Clogged Coil?

[vlad59]

Our A/C unit delivers hardly any flow. It is a rooftop Lennox Unit that is 11 years old. The building is a body shop and it appears that the dried paint overspray and sanding dust has clogged coil fins.

Several years ago we've had the same problems and our HVAC guys had cleaned the coil with some chemicals which solved the problem. Unfortunately, they are out of business and our present HVAC people have no clue about coil cleaning.

We've tried cleaning with detergent and hot water to no avail.
Does anyone here knows what is the right process?

All replies appreciated.

Vlad

[klrogers]

The right process is.......






Call a HVAC company that knows what they are doing

[otto]

Dried paint & overspray......hmmmmmmmmmmm.....use some pretty harsh solvents or replace the coil.

[teckster]

call a service company and tell them the problem and that it is paint in the coil and if they can help you or not. dont be shy be honest and tell them if they cant fix it you wont pay. and that you have hade this problem before and you know there is a fix.

[amickracing]

Not only is it a good idea to clean the coil, but like teck mentioned too... there has to be something done to fix this. Either a better filter system, more frequent maintenance or something along those lines.

[y7turbo]

do like everyone else says and call a commercial hvac company to clean the coils. they have the right cleaners and sometimes will use pressure washers on very dirty evaps.

after the problem is fixed, try and use pleated filters and change them often. your town should have filter service companies that you can hire to change your filters if your going to forget to do it yourself.

[madhat]

Try Renewz(sp) it will eat most paints off of coils. Do not mix it any stronger than label or it could damage the coil. PS It's a really good bottom paint remover for boats at the end of the season. You need to use the yellow paint arrester filters or you could end up talking to the EPA!

[socal]

Replace the coil. Epoxy reducer{thinner) will take all paint off the coils and the varnish off yo theeth. I'd go with the new coil.

[gordon grant]

there are commercial coil cleaning agents that will clean this up, for you , you need a pressure spray tank with hand pump , spray coils let sit about 1 hour , then pressure wash , you may have to do several times before the coil is clean enough to operste properly , be very careful with these cleaners they can burn you severely through your clothing , wear a face shield to protect your eyes and face , rubber pants or rain gear is also good , this should be done by an experienced H.V.A.C. Technician who has had experience doing this befor , not recommended for the average joe or apprentice , after are finished washing with the pressure washer allow about half an hour for coild to drain off residule water and chemicals , let it dry , or you may cause water and chemical damage in side the building , cieling tiles , diffusers , etc. these cleaners are available at you Refrigeration Suppliers.
NOTE: this type of work can not be rushed to save the customer money , it has to be done properly or you will be back at your own expence and your company's , so do it once , do it right , every one is happy ..... Don H.V.A.C.R. Tech.

[ct2]

lets think about this for a minute

this is a body and fender shop and the coil is plugged with paint by products

how much has built up in the duct work? paint vapors will go right through a filter

[absrbrtek]

This should probably be a 100% MUA unit with proper exhuast systems installed. Replace the system and have it designed properly.

[ej45]

Originally posted by teckster
call a service company and tell them the problem and that it is paint in the coil and if they can help you or not. dont be shy be honest and tell them if they cant fix it you wont pay. and that you have hade this problem before and you know there is a fix. I like this idea, (tell them they cant fix it you wont pay) BULLSH**! This is not Vegas Bud. The proposed service company did not install mis-applied equipment with out the proper filter equipment, why should they risk the cost of chemical and labor for for a problem they did not cause. How do they know this is the same problem? Maybe someone removed prefilters and now the repair is a new coil. Dried paint between the coils is not going the be a quick fix.

MUAHU

[pecmsg]

You have more to worry about then a bad coil. You need to eliminate the fumes from getting in there. There should be a large filtered exhaust fan in that shop, all your thinners and paints will damage the HVAC equipment. (Not to mention what the thinners will do to an open winding motor, copper and aluminum.)
MA has some pretty stiff regulations concerning paint rooms. Please call a contractor that specializes in such work.

[atmosphere]

ej has it right- A dedicated 100% Makeup air unit is required.

There are too many variables here that are not in the control of the installer/ service contractor.

ANY work on this unit should be done with no warranty stated or implied.

Sounds like a new evap. coil is in order when the labor and material is considered as well as the safety issues with the hot solvents being recommended.

We call ourselves HVAC men but it appears that more and more less and less attention is being given to the Ventilation side of this industry.
At the same time more and more legislation is being passed concerning this very subject- Demand Ventilation for starters.

Personally, I think you should design a proper ventilation system for this shop. It is a natural sale right now as the consequences and the costs of NOT having one is evident and observable to the shop owner.

Most business owners would appreciate someone who could explain the big picture here in laymans terms.

Looks like there is some new work here during the in between season.

Just a suggestion.

And Good Luck - Vegas or not.

[jpb2]

Originally posted by absrbrtek
This should probably be a 100% MUA unit with proper exhuast systems installed. Replace the system and have it designed properly.



I agree

[vlad59]

Thank you all for your suggestions. We already have filtered exhaust fan (explosionproof). We do plan to have a setup with MUA unit installed next summer.

[Edited by vlad59 on 09-11-2006 at 10:19 AM]