Page 37 - November 2015 Green Builder Magazine

Exteriors / Roofing / Structure / Insulation / IAQ / Windows / Heating / Lighting / Appliances / Faucets & Fixtures / Finishes / Cabinets & Tops / Alternative Energy

non-HEPA filter may simply toss tiny particles back into the air. SCHOTT ROBAX 35
A whole-house vacuum solves this problem by actually taking Fire-Viewing Glass
unwanted particles outside the living space—into a garage or www.greenbuildermag.com 11.2015
unfinished basement. Used on fireplaces and stoves, SCHOTT
ROBAX glass-ceramic panels give
SPOT VENTILATION homeowners a view of the flames,
Local Management while protecting them from flying
Chronic moisture can lead to mold growth. Exhaust fans excel sparks. The panels also make optimum
at removing excess moisture that tends to build up in specific use of energy through targeted
locations, such as bathrooms and kitchens. Kitchen range hoods regulation of incoming air and flue gas.
also remove cooking contaminants. These fans have become quite http://bit.ly/1Sj1j6z
sophisticated and quiet; some manufacturers such as Panasonic of-
fer “smart” models that adjust to changing moisture conditions, or AirCycler G2K Whole-House
that can sense when a room is occupied. Whole-house exhaust-only Ventilation System
ventilation systems exist, but be aware that these rely on cracks
and penetrations in the building envelope to supply the makeup The G2K system integrates with an
air that replaces the exhausted air. In tighter homes, this can cre- existing HVAC system and combines
ate “negative pressure.” In general, we recommend using exhaust the advantages of central fan integrated
fans to supplement balanced whole-house ventilation systems. supply and whole-house exhaust fan
ventilation systems. It includes the
What Makes One Carpet AirCycler g2 furnace fan timer, FanConnect bath/fan light switch with
Greener than Another? remote fan control and a motorized fresh air damper, available in four sizes.
www.aircycler.com/pages/g2k
The EPA offers a few guidelines:
■■ Low or no volatile organic compounds (VOCs) ENERGY AND HEAT RECOVERY VENTILATORS
■■ No toxic dyes Key Component
■■ Recyclable You may have heard of energy recovery ventilator (ERVs) and
■■ Recycled content their northern cousins, heat recovery ventilators (HRVs). This
■■ Reduced energy use (during manufacturing) heat transfer technology is a key component of any modern
■■ Reduced or improved air emissions (during manufacturing) “tight” house. Without them, modern houses would probably
■■ Minimum 10-year warranty not be worth the foam, tape and caulking with which they’re
sealed. These mechanical wonders take hot, unconditioned fresh
Recent EPA research found that carpet tiles can be a more air from outside, pass it over a heat collecting medium, where it
sustainable alternative than wall-to-wall products. If you stain a gets a partial cool-down before entering the home. A study by
section, for example, you can remove and replace it. Also, you can John Bower (visit www.healthyhouseinstitute.com) found
“rotate” tiles from heavy use areas to light use areas. The EPA’s test that using a heat recovery ventilator with continuous ventilation
building used Milliken 36” x 36” tile carpet and low-VOC adhesives to cost a Minnesota homeowner just $86 a year. It cost $188 to do
test these principles. the same ventilation without an HRV. GB

Ventilation Air Requirements (CFM) Fresh Air Formula

Floor Area (ft2) Bedrooms >7 Indoor air tends to concentrate pollutants quickly.
Less than 1,500 0-1 2-3 4-5 6-7 90 As a result, building codes typically have certain
1,501-3,000 30 45 60 75 105 requirements for the amount of fresh air that must be
3,001-4,500 45 60 75 90 120 exchanged with stale indoor air over a given period.
4,501-6,000 60 75 90 105 135 Typically, this is expressed as cubic feet per minute,
6,001-7,500 75 90 105 120 150 or CFM. An organization called ASHRAE provides
Greater than 7,500 90 105 120 135 165 guidelines for how much ventilation is needed, although
105 120 135 150 the best means for achieving that ventilation are often
debated. When in doubt, more ventilation is better than
less, but you have to balance the resulting energy loss
with improved indoor air quality.
-Editor

SOURCE: ASHRAE 62-2-2003