab coil that is angled and easy to access the inlet side. Remove the door to find out and possibly post pictures.
 
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Old 01-05-12, 05:08 PM
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Wow, that is an old looking evaporator coil. I'd guess early 80's.
It probably is dirty.

I'd recommend a new, and larger, secondary pan under that evaporator coil before cleaning.
 
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Old 01-07-12, 03:51 PM
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Old 01-07-12, 03:57 PM
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Photo problems

Hope you get these photos. More work sending photos then taking apart A/C. Cleaned with coil cleaner and lots of water. Cant believe no freon leak with all that corrosion. Don't know how to get at other side of coil without taking apart duct work.
Cheers
 
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Old 01-16-12, 10:26 AM
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If you select the IMG Code you can paste the pics on your post...







 
 

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