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Indoor Air QualityFiltration • HumidityFiltrationA major advantage of forced air systems is the ability to filter air in addition to heating or cooling it. A number of filtration options exist. We will gladly review the options with you to choose the system that best meets your needs of efficiency, cost, and convenience. The typical washable or throwaway type filter that comes with the furnace is usually satisfactory for larger lint particles and animal hair, but does little for pollen, animal dander, dust mite residue, mold spores, and other fine household dust. Many of these fine particulates stay airborne until they stick to the walls, furniture, or draperies, or until they are breathed in by the building’s occupants. The simplest way to modestly improve indoor air quality is to replace the standard washable or throwaway media filter with a pleated filter. These will catch most of the visible dust and are several times more efficient than the standard filter. Our service department uses these pleated filters to replace existing standard throwaway filters when performing equipment maintenance. Extended pleated media filters, such as the Lennox PMAC or Aprilaire 2400 provide even greater efficiency at a modest additional cost. These are very effective against pollens and dust particles 3 microns or larger. The media needs replacement only once a year, and the initial installation cost is low when replacing heating and air conditioning equipment. Electronic air cleaners are even more efficient than the typical extended media filter. There are no consumables, but the cells should be washed every few months to maximize effectiveness. These operate by ionizing particulates while they flow through the system. A series of collector plates with several thousand volts of static charge then precipitate the ionized particulates, leaving very clean air returning to the living space of the home. The Aprilaire 5000 electronic air cleaner is a hybrid between the traditional electronic air cleaner and the convenient extended media air cleaner. A charging grid ionizes particles that are drawn very efficiently to a grounded media. These boast some of the highest efficiencies in the industry. HEPA filters are sometimes requested for non “clean room” applications such as residences. Although these have an extremely high efficiency rating (99.97%), they contribute too much resistance to air flow to be attached directly in the air stream of a typical ducted system. The HEPA systems use separate filter/blower cabinets that bypass about 50% of the airflow to be cleaned and returned to the air stream. Not all air contaminants are in particulate form. Odors and chemicals such as pet odors, cooking smells, perfumes, tobacco smoke, chlorine, cleaning supplies, paints, and solvents cannot be removed by particulate filters. Bioaerosols such as bacteria, viruses, molds, spores, and fungi are not necessarily removed by these filters either. The Lennox PureAir™ air purification system combines a MERV 9 pleated media filter, UVA lights, and a catalyst to remove the widest spectrum of airborne contaminants available in a residential system. All of the systems we have described here mount on the return side of any forced air heating and/or cooling system. For maximum effectiveness, the fan must be running all of the time. Modern thermostats feature a fan switch for continuous air operation. Some models allow you to program continuous fan operation during specified periods. Variable speed blower motors provide the quietest, most efficient air circulation for air cleaning. HumidityOur remarkably temperate Peninsula climate also gives us relative humidity that seldom goes outside of the comfort range. Relative humidity is the amount of moisture in the air relative to how much moisture air is capable of holding at the given temperature. Winter dryness in a home can be caused by an oversized furnace or excessively leaky ductwork. Either situation can result in greater infiltration of air into a home. When cold outside air is heated to a comfortable temperature, relative humidity drops to a level that is sometimes uncomfortable. If dryness is still a problem after correcting oversizing and duct problems, a humidifier can easily be added to most systems to bring a home’s moisture level to an acceptable level. We can help you choose the atomizing, bypass, or power humidifier appropriate for your needs. Some homes suffer from excessive moisture in the wintertime. This is usually caused by inadequate ventilation or water infiltration into the home from leaks or groundwater in the sub-floor area. An improperly vented gas appliance can also contribute moisture to a home, as well as potentially deadly products of combustion. Although “wet” houses require a thorough evaluation, the problem can often be solved by adding exhaust fans in the bathrooms, and using the kitchen range hood whenever the stove or oven is on (this is especially important when cooking with gas). Exhaust fans not only get rid of moisture at the source, they also cause the introduction of outside air into the home which, when heated, lowers the relative humidity inside the structure. We supply and install ventilation fans and ductwork for many applications. We also supply and install energy recovery ventilators where even greater ventilation is desired. For those who suffer from summertime humidity, the answer is air conditioning. Water is distilled from the air as it passes over the indoor cooling coil, delivering refreshing air with reduced relative humidity levels. Improperly sized cooling equipment can over-dehumidify the air, causing dryness complaints. Two stage cooling equipment is best for maintaining a comfortable balance between cool air and comfortable humidity levels. Duct Cleaning - Why We Don'tWe do not offer a duct cleaning service. Maintaining a filter on the return side of the heating and cooling equipment is generally all that is needed to keep the ductwork free of dirt buildup. Debris that might fall into a floor register is easily cleaned with a vacuum cleaner hose. Smudging around wall and ceiling registers is not caused by dirty ductwork, and is rarely caused by a problem furnace. Smudging is caused by the aspiration of air containing particles of dust that are merely being circulated by the forced air system, not being created by it. Improved filtration is the best way to avoid this problem. |
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