# No access to HVAC Evaporator Coil



## jay235 (Dec 7, 2009)

Here are some pics


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## yuri (Nov 29, 2008)

go to HDepot and buy a pair of sheet metal snips. one cuts left the other right. under $30. and a piece of sheet metal/ joist liner tin which you can buy there and some sheet metal screws and silver foil duct tape. yellow snips cut straight.


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## jay235 (Dec 7, 2009)

Which side would be best place to cut? Front where the copper lines are going in or on the back (other side of copper pipes?


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## yuri (Nov 29, 2008)

whatever is easier. the coil is a ^ shape with the Freon going in the front and the ^ in that direction too. get 2 pieces of 12x12 tin as you may want to cut both sides. not easy or fun to get under that coil especially if it has cat/dog hair in it. if it is real dirty you should spray it with Simple Green cleaner and then flush it with clean water. Have fun.:yes:


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## gregzoll (Dec 25, 2006)

Look on the oter sides. There should be a seam where they pushed the one panel on. Otherwise they would not have been able to place the A-coil on top, without doing a lot of magic tricks, to do so if it was placed inside that plenum to begin with.

Now of course there are some where the coil is inside a box, but even those have an access point on them.


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## SeniorSitizen (Sep 10, 2012)

Some seemingly DIY jobs are best left for the professions and in my opinion this is one of those.


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## Technow (Nov 12, 2010)

Fairview said:


> Some seemingly DIY jobs are best left for the professions and in my opinion this is one of those.


 
Naw...he should go for it!


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## PoleCat (Sep 2, 2009)

I just did mine today and I haven't got a lick of sense. We have been here 20 years and have a whole mess of cats so I figured it was time. And it was too.


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## jay235 (Dec 7, 2009)

Yeah, I don't mind cutting the sucker up and making a small access door. The next cleaning will be a lot easier.


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## gregzoll (Dec 25, 2006)

Fairview said:


> Some seemingly DIY jobs are best left for the professions and in my opinion this is one of those.


Why, I did mine when I had to open it up to put the A-Coil in my plenum. Of course it meant taking apart the whole upflow to remove the panel from the seam, but was able to do it, then put it all back together after done.

Yes there are some things that a homeowner may want to farm out, that either is beyond their abilities, or too costly to go out and rent or buy all of the tools needed, or have a time constraint that will cause them to call someone that can do it in 1/4 or 1/2 the time.

For example, I could have replaced the next door neighbor's Cast Iron Closet Flange, but that would have meant ordering the Fernco doughnut needed to replace the cast with PVC, since I cannot get it locally at any of the big box stores here in town, but could get it through a friend's mom who runs a supply house.

Then add in the time it would have taken me compared to just farming it out to a professional, who had the job done in two hours today for her, including putting the toilet in place and a new shut-off for her, while I was at the dr's office.


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## yuri (Nov 29, 2008)

cleaning a coil is not Rocket Science. we are not talking about playing with gas lines or anything dangerous. buy a pair of those Mechanix cutproof work gloves (HDepot should have some) as sheet metal cuts like a knife.


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## Methodical (May 21, 2013)

jay235 said:


> Here are some pics
> 
> View attachment 73622
> 
> ...


You may also want to consider a safety shut off switch in the secondary condensation drain.


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## jay235 (Dec 7, 2009)

You are correct. Right now it just has a red cap over the second opening.


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## ryandeen (Jan 18, 2013)

yuri said:


> cleaning a coil is not Rocket Science. we are not talking about playing with gas lines or anything dangerous. buy a pair of those Mechanix cutproof work gloves (HDepot should have some) as sheet metal cuts like a knife.


Lol

Sent from my iPhone using DIY Forum


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## Methodical (May 21, 2013)

Jay, how did it turn out?

I just cleaned the coil in my rental unit. Man, that was some nasty junk on the coil - about 1/8" thick and nasty. I got it off though. I also had to install a safety switch in the secondary drain, because the installer left it wide open and the tenants heard water leaking (secondary drain) from the closet where the unit is installed, plus they used 1/2" drain pipe. I took care and now the unit is good to go.

Hope all worked out for you.


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## jay235 (Dec 7, 2009)

I haven't gotten around to doing it. Here in Jersey, it's been very hot lately and I didn't want to fiddle with it at the moment. Did you have access to the coil or did you have to cut it open?


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## Methodical (May 21, 2013)

jay235 said:


> I haven't gotten around to doing it. Here in Jersey, it's been very hot lately and I didn't want to fiddle with it at the moment. Did you have access to the coil or did you have to cut it open?


Fortunately, I had access at the front - no cutting. I can understand not screwing with things until it cools down a bit. We had that heat down here in MD, too. It's a bit cooler today. Do you plan to install the safety switch - it's an easy install (see below). Cheap insurance.

http://ows.rectorseal.com/Safe-T-Switch-SS2.php

http://ows.rectorseal.com/product-data/safe-t-switch-ss2/inst-SS2.PDF


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## jay235 (Dec 7, 2009)

I cut out the duct today and opened up the inside of the a-coil. Not much dirt/gunk at all which was pretty surprising given the system is over 15 years old. I guess the regular change to the air filter helps. I still sprayed on the coil cleaner and then sprayed on water since I had opened it up.


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## beenthere (Oct 11, 2008)

Did you cut a hole so that you are looking at the inlet or outlet side of the coil. Outlet side usually does look clean, when the inlet side is dirty.


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## jay235 (Dec 7, 2009)

beenthere said:


> Did you cut a hole so that you are looking at the inlet or outlet side of the coil. Outlet side usually does look clean, when the inlet side is dirty.


Yes - I opened the panel so that I can also see the inside of the coils. Both sides looked pretty clean.


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## beenthere (Oct 11, 2008)

Usually, when I go to all the trouble to cut open a plenum to inspect a coil. I spray it with cleaner even if it looks clean. just to make sure.


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## jay235 (Dec 7, 2009)

Yes, completely agree with you. I did spray with the coil cleaner.


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## SouthLake (Jul 18, 2012)

I have a similar situation as OP. 
this system was installed about 2 years ago before I bought the house. 

One side has excellent access. front and rear def not. side facing return has okay access, not ideal. I have never had a unit where there is no panel to pop open to view the coil. this is pretty dumb design... 

I would like to be able to clean this thing, and install a UV light while im there. 

The sheet metal wrap around the coil appears to be attached as a "U", with the opening facing the side with all the pipes. The back of the U has about 2 inches of clearance behind it against the wall argh.

so do i just take tin snips, slice open one side of this thing (nearest the wall). that will give me access to clean the coil? then put the metal back and seal it with tape?

im afraid to go cutting this box without knowing whats on the inside of the sheet metal or the orientation of the coil... 

maybe i should use my HVAC guy and have him do the opening for me and go from there.


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## yuri (Nov 29, 2008)

I would recommend you get the HVAC guy AND he should do a proper maintenance checkup. Most important part is to check the freon level which a DIYer cannot do without gauges etc.

The furnace also needs maintenance as there is a flame sensor which needs cleaning. Not that easy to get at or out on that furnace.


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## SouthLake (Jul 18, 2012)

Thanks,
I have the gauge set from installing and charging my garage Mitsu Mini-Split, but this system is new to me. the mini split is easy... 

if he's going to be here to cut access i might as well get him to do everything, but once i have access id like to be able to clean this on my own going forward. im just reluctant to go slicing open the metal with the coil behind it... and that seems to be whats recommended is this thread.


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## yuri (Nov 29, 2008)

You can do it and I can describe it but what's the point if he can do it?

It looks like you have a expensive Signature series furnace and some nice toys so I would get it checked properly and maintained.:smile:


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## user_12345a (Nov 23, 2014)

You should not have to clean a coil after 2 years or ever.

The filter is supposed to keep the system clean.

also the secondary heat exchanger will capture most of the dust, very little will go to the coil.

it's not normal maintenance, it's a repair cause by another problem.

All you need to do is keep the filter and outdoor coil clean, open the blower compartment and check the wheel for dirt buildup.

you can clock the gas meter to check the fuel input and check the temperature split in heating and cooling mode.

once's a system is properly set up you don't need someone year after year on such new equipment.


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## yuri (Nov 29, 2008)

Not true. :vs_no_no_no:

The fin spacing on the secondary coil is very wide compared to the AC coil so the cooling coil catches dirt fast. Dirt can get on the cooling coil if the filter is not properly maintained but to say a secondary coil works like a filter is nonsense. FYI Carrier uses a plate secondary coil and it catches no dirt.:wink2:

People invest $6000-$10000 or more in high end HVAC units and like to have maintenance done to catch the unit leaking freon ( if it does ) and have their drains checked etc. 

Has nothing to do with the age of the unit.


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## user_12345a (Nov 23, 2014)

carrier dropped that design and went to finned stainless due to class action suite and lots of warranty claims, no? 

*main point being*, if the filter is doing it's job, the coil should never have to be pulled in it's life. if the filter is letting dust through the blower wheel and secondary will be dirty as well to an extent, if they're clean the coil should be clean as well. if not maybe coil has dirt too.

likewise if the gas pressure, charge and airflow/fan speed were properly set at factory or in the field, no reason to get those checked year after year. 

the owner can clock the gas meter and check temperature rise for heat and if it changes year after year know something is wrong.

likewise, for cooling the owner can check the split once a year with a inexpensive thermometer and even check wetbulb to take humidity into consideration.

If it's leaking "freon" the split will change and owner will know to make call.

it's a lot of money to have someone out every year.

if everything is working right and looks clean, kind of overkill to call someone every year to do a cleaning and checkup on something so new.


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## yuri (Nov 29, 2008)

Our OP just wanted to know how to cut a hole in his plenum to check his coil.

I give advice to people so they don't listen to urban myths and HVAC wannabee techs telling them to not do maintenance.

They then call me and freak out when their drain plugs and floods their furnace with water and blows the brains out of their fancy ECM motor AND $1000 circuit board.

Periodic maintenance is necessary. May not have to do it every year but every second year is a good idea. As long as you are not using some "fly by night" outfit then it is worth the money.

If a homeowner wants to learn about HVAC maintenance that is fine but for the rest of the folks proper maintenance is a good idea.


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## beenthere (Oct 11, 2008)

user_12345a said:


> You should not have to clean a coil after 2 years or ever.
> 
> If a good air filter was always used, it shouldn't have to be cleaned after 2 years. No one knows what air filter was used by the original owner.
> 
> ...


I have customers that never have their systems checked. I get to clean their evap coils every 3 to 5 years. They use MERV 8 filters.

Takes a well sealed MERV 11 or higher to keep the secondary and evap coil from ever needing cleaned(or for at least 10 years).


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## user_12345a (Nov 23, 2014)

> I give advice to people so they don't listen to urban myths and HVAC wannabee techs telling them to not do maintenance.


no, not really wannabee, more of trying to be helpful. easy to resort to bashing if you disagree.

yes, do the basic maintenance. (which definitely includes checking the drain)

waste money on things that can be done by the owner easily or aren't needed? no.

annual or even bi-annual professional maintenance on new stuff is a cash cow for the industry and that's why it's pushed. People are also creatures of habit and don't question things especially when they bring in income.

i suspect professional maintenance can make things worse if not needed, cost aside; every time you unscrew and screw a panel back on you risk damaging the hole so the screw can't be re-tightened. Putting gauges on an a/c can cause a little refrigerant loss. Checking gas pressure on gas or propane appliances can be dangerous.

This is all assuming a baseline has been established.

It's the same for us - *you don't go an get a full body CT scan routinely if there are no symptoms, just in case* - there is a risk of harm and it costs lots of $$$-> cumulative damage from radiation exposure and false positives.



> I have customers that never have their systems checked. I get to clean their evap coils every 3 to 5 years. They use MERV 8 filters.


You're assuming it's being changed and isn't leaking around the edges when saying merv 8 filtration won't keep a coil very clean and the coil itself is like a merv 8.



use the right filter for the application (which i suspect merv7 or 8 would be enough for a coil) and if it's doing it's job, shouldn't have to clean anything.

what's the point of filter if it doesn't keep things perfectly clean? that's the whole point.

if things are done properly, no leakage, good fit, changed as needed, you shouldn't have to clean coils.


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## beenthere (Oct 11, 2008)

user_12345a said:


> You're assuming it's being changed and isn't leaking around the edges.
> 
> No, your assuming that it isn't leaking around the edges, and is changed regularly. I never assume that, since I know from experience that many do leak, and many are not changed as often as they should be. And that coils do need to be cleaned.
> 
> ...


The average air filter isn't suppose to keep everything perfectly clean. Thats just a myth you believe. 

Needs to be a MERV 11 or better to keep a furnace or A/C nearly as clean as you say a filter should keep a system. And there can be no leakage around the air filter, or its housing/cabinet.


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## fischdf (Aug 22, 2017)

This thread has been very helpful to me as I have a similar problem, but I'm going to open another one instead of hijacking this one. I'm new here, so I hope that's the right thing to do.
Denise


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## supers05 (May 23, 2015)

@fischdf
That is best. 

Cheers!


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