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Furnace Filter


Furnace Filter Replacement

What is a furnace filter? 

A furnace filter is a special kind of material use with the system to filter air before it passes through the furnace. These filters are made in different size, shape and colour for customer to choose from.

The air inside our home can be harmful to our health. This is as a result of our environment and the use of different types of cleaning chemicals. Some of these are pollen, dust, debris, dirt, spray paint dust, clothing fibres, carpet fibres, clean chemical, fabric softener and bleach . These are all base on climate, season and natural disaster. Therefore, it is very important to have the correct size filter with the correct MERV rating, in order to receive optimum performance. 

What is MERV?

The meaning of MERV is Minimum Efficiency Reporting Value, which is a scale use by ASHRAE group to rate the effectiveness of air filters. Choosing the right MERV for your filter will help with the filtration of air throughout your home. This means, the higher the number, the better the air will be filter. Customer should never choose filter with a very high MERV. Why? Because this can also be harmful to the furnace. Note: Even though higher MERV result in better filtering, it will restrict the air passing through the furnace. This can cause your furnace to operate higher than normal, less efficiency, and in many case, shutting down the furnace on high temperature.  

MERV Ratings Value (From 5 to 20):

5-8 Mold spores, dust mite debris, cat and dog dander, hair spray, fabric protector, dusting aids, pudding mix
9-12 Legionella, humidifier dust, lead dust, milled flour, auto emission particulates, nebulizer droplets
13-16 Bacteria, droplet nuclei, cooking oil, most smoke and insecticide dust, most face powder, most paint pigments
17-20 Virus, carbon dust, sea salt, smoke


How to install a furnace filter?

Customer should always be aware or familiarize themselves with the direction of furnace air flow. This is important in order to properly install the filter. Manufacture makes it easier for anyone to install filters, by use arrows. These arrows indicate how the filter should be install, according to the air flow of the system. In some case, customers can observe the placement of the old filter and install the new filter in the same position. It is the responsibility of the Furnace contractor to explain to the customer where to install the filter. Customer should pay close attention to the size filter. This number will be written on the top or on the side of the filter.

Furnace Filter installation

How long before I replace my filter?

The most commonly use filter in homes are 16x25x1, 20x20x1, 20x20x4 and 20x25x4. Furnace manufacture generally recommends all one inch filter be replace every month. However, most filter manufacture recommends one inch filter to be replace within 90 days. But for 4 inch deep filters, these should be replaced every 6 months. Customers should always pay close attention to there filter during system operation. Note however, the replacement of your filter depends on the usage of your furnace systems. Homes that are closer to construction site, busy roads and industrial factories, will have to replace their filters more frequently.

Different types of furnace filter.

There are many different types of filters being produce by manufacture. These are base on customers, homes, businesses, job applications, industry and other requirements. Customer should always buy filters base on there needs and application. 

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