Evaporator coil cleaning - how often and how much

Should be checked at least once per year.
They can get pretty dirty depending on the setup of the equipment.
They can be difficult to clean properly.
Once they get really bad you have to pump the system down, remove the coil, and take it outdoors to use a hose and chemical cleaner.

If the filter is doing its job* and air isn't leaking around it, the evap should never need to be cleaned. It's not part of normal maintenance.

*Needs to at least merv 6, some say at least merv 8. Proper filter sizing is important to be able to use something decent without reducing airflow too much.

$250 sounds cheap for evap cleaning if it has to be removed to access the inlet side.

I agree with post #3. Keep good filters in it and it will last the life of the system. I clean my own condenser regularly but without coil cleaner. You have to be careful with coil cleaner or it will eat up the fins.

Thanks everyone.

You've been a great help.

This is also what I have seen in my admittedly narrow experience. The coil in my system developed a leak when it was about 15 years old. I had been using the pleated filters in the mid range, like MERV 6 to 8 or equivalent for that entire time. When I replaced the coil I saw that the original one was really pretty clean. I'm sure this varies a lot based on how a system is installed, set up and maintained. But IMO with a little due diligence they should not really need cleaning.

user_12345a said:

If the filter is doing its job* and air isn't leaking around it, the evap should never need to be cleaned. It's not part of normal maintenance.

*Needs to at least merv 6, some say at least merv 8. Proper filter sizing is important to be able to use something decent without reducing airflow too much.

$250 sounds cheap for evap cleaning if it has to be removed to access the inlet side.

Click to expand...

Once upon a time I believe it was BeenThere who recommended cleaning the condenser coils with Simple Green or similar. I have been doing that every couple of years with great results. My outside condenser is a builder's grade Bryant 3 1/2 ton that is ~24 years old and still going strong.

Old Thomas said:

I agree with post #3. Keep good filters in it and it will last the life of the system. I clean my own condenser regularly but without coil cleaner. You have to be careful with coil cleaner or it will eat up the fins.

Click to expand...

@SeniorSitizen That's a normal variation of ∆ T since humidity is a factor. You have a healthy system if you get 20° under normal humidity.

Sometimes a 15F drop at normal humidity can be okay - it depends on the fan speed.

A 20f drop can not be okay if airflow is low and it's covering up a refrigeration problem.

More information is required to see if a system is working properly.

ken33xx said:

I got my AC unit checked today. This included hosing down the condenser coils. I have this done once a year.

I have the evaporator coils checked as well and I was told they wouldn't need to be cleaned.

This is a new AC tech and he comes recommended from a number of people in the area. His service call is on the low-end ($50.)

He mentioned cleaning the evaporator coils should they need cleaning will run around $250 which sounds outrageous.

I asked why so pricey and he said it is difficult to clean the evaporator coils.

However, I'm thinking you simply check the coils and if necessary spray a cleaner on them.

Am I missing something?

Or is such a cleaning charge a ripoff?

Thanks

Click to expand...

Depends on what type of cleaning is done.

Sometimes just spraying an evap coil cleaner on the air discharge side doesn't clean the air inlet side.

So sometimes you end up cutting open the return duct to spray the coil, and possibly even have to comb the dirt off/out.

I can assure you that having to pull the evap coil and cleaning it isn't outrageously priced at $250. It's what I'd call hard earned money.

If done properly, it will take 3~4 hours maybe longer. It requires extracting the charge and disconnecting the refer lines, drain line and whatever else may be in the way.. maybe the flue pipe and humidifier bypass duct. Then taking the coil outside and cleaning it. Then installing it and connecting all the lines and ducting back. Maybe installing a filter drier. Then evacuating the system (an hour minimum. longer is better, using micron gauge). Then recharging the system and checking the operation. You'll be getting your money's worth.

That said, don't do it unless the tech says you need it. Most won't push for that kind of work.