It is not too unusual to find missing or out of place furnace filters----or even non-functional Electronic Air Cleaners. All furnace filtering systems need to be maintained and even more important they need to be there! If they are not there at all, the same old air keeps circulating through the heating and cooling ducts. When not present the supply ducts will get very dirty and the dust will circulate back into the home. If you have air conditioning and/or heat pump components installed, the coils will become very clogged with this dust----making the unit inefficient or not functional at all. Re-circulating this dusty air into the home works against most people’s distain of dusting. Home inspectors in Seattle should always check furnace filters. Take a look at this furnace installation. The blue highlighted arrow shows the flow of return air to the furnace as it arrives at the Electronic Air Cleaner. With the Air Cleaner access cover removed we can see that the internal components of the filter are missing (pre-filters and Electronic coils). The orange high-lighted area is the opening into the furnace plenum below the blower area of the furnace above. That space left of the orange highlighted areas would normally be the location of the electronic coil components of the air cleaner. What makes this installation “unusual” from what would otherwise be a very common place defect found in many heating systems, is the presence of another air intake that is the wrong side of the filters----that aren’t there. This next picture----high-lighted in green shows that return air intake that goes through the plenum to an adjacent space. So even with all the proper components in place and well maintained, this air intake would likely be the major source of unfiltered air to the heating/cooling system. How dusty is your house? Charles Buell Seattle Home Inspectors, ASHI Home Inspector, Structural Pest Inspector, Charles Buell Inspections Inc, Seattle, WA
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Mr Charles,
My family, species, has a built in duster.
Nutsy
So beat the dust our of here Nutsy:)
Hi Charles:
Excellent information in your post! I can't imagine anyone would be a fan of having to dust constantly at the very least I know I'm not! Thanks!
:)
Matt
This reminds me of the foreclosure house I just toured with my clients. It was filthy! Every air vent looked like it had never been cleaned in it's 11 years of operation.
Thanks Charles. Now I have yet another phobia I'll have to receive therapy for!
I'm going to go dust my air flow filters right now!
That furnace doesn't look all that clean or new either. So who did the the second return, home owner or pro?
Matt, and yet you would be amazed at how often filters are only partially in place.
Lizette, yup---seen them too
Craig a new book title perhaps? "Does your inspector make you crazy?"
James, yes the furnace was trash---no clue on when it was done---might have been that way for 21 years:)
And I'd love to see your opinion of those "washable" filters that have holes bigger than Nutsy's tail...
This one was hard for me even with all those beautifully colored pointers. Somewhere I got lost. Seems that every system has a different place for a filter.
Shoshana, lots of the washable filters do seem to have bigger openings. The "pre-filters" in the Electronic filters do and are only mean to collect larger debris than can be "zapped" by the electronic coils.
Barbara, the filters do get located in a lot of different places depending on the configuration of the ductwork etc.
Often I see second returns without filtration. What are they thinking?
Jay, less effective than riding down the road with the AC going full blast and the kids have the windows all the way down in the back:)
Anyone can do that stuff, right? You don't need a pro. Cut a hole and instant return air.
Jack, I wish it was a "guarantee":)
Charles,
We are finding more and more homes that look like this - typically, the filters are out of sight/out of mind and are not a priority when the homeowner is facing foreclosure. More and more of our local home inspectors are bringing this up in their reports.
Great post.
Vince
Thanks vince