How to access evaporator coils in sealed case - pictures inside


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Old 03-08-11, 07:19 AM
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How to access evaporator coils in sealed case - pictures inside

Hey again...I have Aspen-made evaporators BVR24 (info here: http://www.aspenmfg.com/documents/pr...G2480-0608.pdf ) on top of Lennox Value Series furnaces in the basement and attic, see the photos below. I'd like to clean the coils after 10 years of operation but there is no access doors or removable panels in either unit. The box seems to be made from some sort of non-metal material, perhaps fiberglass.

How would you access the coils for cleaning? Thanks for the help, in advance!

basement system:
Imageshack - 1000603s.jpg
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attic:
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Last edited by pics20; 03-08-11 at 07:54 AM.
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Old 03-08-11, 10:49 AM
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Looks to me like whoever did the install used ductboard, which is okay for ducts but definitely not for the coil. I think you will need to destroy the ductboard casing and then either redo it with new ductboard or do it correctly with sheet metal.

Just my opinion.
 
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Old 03-08-11, 01:07 PM
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some installers do it that way, I don't like it because there is no access to the coil, you will have to make one, or have one made for you.
 
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Old 03-09-11, 09:32 AM
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Thanks gents. What a crappy job...it was Pulte Homes and Reliance Heating who built the house and installed the system.

Should I simply cut along the edges of the front board to make an opening or could I clean the bottom side of the coils from underneath thru the furnace?

If I cut the board is aluminum foil tape strong enough to keep the piece in place or should I really try to construct some kind of a sheet metal door for the evaporator? Where should I look for ideas?
 
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Old 03-12-11, 12:10 PM
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Remove the silver tape around the panel, remove the 5/16 inch screws along the service panel, remove the inner triangular panel to get to the dirty side of your cased evaporator coil.

Example of inner panel...


Then you get to the tough part.
 

Last edited by Houston204; 03-12-11 at 12:40 PM.
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Old 03-13-11, 09:52 AM
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The capped secondary drain on that evaporator coil should be piped down to the pan under your furnace to protect your furnace when the primary drain backs up.
 
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Old 03-15-11, 08:02 AM
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Thank you Houston for getting back on this!!! Just wondering...the "box" around the evaporator is made of fiberglass, I don't know if there are the panel screws you mention. If that is the case I guess I just need to cut an opening in the board along the lines that you marked in the picture. Also I cannot see aluminum tape at the edges, it is something that looks like a silver colored paste or caulk. I added the tape where the pipes get into the box. This basement unit is on concrete floor with no pan, I'll figure out something for the capped outlet.

BTW Home Depot sells "AC Flow" Evaporator Cleaner in a plastic spray bottle and shows a condenser unit in the bottle...is it for the outdoor unit father than for the indoor evaporator?
 
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Old 03-16-11, 05:00 PM
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I see a metal cased evaporator coil. I circled the screw locations on top of the metal panel. You will also have 3 or 4 screws along the right side of the panel. You may also have 2 or 3 screws along the bottom of the panel.

You have gray duct mastic over silver duct tape. I'd start at the top right of the panel with my duct board knife to remove enough mastic to verify that 2 panels meet here. Some triangular inner panels are more servicable than the one I displayed.

Does your coil cleaner display No Rinse Required? If you need to rinse, it is for outdoor units. (or pumpdown removing and cleaning outside by a pro)

Return air leaks can get a coil very dirty.
If a vertical evaporator coil is very dirty, green coil cleaner may not be enough.
Remember that your furnace motors, and circuit boards should not get wet
or damage can occur.
 
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Old 03-16-11, 08:46 PM
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ImageShack® - Online Photo and Video Hosting
I see a 5/16" hex screw on the right side of the panel by the insulated suction line
 
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Old 03-19-11, 06:35 AM
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Hi Houston, OK, I'll proceed as you suggested by using a knife to remove the mastic. The PDF spec sheet file I linked shows the evaporator in metal casing. I am thus assuming the whole thing is inside the box made from duct board.

I'll report back my findings.

I actually didn't buy the "AC Flow" but I remember reading in the bottle it would require rinsing (ur running the AC, not sure) and that the liquid was alkaline. Home Depot employee said it it is for the outdoor unit but the product is called "AC Flow Evaporator Cleaner". Very little info on the net about that product, found a review on it though: Clean your Evaporator Coils with AC Flow

Re the 5/16" hex screw...I cannot see it in the photo but I'll check the actual unit when I begin to work on it. Thanks again, I'll be back soon!!
 
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Old 03-19-11, 08:30 AM
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It is not ductboard, it is metal. Ductboard is a dense fiberglass with foil backing.



The fact that that your installers used foil tape before applying mastic will help in removing your panel. Clear away the tape and mastic aroung the bumps created by screws, remove the screws and cut around the rest of the panel and it should come off. I do not recommend using a Leatherman to remove the mastic.

The inner panel is the more critical job. Small feeder tubes can leak refrigerant if you move them out of your way.
 
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Old 03-19-11, 09:28 AM
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I checked and the panels actually may be metal...they feel and respond to tapping like they could be fiberglass with orange skin patterns though. I can see where the screws are...I'll try removing the panel later today or tomorrow. How should I handle the pipes + exhaust...they are all blocking the front panel area. I am guessing due to the pipes thru the panel I can pull the panel out just a few inches unless I cut the openings larger. How a pro would overcome those obstacles?
 
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Old 03-19-11, 09:53 AM
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I'd shut off the gas to the furnace, disconnect the vent pipe from the furnace and move it over a bit.

Been in the biz for 20 years. It is metal.
 
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Old 03-19-11, 09:59 AM
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Thanks for super quick reply, I can notice you know the stuff! I'll do that. What about the coolant pipes thru the panel, do you think I have move the panel out enough without making the holes larger?
 
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Old 03-19-11, 10:07 AM
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The refrigerant line pass through a separate panel. You might be able to clean your coil without entirely removing the right panel.
 
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Old 03-19-11, 10:52 AM
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I see, that would be great! I'll let you know what happens. Thanks again for your help!
 
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Old 02-28-12, 11:25 AM
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OK, so I read through the postings and it doesn't say how to actually get into a sealed coil box. Is there a tool like a "dremel" that i can set at a certain depth to cut an access panel? should i cut 2, one on each side? The A/C has a musty smell and cleaning the coils sounds about right. But with no access panel this is getting pretty frustrating.
 
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Old 02-28-12, 12:27 PM
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@homerigger

Start your own thread with pictures.
 
 

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