What is a furnace filter?

Question

I think this is another UK/Us language confusion --- we call furnaces boilers - but most are gas fired, producing hot water - not hot air - this has been fascinating!

Answer 1

The forced air furnaces I have seen have a fan that pulls air from the house through whats called cold-air ducts. It continues to pull the air through a filter in an attempt to remove dust before the air enters the actual furnace. The fan goes on to push the air through the furnace where it is heated and continues to push the air through the warm-air ducts and on into the house.

The typical filter is maybe 20x20 inches and around 1 inch thick. There are lots of different sizes as you can tell by going to a hardware store and asking to see their furnace filter aisle.

You should replace your filter every 2 months or so otherwise it gets filthy enough to lower the airflow enough to first make the furnace less efficient than it already is and eventually make the furnace hotter than it should be while not heating your house very well.

If your asking what it is I'm guessing you haven't replaced yours in a while. You should turn your thermostat low - so your furnace doesn't come on - then go to the furnace, look around for a door or cover over the long slot the filter is in, pull it out to see how dirty it is and to get its size. Then go to the hardware store and get a middle of the price range filter (maybe a couple so you have your next replacement). Put it in while noting the "direction of airflow" arrows which should be pointing toward the furnace.

Once you set your thermostat back you might notice more airflow although, since the air is moving faster with less restriction, it might not be a warm as it was with dirty filter.

Answer 2

A furnace filter is a removable filter that is located between the air intake and the furnace motor. The purpose of this filter is to stop airborne particles and dust from entering and producing damage to your furnace. Typically manufactures use the standard Fiberglass Furnace Filters, but others use the washable furnace filters, which we do not recommend, they just let too many particles through the filter. We recommend our Flanders EZ Flow Filters. After the primary job of protecting the motors of the furnace from dust, it also will help improve the efficiency by increasing the airflow. Without using a filter, the furnace would get clogged from the dust and debris, which in turn, will make the furnace work harder and probably break down, this is the basic reasons for using furnace filters. Although, originally used to protect the motor of the furnace, furnace filters have come a long way and have been redesigned to take into consideration more environmental issues in today’s market. Furnace filters are able to improve the indoor air quality by trapping dust, dirt, debris, pollen, smoke, etc. In order to maintain your furnace system and at the same time improving your indoor air quality, we suggest you should look at a higher quality furnace filter such as our Flanders Polyester Filters. Fiberglass has been used in AC or Furnace Filters of the same type that has been protecting furnaces and central air conditioners. The filtering media is continuous filament spun glass. A resistance bonding agent provides rigidity and resistance to media compression. UL marking appears on the filter frame. These filters have been tested by Underwrites Laboratories Inc. and classified as UL 900 Class 2 for flammability. If this is a concern, you can choose our Flanders Polyester Filters.

Answer 3

It's a filter in your furnace to keep your furnace clean...if you haven't replaced it in a while, you should could make your furnace more efficient, ask a friend to help...not that hard! Good Luck!

Answer 4

It's a good idea to clean it regularly - check furnace or manual for how often. I used to clean ours about every 2 weeks; plenty dust in that time. Detailed guide at ehow.com

Answer 5

it filters the dirt that comes out of the furnace

Answer 6

a device that filters a furnace. pfft