Furnace Filters Tucson AZ
Monday 24 Hours
Tuesday 24 Hours
Wednesday 24 Hours
Thursday 24 Hours
Friday 24 Hours
Saturday 24 Hours
Sunday 24 Hours
AC Unit Installation, Boiler Installation, Central AC Installation, Furnace Installation, Heat Installation, Heat Pump Installation, HVAC Contractors, HVAC Maintenance, Water Heater Installation
Service Types and Repair
AC Unit, Boiler, Central AC, Furnace, Heat Pump, Heater, Water Heater
Choosing the Right Furnace Filter
There are plenty of choices when it comes to replacing the air filters in your home comfort system. A visit to a home center may produce a half dozen or more different filters that could be used, ranging in price from 49 cents to $15. Their effectiveness varies widely, too. So which is the right one? The primary reason for a filter in your furnace is to protect the equipment. Heavy dust on the blades of a blower can throw it out of balance, causing vibration, wear and noise, and dust on the fins and coils of the system can reduce the efficiency of heat transfer. While a filter is relatively inexpensive to replace, the cost of not replacing it may be a lot higher. If a cooling coil is blocked with dust and lint, for instance, it can cost $250 or more to remove it for cleaning. The other big reason to keep your filter clean is your health.
A 1999 Mayo Clinic study found that mold is the culprit in most chronic sinus infections, and the presence of dust, pet dander and other pollutants can aggravate health problems. With all the options available, selecting the right filter can be confusing. The American Society of Heating, Refrigeration and Air Conditioning Engineers has tried to simplify things by devising a rating system called the Minimum Efficiency Reporting Value, or MERV. The MERV shown on the packaging of most filters is based on their ability to capture particles larger than one micron (slightly less than 1/25,000 of an inch). It is designed to represent, with a single number, the performance of the filter over a large range of particle sizes. These values range from one to 12, with the higher number capturing more dust.
A second system - the Filter Performance Rating, or FPR - is primarily used by 3M Co., a major maker of filters. It is based on the ability of the filter to capture particles from 0.3 to one micron. These sub-micron particles are the ones most likely to be inhaled, where they can cause breathing problems. The rating of filters in this system range from 300 to 1600; again, the higher the number, the greater the filtering ability. Filters are rated when they are new. As they accumulate particles, the spaces between fibers in the filter become smaller, allowing them to trap progressively smaller particles.
A filter can be thought of like cheese - the older it gets, the better it gets, until it gets so good you have to throw it away. I have found fiberglass filters, which are among the least efficient, plugged with dirt so solidly the system shut down because it could not pull enough air through the filter to keep the furnace from overheating. In one case, the suction from the furnace fan against the filter was so strong the cardboard frame buckled and the filter was sucked into the ductwork, which had to be taken apart to remove it.
In general, filters should be changed at least every three months. Some types of filters may need washing or replacement more frequently. Factors that may shorten filter life include dirty ducts, construction, house pets and the presence of smokers. The filter should be checked monthly until the appropriate interval has been established for your house and lifestyle. The choice of filter depends on its purpose. The least expensive (and least effective) filter uses a fiberglass or cellulose pad, usually held in a cardboard frame. It is capable of protecting the equipment by catching most of the larger dust particles that tend to block heating and cooling coils, but will not remove the fine particles that tend to cause allergic reactions. The next step up in efficiency is a washable/reusable filter. It also uses an essentially flat pad, sometimes of plastic and sometimes of metal foil shapes. These filters usually have a metal or plastic frame and can be washed with a hose and reinstalled.
Some of the metal filters can be sprayed with a tacky coating material to increase their ability to catch small particles. They should be washed monthly and may last three to five years. A pleated polyester filter provides more filtering capacity than a flat filter, and many are made with fibers that have a permanent electrostatic charge to attract small particles. The life of these filters is about three months in most houses. There are a few plastic filters on the market that claim to produce an electrostatic charge from the air flowing through them.
These are seldom more effective than standard filters and are significantly more expensive. As more and finer fibers are added, the ability to trap sub-micron particles increases. However, the density of the filter causes more air resistance than coarser filters and may require a different or larger fan to pull enough air through them. The density of the filtering material must be balanced with resistance to airflow. The design of energy-efficient heating and cooling systems must balance these factors carefully.
If you have allergies or other problems related to indoor air quality, even better filtering systems are available. The deep-pleated, high-efficiency mechanical air filters are about the same size as ordinary filters but are 4 to 6 inches thick. They do not fit in standard filter holders and require a special box to be built into the duct system. The filter element is a pleated paper unit, similar to the one in the air cleaner of an automobile. As much as 80 square feet of filter material is contained in these filters. Again, electrostatically charged fibers can be used in the filtering media. These filters can remove particles as small as tree pollens. They should be effective for at least a year, and possibly as long as two years. Replacement filters are in the $25 to $30 range. The ultimate in residential air filters is the electronic filter. It is about the same size as the box for a deep-pleated filter and requires electricity to operate. The air is directed through a high-voltage grid that applies a positive charge to any particles in the airstream. These particles are then attracted to a negatively charged element. These elements should be washed every month or so and the elements reinstalled in the filter. This type of filter can remove particles as small as smoke. The time between washing can be extended by using an inexpensive filter ahead of the electronic unit.