Reducing noise from electrostatic filter
Hi, smart people of Breaktime. We’ve lived in our green-built home for a year now and love it. The energy-efficient and healthful aspects of the heating system are wonderful— except the noise generated by our electrostatic filter. It is integrated into the heating system, right next to the furnace. It makes loud cracking noises, which is comforting in the sense that I know it’s one less particle of dust/allergen/bacteria getting into the house, but it’s annoying. There is a cold-air return duct in a hall space near the stairs on the first floor that transmits this noise to the whole house. What can we do to reduce the noise? I’ve thought of replacing the metal grate with a wooden one, but it seems that would offer minimal results. Any ideas? Thanks in advance!
Replies
Install a pre filter behind the return air grill.
One, it reduces the amount of dust to be zapped & it deadens the unadulterated zap of the electric filter.
How often do you clean the electrostatic filter plates ? It really should not make a lot of noise under normal operating conditions. The crackling is from large dust particles. Ours only starts to crackle if it gets pretty dirty. If I clean it about every 6 months, it hardly ever makes a sound. We do have a set of pre-filters before it. They look like the filters in your typical kitchen range hood and can also be cleaned.
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
It has made noise like that since it was new. It's worse when it first starts up in the fall, but we do clean it about every 6 months.
Does it have a pre-filter ? I dont think they are designed to work without one.Bill Koustenis
Advanced Automotive Machine
Waldorf Md
There is no filter at the cold-air return grill, if that's what you mean. It is hooked up in conjunction with a HEPA system and was installed by a mechanical guy who does all the systems for our green builder.
The cracking noise is arcing, and is only weakly related to the air-cleaning action. If you hear a lot of it there's probably something wrong, since arcing is basically "wasted" electricity -- electricity that isn't doing it's job to clean the air.
DanH: any idea what could be wrong? Our builders warned us that the unit would make noise, and we heard their own unit at their house. The cracks seem to come in spurts every few minutes or so, but there is no regular pattern.
It's been about 40 years since I dealt directly with one of these things, but lack of a prefilter would be one possibility. Otherwise the system may be misadjusted or there may be something lose or bent.
If your view never changes you're following the wrong leader
Furnaces and electrostatic filters are noisy when the return air grill is too close to either one. Relocating the grill far away will reduce the noise.
Electro-static filters and Forced air filters don' mix. The CFM's are too high. When the electro static filter catches dirt, it is immediately blown off.
We have that filter system in our house and I do know that you shouldn't be hearing that much snapping and buzzing from the filter. It means that you have some big dust bunnies between the electrodes arching, which creates ozone and will make burn marks on the elements.
I've also notices that if the fins and wires that make up the filter body can get tweaked with rough handling so that they are moved too close together, you'll get arching that way as well. Inspect it thoroughly so make sure all of the fins are parallel and the same distance apart.
We can often smell ozone coming through the heat vents. I thought this was normal—is it not? We have only handled the unit once, very carefully, so I doubt that the fins are messed up but will check.So to put a number on "not that much snapping", what is normal? A snap a minute? Less?
What I've said in the previous post pretty much exhausts my knowledge on the issue. Your manual or the manufacturer should be able to get you more guidance, but I will say that the unit we have (a Honeywell, I think) is pretty silent for 99.5% of the time.
Farm,
About the only time ours makes a noise is if we happen to bump into the cold air return and knock some dust loose. Other than that it is pretty much silent. Bill Koustenis
Advanced Automotive Machine
Waldorf Md
We have a Honeywell system in our house. 25 or so years old. Makes only an occasional snap ( less than once day). Has a pre filter of metal mesh like a kitchen stove fan. I clean the system about once a month.
If yours is noisier there is something wrong. (Or you have really dirty air with large particles) If a large particle gets into the electrostatic plates (dog hair) you can get a steady snapping and that arcing will erode the plate rapidly (guess how I know that).