assuming dirty AC coil...what to do?

[Guest guest]

I have an HVAC guy coming tomorrow afternoon to look over our AC coil and filter

and give us an estimate and I'm hoping to be prepared.

Although this guy is recommending UV lights and a fancy Aprilaire filter (not

sure if it's electrostatic or what), he at least seems open minded and

interested in trying to solve the problem of what's coming out of the vents

that's giving me hives. Some of the people I called were pretty dismissive and

I didn't feel like I could work with them at all.

After everything I've read here and on Jeff's site, here are my questions--any

feedback much appreciated!

--We definitely need the AC coil cleaned or replaced. Does using a chemical to

clean mold off a coil even work? Seems like it might be only partially

effective at best, and spread more mold through the system at worst. I'm

leaning toward replacing the coil and starting clean, despite the cost. The

coil is old.

--The duct cleaner said the motor in our furnace is really dirty and needs to be

pulled out and cleaned. The clothes dryer duct was loose, and it's near the

furnace, so I'm guessing lots of dust came from there. Aside from replacing the

coil and cleaning the furnace motor, is there anything else I should have

cleaned or replaced in the hopes of having a clean, or at least much cleaner

system?

--There's wiggle room around our furnace filter when it fits in its slot. The

filter is the right size. How can I make sure, if we get a properly sized

disposable MERV 8 or 11 filter, that air and particulates can't just scoot

around the edges and into the system? One advantage of the Aprilaire is that

it's airtight.

--Our furnace is pretty old, possibly original to the house built in 1947. As

long as I replace a MERV 8 or 11 filter religiously, would it strain the system

to have such a strong filter?

Many thanks for any thoughts. After looking through the archives I can't

believe how many people have had similar problems and how insistent the industry

seems to be on sticking with ineffective practices.

Also, if anyone knows of a good HVAC person in northeast Ohio, let me know.

Amy

[Guest guest]

Amy,

The AprilAire filter is a good one. I like it because it combines a

mechanical filter with an electrostatic field. Which is placed in

front of the media. It functions at or near HEPA effectiveness

without creating a huge pressure drop which restricts airflow.

But following Jeff May's advise about the disposable filters will be

produce equivalent results at less short-term cost. How many

throw-aways can you buy for the cost of an AprilAire?

I don't like UV in residential systems because the light isn't bright

enough over a long enough distance to kill mold. Besides, killing

mold doesn't help. UV can be effective at keeping the A/C coils

and drip pan clean from growth of mold and especially bacteria.

But it needs multiple lights to shine on both sides of the fins plus

above and below so there are no shadows. Residential UV

systems don't even come close to this performance.

To find someone in your area there are two possibilities:

1. Go to the National Air Duct Cleaners Assoc at www.nadca.com

and search for a NADCA members. They aren't all good but you

have a better chance of finding a good one there. BTW, a

NADCA member familiar with their ADC 2006 standard will know

about evaluating A/C coils and how to clean them.

2. Another similar organization is the Air Conditioning Contractors

of America (ACCA) at www.acca.org. They have a Find a

Contractor link also and their own ANSI accredited standard

Same information as for NADCA.

Other information in CAPS:

> --We definitely need the AC coil cleaned or replaced. Does using a chemical to

clean mold off a coil even

> work? Seems like it might be only partially effective at best, and spread more

mold through the system at

> worst. I'm leaning toward replacing the coil and starting clean, despite the

cost. The coil is old.

BECAUSE OF THE AGE IT MIGHT BE BETTER TO

REPLACE. HOWEVER, MOST COILS ARE REMOVED

AND THEN CLEANED. IT IS VERY DIFFICULT TO

CLEAN IN-PLACE WITHOUT DAMAGING THE

FRAGILE FINS. EITHER WAY, THE TECHNICIAN

MUST BE EPA CERTIFIED TO HANDLE THE

COOLANT RELEASED DURING REMOVAL AND

RECHARGING.

>

> --The duct cleaner said the motor in our furnace is really dirty and needs to

be pulled out and cleaned. The

> clothes dryer duct was loose, and it's near the furnace, so I'm guessing lots

of dust came from there. Aside

> from replacing the coil and cleaning the furnace motor, is there anything else

I should have cleaned or

> replaced in the hopes of having a clean, or at least much cleaner system?

ACTUALLY, THE DUST ACCUMULATES ON THE

MOTOR AND THE FAN BLADES AND IS THEN

DISTRIBUTED WITH THE AIR. THEY SHOULD BE

REMOVED FROM THE CABINET AND CLEANED

OUTSIDE. ALL AIR-SIDE SURFACES SHOULD BE

CLEANED. YOU CAN DOWNLOAD THE NADCA

STANDARD FROM THEIR WEB SITE AND SEE

EXACTLY WHAT THEY RECOMMEND.

>

> --There's wiggle room around our furnace filter when it fits in its slot. The

filter is the right size. How can I

> make sure, if we get a properly sized disposable MERV 8 or 11 filter, that air

and particulates can't just scoot

> around the edges and into the system?

YOU'RE RIGHT ABOUT THE FILTER NEEDING TO FIT

TIGHTLY. MOST WILL BE SUCKED AGAINST THE

SURFACE SO A WEATHER STRIPPNG MATERIAL

WOULD HELP. JUST MAKE SURE YOU DON'T REACT

TO IT. THE APRILAIRE DOESN'T HAVE THAT

PROBLEM BUT, AS NOTED ABOVE, IS MUCH MORE

EXPENSIVE.

Carl Grimes

Healthy Habitats LLC