I have a central air system and also an air purification all as part of the same system.

The air is continuously being recirculated through the air filter system whether the air conditioner is running or not.

When the air conditioner is running, everything smells fine, but when the air conditioner is not running and just the air is being recirculated, I smell a musty odor when I walk into my closed house.

I have had the system cleaned, and the filter has also been recently changed. Does anyone have any idea why this would be occurring? Also - from what I understand, this could be unhealthy - - comments? What do I do???

As in most systems, your evaporator coil (this is the cooling part) is after these filters. The oder is moisture on your coil and condensate pan from condensate. You stated that you have had your ducts cleaned. Did they also clean the evap. coil. If not, you may have it cleaned, this may help. I would not trust this job to duct cleaner companies unless they have the training needed to work with these systems. I would have a trained, HVAC service person do it.

As this coil warms up durring off cycles, a type of mildew starts to grow and gives off this "musty' smell. When it is on, the cold coil slows down this growth and the condensate kind of "flushes" this away.

This oder will dispate as the coil dries out.

There are tablets that can be put in the condensate drain pan, but I have found that in most home installations, it is almost impossible for the home owner as no prevision were made to do this.

These tablets slowly relaese a "biocide" that will cut down on these growths.

Hope this has been of some help.

WOW

do you think this is something that they should have done when I had it serviced at the end of April? I have a service contract with the company that did the installation of my central air - so they are definitely knowledgeable in all areas of HVAC (or so they should be).

Anyway - - I had it serviced - cleaned, filters changed, etc. as part of my maintenance contract at the end of April - - they had to come back again at the beginning of this month cause water was everywhere and they said cause the drain needed to be cleaned (which they did for free this time cause it had just been done - supposedly I guess).

So - - do you think that this is something they would have done? When he was here I told him about the musty smell and he put some lemon chemical stuff in - - and the house smelled like lemon and chems, but next day it was back to musty.....

Remember that mildew? Well, along with that are several biologicals that grow in that water. Along with dirt, they block up condensate drains.

Cleaning that coil may or may not be inclued with their contract service. The fact that they had to come back because of a drain plugged tells me they did not do a good job with your "Spring Clean and Check" as we call it. You should not have plugged it up that quickly. It is not an easy job on most residential air cond. and is an extra. Read your contract to see if they have it listed there. If they don't say "Not Included" then they should be cleaning it.

We, my ex-company used a spray that you sprayed on, soak and let the condensate rinse away. But you need to get to both sides of the coil.

Now I must put in the usual clause here. I don't know how old your system is. I am not there to see your system or do I know the qualifications of your service person. I will tell you this, from what you are telling me, you should have the coil cleaned. This should be done about every five years in most cases. The fact that you have your system ALWAYS MOVING AIR, leads me to believe that you should have your cleaned a little more ofter.

Ask me if I clean mine every five years, NO. Being in the business, I do inspect mine once a year. When needed, I will do it my way.

If you would like a list of things that should be in you maintenance contract, just ask as a separate question.

Just a note for all who will read this. Most times, these clean and check are just a way to get at you furnace-air cond. to find out if they can sell you something. Not that they are not performing a good service but it is a "Lost leader" item in order to generate sales. In most cases, they will not sell you something you don't need.

[This message was edited by Walks On Water on 07-22-02 at 12:29 PM.]

is only 3 years old...

I have the same issue, but cannot identify where e the condensate or drip pan are - Are these enclosed? how do I access them? Do i need a professional to do it?

quote:

Originally posted by seeker:
I have the same issue, but cannot identify where e the condensate or drip pan are - Are these enclosed? how do I access them? Do i need a professional to do it?

I'd have the Same Question if this happened to Me though to save you a Hours Labour costs for a few minutes "Look see"
This image search and a Friend who is Mechanically Minded will ID this item which will either Drain outside or be plumbed into the internal Household drainage

Be aware that there are Many different Design layouts From Straight through to Drain/evaporation pan inside or Underneath the Inlet Housing
The Most common May Be a Looped Tube to the Motor on the Unit and the Heat on the Drip tray
dries any moisture This Is how its relative the Fridge deals with Moisture
Some commercial fridges could not deal with the Defrosting so they provided a Tank to catch the Water (several Pints Daily) Dehumifiers use this Method

Fix : Just ensure the Item is not clogged and is draining at the exit point (Be good for another Year or so)

See this site. It will help you visualize the parts.

My Air

If you have a vertical unit, that is one that either blows up on down, it will have an “A” coil or one that looks like half of the “A” coil. That is called a slanted coil.

If you have a horizontal unit, then you will have a flat, straight up and down coil.

In any case, all coils have a drain pan or condensate pan on the bottom to catch and channel to condensate water out and away.

This water, as I have stated before, can collect small amounts of dirt as well as grow biologics. These can plug up your drain line. The bad thing is that the home owner can not easily get in to the plenum to get at the coil to clean it or the drain pan.

You will have to call for service. My company would clean it as part of the “Spring Tune Up” or at least check the coil and clean the pan. Cleaning the coil takes some time and cost more.

One note here, if you can see you hand through your "New" filter, it won't filter that well. If you can see through it, dirt will get through it. I like the pleated ones that you can't see through. You may have to change them more often, but it will save you money in the long run.

"When should I change filters?" At least spring and fall. More often if you open your house up to the out side. I have seen some filters the "Whistle" when they need changing. They don't work that well depending on your unit.