never knew there was/is another filter in my 37 yr old central heating unit (in

[Joan M. W.]

i moved into this house in 1996 (it was built in 1976). The air conditioning unit is outside and the heating unit in attic. It has the vents in attic that lead to my three bedrooms, two baths, living room, kitchen, laundry room. Over the years I noticed no matter how many times I changed the filter in the vent in the hallway the house was constantly dusty. Over the years my bills were enormous but it was neither too cold or too hot. I kept asking my sons if there was another filter or if the vents needed to be cleaned. No responsible response. Truthfully I am now, nor have been in the past, been financially able to have it looked at professionally. That's why I'm trying to do this myself. My venting is taped together with what looks like duct tape which is coming loose...and I'm just stuck with what I've got. But the filter that MAYBE somewhere close to the unit in the attic, if it exsist, must be deplorable...after me living here for 17 years and not knowing. Can you help me locate the filter so I can see what I can do about it? I do not know what type of heating system it is or who installed it..

[trader4]

The filter is normally in the blower compartment of the furnace. Furnace typically has two cover you can remove. One is to access the burner compartment. The other to access the blower.

You don't say what kind of furnace it is, but if it's a gas furnace, at 37 years, I for sure would have it looked at by a pro. At that age, the heat exchanger could be shot, setting you up for possible carbon monixide posioning, etc. Too bad you couldn't get a home equity loan or similar. Back in 2010, with up to $1500 in fed tax credits, plus the typical state, utility, etc rebates, it was a great time to get a new efficient system.

[dpb]

There's at least a reasonable possibility there's a filter near the air handling unit in the attic, but if so one would hope there was/is provision to get there via a pulldown stairway or similar. It's possible they did put the filter on the return in the house.

It would be good to find where combustion air is from if this isn't all-electric. The upstairs old furnace here drew air thru a cutout into the attic and I discovered when we moved back it was almost completely blocked...

While things are tight, it really shouldn't be much actual cash to get a fall safety checkover and might well be worth it in reducing bills over the coming winter...

[Fat-Dumb and Happy]

If I were in your shoes I'd be getting a can or two of mastic and head up to the attic with a brush and putty knife. While you're up there slopping the stuff in and on the ductwork joints write down the model of the furnace and look it up on the internet to find if it might have a filter in the attic unit.

[Ralph Mowery]

That sounds right. The filter is not to filter the dust out of the house. It is to keep the dust from getting to the cooling or heating coils in the duct work.

I lived in a house and it got very dusty and the filters needed changing often as they were clogged with dust. Moved to another house and the filters last a long time before they seem to need changing, but I do change them every month anyway. They are cheep compaired to the problems a dirty filter can cause with the heat and air.

[DerbyDad03]

There's a company is my area advertising their duct cleaning service. They state that if you have to constantly dust your house, your ducts must need cleaning. "Run your finger along the baseboard. If it's dusty, have us come out and clean your ducts."

I don't recall if they specifically say that the ducts are the cause of the ducts, but they sure make it sound that way.

I feel like calling them and asking whoever answers to explain to me how ducts create dust. I mean, who doesn't have dust on their baseboards?

[krw]

Much of household dust is shed skin, particularly in the Winter.

[micky]

If the dust is getting out of the ducts, to land on your furniture, why do the ducts need cleaning? If the dust is stuck in the ducts, then cleaning would clean them, but the dust that is stuck there is not a problem anyhow. It just stays there.

If dust is coming out of the ducts, it must be coming, at some point, from the furnace, maybe from the air intake to the furnace, in other words, from your house. .

[recyclebinned]

Do you know if your evaporator might be dirty? The evaporator is the part that looks like a car radiator and would be located next to your air handler or furnace. Are you able to get a look at the surface of the evaporator that would be facing your heat exchanger or furnace?