Air Cleaners

Benefits:
· Control dust and dirt in the home
· Save energy
· Avoid equipment breakdowns
· Extend equipment life.

The Skinny On Filters
There are trade offs with all air filters. We are talking performance, convenience and money. Performance includes two factors – how well does the filter clean the air – and filters are tested to the industry standard ASHRAE dust spot test – and the one most homeowners are not aware of – pressure drop. Pressure drop is just another way to describe resistance to air flow. That’s right, some filters do a great job of filtering the air, but create too much resistance to the flow of air, causing system performance problems. Problems like high energy consumption, lack of comfort and equipment breakdowns can all be caused by lack of proper air flow.

Imagine what a great filter a piece of sheet metal would make installed in your ductwork – not much dirt would get through it! And of course air flow would be compromised. So be careful when selecting a high efficiency filter – make sure your air flow will not be negatively affected. Apple Heating can help you select a filter that will provide high efficiency air cleaning without creating air flow problems.

Types Of Filters:
· Fiberglass “rock stoppers”. These filters main benefit is cost. They are inexpensive and do a lousy job of cleaning the air. 5% efficiency rated. Should be changed every 4-6 weeks during season.
· Foam filters are better than typical fiberglass “rock stoppers” that are commonly used. They are higher in efficiency rating – 5-10%. Should be changed every 4-6 weeks during season.
· Pleated filter – 1” thickness. These filters use a pleated paper media that captures a much greater amount of the airborne particles that it encounters. Rated at 15% efficiency in ASHRAE dust spot test. Care should be taken not to hinder air flow. Should be changed every 4-6 weeks during season.
· Extended Surface Media Filter Common brands are SpaceGard and Air Bear. These filters have a much greater surface area, and therefore have a longer change interval as well as a lower pressure drop than the above filters. These media filters are rated at 25-50% efficiency in the ASHRAE dust spot test in initial (clean) tests. They get more efficient as they get loaded with dirt and dust. Be sure to use as designed – larger systems require 2 or more filters to maintain pressure drops at higher air flows. This filter costs a little more but it does a great job of filtering the air, and it is convenient – change every year for heating/cooling applications, every two years for heating only.
· Electronic Air Filters These filters are more effective at removing the smaller particles in our air - over 94% of particles .5 microns in size or larger. A human hair is about 100 microns in diameter. Electronic air cleaners are rated at 70% efficient in the ASHRAE dust spot test - initial test. They are very effective against very small particles (like tobacco smoke) when they are clean. These high efficiency air cleaners use the same technology as that in commercial "smoke-eaters" commonly found in restaurants.
The technology is simple - a wire is charged with an electric current, which adds a "charge" to the particles as they pas by the wire. Then the charged particles are collected on a plate that has the opposite charge. As the plate gets dirty, however, the efficiency goes down. If these type of air cleaners are neglected, they do a poor job of cleaning the air. But when maintained properly they are a terrific air cleaner. Operating cost is less than that of a 40-watt light bulb. And there are no replacement filters to buy.
· Combination Media/Electronic This filter is perhaps the best filter available for the average homeowner. We would recommend this as adequate for nearly everyone, the exception being folks who have a person in the home that has a serious respiratory problem (for those systems a HEPA air cleaner provided an even higher level of air cleaning). The Aprilaire 5000 whole house air cleaner combines the electronic air cleaner with the media air cleaner. This unit has the high efficiency of the electronic air filter with the performance of the media air cleaner, providing the best air cleaning available. These filters are installed in the return air ductwork, usually just before the equipment.