9,184 posts, read 18,506,347 times 12,214 posts, read 13,180,715 times Originally Posted by motifone If you have a furnace filter, it wont be on the condenser outside. It will be in the unit in the attic.Your window unit could make you sick. Before you install a window air conditioner in a room, consider some of the harmful effects it can have. Mold, for example, can be worse in a window unit than a central AC system. Other possible problems apply to air conditioning in general, not just window units. Respiratory Illness Window unit air conditioners work by drawing heat and humidity from the room to lower the ambient temperature. The dehumidifying effects can also cause some drying of the mucus-coated lining inside your nose and allow airborne viruses to enter your system. A study published by the International Epidemiological Association in 2004 found higher sickness rates attributed to upper respiratory illnesses in women working in air-conditioned offices as opposed to women working in offices without air conditioning, though results were considered preliminary, due to limitations of the study's data.

Allergy Irritant The humidity the window air conditioner draws from the air doesn't magically disappear; it deposits on the cooling coils inside the unit. This moisture plus dust creates an attractive environment for mold-growing spores. Failing to remove and clean or cover the window unit during the winter allows the accumulation of mold inside the cabinet. Neglecting to clean the filters inside the unit or installing inferior filters can allow dust and debris to pass through it. Breathing these mold spores can trigger allergy symptoms, such as coughing, watery eyes and a runny nose. Mold can also trigger breathing restrictions in asthma sufferers. Inspect and clean the coils as needed. Outdoor Air Infiltration A high-quality window air conditioner that's properly installed should not permit unfiltered outdoor air into the interior space. However, any breach in the seal between the air conditioner unit and the window can introduce outdoor air, along with allergens and other air pollutants.

Additionally, a malfunctioning or poorly designed air conditioner may not filter outdoor air sufficiently, pulling outdoor air directly into the room. To prevent these problems, make sure the air conditioner unit is fully sealed around the window opening and the unit is designed to filter all conditioned air. Also be sure to use a high-quality filter or supplemental disposable filter in addition to the unit's standard filter, to remove as many air pollutants as possible. Irritate Exiting Eye Conditions The allergens blown into the air by your window unit air conditioner can worsen allergic conjunctivitis, also known as Pink Eye. An inferior filter allows dust mites and animal dander to pass through the window unit’s blower and pollute the air. These allergens irritate the lining of the eye, turning it pink or red. Air conditioning can also increase the suffering of individuals diagnosed with blepharitis. The cold air blowing into the room can accelerate tear evaporation and aggravate sufferers’ dry eye symptoms.

Environmental Hazards Both window unit air conditioners and central units use refrigerant to cool your room. Depending on the age of the unit, it could use chlorofluorocarbon cooling agents that could leak from the sealed system and damage the earth’s ozone. Improper disposal of these older units could result in fines up to $25,000 issued by the Environmental Protection Agency. Even units using hydrochlorofluorocarbon cooling agents can harm the environment, although not as damaging as those units using chlorofluorocarbons. ac unit motor priceCheck with your municipality for disposal facilities before you throw away your leaky unit. ac unit temperatureReferences The New York Times: Really? best central ac filtersThe Claim: Air-Conditioning Can Cause ColdsCardiff University: Summer ColdSharecare: How Does My Nose Protect Me from InfectionsIEA: Workplace Air-Conditioning and Health Services Attendance Among French Middle-Aged Women: A Prospective Cohort StudyCalifornia Energy Commission: Window Air ConditionersHello Daily News: Air Conditioning: Too Cool To Be Good For You?

Filters in all return vents? Re: Filters in all return vents? Originally Posted by joverholser No good call and I agree ... Originally Posted by jfunderburk Washington State Licensed Home Inspector # 221 President, Washington Association of Property Inspectors (WAPI) (253) 241-0602 calls answered until 10pm Puyallup Home Inspectors - Olympia Home Inspectors Pierce County -Thurston County - King County - Snohomish County Originally Posted by sstanczyk That's what I do. I can easily change the filters at the return. My whole house filter is in the crawl. Where there is a Will there is a Way! Infraspection Institute Certified Infrared Thermographer Level I # 9631 "it's not just about how to turn on and tune the camera to make pretty colored spots!" David A. Andersen, Woodlawn, TN completely clogged with a thick layer of dust. Apparently they were working. Professional Certified Master Inspector In Edwardsville, Glen Carbon, Godfrey, Maryville,

Fairview Heights, O'Fallon and surrounding areas of Illinois Metro-East Re: Filters in all return vents? I have a Lennox G40UH(X) series furnace, which is installed in our attic (We have a single-story house on a slab). Because the furnace is installed in the attic, it is "laying down" on its side, and the incoming air is piped into what would be the bottom of the unit if it was standing up. We have intake vents in almost every room of the house (small vents, about 12" long by 8" tall). These vents go up to the attic, and they're all routed into a big metal box which is appears to be welded to the bottom of the furnace. Because this is kind of hard to imagine, I mocked up a little image of my setup (this isn't my actual furnace, just a similar picture I found on Google): I have flexible ducts leading to the cold air intake "box" that is welded to the bottom of the furnace, and round flexible ducts leading from the hot air "box" to all of our vents (which are in the ceiling).

The problem I am having is that I can't see where to install a filter! I can remove the front panel and see the bottom motor, but there's no where to actually put a filter. According to the User's Information Manual: This unit is not equipped with a filter or rack. A field-provided high-velocity filter is required for the unit to operate properly. A filter must be in place whenever the unit is operating I don't have any idea what a "field-provided filter" is. When we bought the house, there were a few destroyed filters in the attic next to the furnace (all of different sizes, a few cut to different sizes, but no filter in the furnace. It looks like the previous owners had no idea either. So, for now, we've just been running the furnace without any filter. Is there something I can do to put a filter in? Is it really harmful to run the furnace without one? Should I look into putting filters in all of my little air intakes around the house? Update: As is usually the case with me, I put off worrying about the furnace until it started getting too cold here at night.

I finally climbed up to the attic and took a good look at the furnace. There isn't any indication of where a filter should go, and no slot to slide it in or bar to hold it in place. This is the air intake area - you can see the circulating fan on the right, behind the control board: I put the filter along the bottom - a 14x25x1 fit snug across the whole side (bottom if it was standing up). I had to fold and bend the filter some to get it inside the furnace. The only thing that seems to hold it in place is the body of the circulating fan: hvac furnace attic air-filter lennox I have the same filter location as referenced by Steve Armstrong. There is no slot for the filter but it is just held in place over the return duct by a metal arm. Here is the opening between the return and the blower: And here is the filter in place over that opening with the metal arm holding it in place: I would not have known a filter was supposed to go there if there hadn't been one there already.

Usually the filter is mounted between all the return ducting and the furnace itself - potentially it is installed at a strange angle or covered up with tape or something. Here is a picture of mine, it's the darker colored piece the duct is attached to, with foil tape sealing it to the furnace housing. I don't know if this is common or not, but in our current house and our previous house, the filter is in the return vent inside the house. The vent grate has two little latches that allow it to swing out of the way, revealing the filter. To check if yours is like this, just look for the latches and/or look through the vent slots and see if you see a filter. Edit: I should have read your post a little more carefully, I didn't notice you mentioned "all my little air intakes." So clearly you don't have just one return vent that could be housing a filter. At any rate, if a filter were present it would have to be between the return box at the left of your diagram and the unit itself.

The installer should have built a gap in there to accept a filter, just like in gregmac's photo (but preferably this would be a slot rather than needing to be taped in!). If you're not seeing something like this I'd recommend modifying it, or having someone do it if you're not comfortable doing it. Sounds like the unit doesn't hold the filter. It must be custom installed right between the return duct and the unit. You'd think the hvac guy would leave some kind of access panel. Mine is just like @gregmac's picture, except I can get at the filter on the opposite side via the blower access panel. Your going to circulate a lot of dust without a filter. At my old house, there wasn't a slot to put the filter into. Taking the door off the side showed me the motor, like you've said, which was situated inside the cold air return chamber (much like your picture). The filter rested on two notches on the outer edge of the chamber, and basically blocked my view of the motor. See if there's a way to place the filter "in the way" of the cold air as it passes the motor.

This disgusting image shows how the door opens to reveal the motor, and the air filter is placed at an angle in the way of the motor. Air flows from above and hits the angled filter. You need to install a return air grill designed to have an air filter installed. This is much more convenient and more likely to get changed as a result. The placement of a filter in the unit in an attic is not a wise choice. It sounds to me like the 'return vents' are actually exhaust vents from the heater. My attic heater has a return duct directly below the heater at floor level in the living room. The filter is in front of this return duct (20" X 30" filter). There should be a rather large flange on the bottom or side of your heater for the return duct to attach. It sounds like your heater is sucking in cold air from the attic and heating it instead of sucking in the already heated air in your house for recirculation. An expensive way to heat a house. Page 28 of the installation manual (PDF) says this: