I want to install a central vacuum system because of my children’s allergies. Should I vent it outdoors even though it will suck air out of the house? Are more powerful models best even though they use more electricity?—Kim H.
A central vacuum cleaner is probably your best vacuum system option for removing allergens. Even though small portable, but powerful, canister vacuum cleaners have high-quality HEPA filters, the exhaust air and internal leaks will still release very fine particles into the air.
I have allergies and I use a central vacuum in my own home. A good quality HEPA canister vacuum still comes in handy, though, for quick cleaning of small areas.
If your primary concern is removing allergens, then venting the central vacuum cleaner outdoors is certainly an option, but not necessarily the best. Doing this will draw heated or cooled air from inside your home. This will increase the load on your furnace and air conditioner, increasing your utility bills.
When the conditioned indoor air gets drawn outdoors, it is replaced by outdoor air leaking in through cracks around windows and doors, the foundation, etc. The outdoor air that gets drawn in may contain more allergens than were in the indoor air initially.
Unless you have a heat-recovery ventilation system with an enthalpic heat exchanger, humidity is also drawn indoors with the outdoor air. This may exacerbate allergies from indoor sources.
With the multi-stage filtration systems that most central vacuum systems have, indoor venting is usually preferable. Some of the manufacturers offer units, such as Beam’s Serenity Plus, with extra soundproofing, exhaust filters, and mufflers to reduce noise. Utility rooms and basements are common locations for the central power unit.
Mounting the power unit in an attached garage is also an option. Although this still draws conditioned air out of the house into the garage, it will moderate the garage temperature. Since it has common walls with the house, it is not a total loss of energy.
More powerful models have greater cleaning power, so they are generally your best choice if you can afford their higher prices. A more powerful one will clean faster and more thoroughly, so the additional electricity used is offset by less running time.
The cleaning power of any vacuum is measured in air watts. The manufacturers combine the airflow rate (cfm—cubic feet per minute) and the suction (inches of water column lift) to determine the air watts. Air watts for central systems range from about 400 to more than 900. If you cannot find the air watts rating for a system, the cfm airflow rate is the next best measurement.
It is possible to install a central vacuum system yourself, but most people have one installed by the dealer. The systems use PVC piping. To obtain the maximum cleaning power at each inlet, plan the piping to minimize its length and the number of bends and elbows.
MD Manufacturing has an optional remote electronic control system, which eliminates the need for the low-voltage wiring to each inlet. This simplifies installation, eliminates future broken wire problems, and makes it compatible with automated home systems.
The following companies offer central vacuum cleaners: Beam (800) 369-2326, www.beamvac.com; Electrolux (800) 896-9756, www.electroluxusa.com; Eureka (800) 282-2886, www.eurekaco.com, MD Manufacturing (800) 997-2278, www.builtinvacuum.com; and Nutone (888) 336-3948, www.nutone.com.
Mail requests and questions to James Dulley, Kentucky Living, 6906 Royalgreen Drive, Cincinnati, OH 45244, or visit www.dulley.com.