Delos luxury lofts include air cleaning and treatment but IAQ is tmportant in every home (photo courtesy of Delos).
Poor indoor air quality is considered to be the fourth greatest pollution threat to Americans by the Environmental Protection Agency. A well-ventilated home, but not over-ventilated home, is based on many criteria, and can even vary between two production homes based on occupancy, furnishings, and lifestyle. Whether the homeowner is a master chef or a take-out king can impact ventilation requirements. Basic ventilation, however, simply maintains a good indoor air quality; it lessens air pollutants such as pet dander, mold, moisture, pests and VOCs (volatile organic compounds) emissions from furniture, flooring and even wall coverings.
New York-based builder Delos, incorporates good indoor air quality in all of the residences it designs under its “Living Well” brand, which combines luxurious style with the well-being of the occupants and sustainability. Delos created a “WELL Building Standard” and created the International WELL Building Institute to manage those guidelines. Actor Leonardo DiCaprio and holistic health expert Deepak Chopra are members of Delos’ advisory board.
Delos’ first “Wellness Residences” were completed in 2013 at 66 East 11th Street in New York’s Greenwich Village. The five loft-style condominiums include “75 wellness features and amenities,” including ventilation designed and integrated specifically for the needs of the homeowners. We’ve heard that DiCaprio was one of the first to buy the lofts, which include air cleaning and treatment practices such as particle filters, UV sanitation and activated carbon air filters, as well as continual air quality measurements that are tied to air changes and provide the homeowner with feedback.
Delos is providing funding to the Mayo Clinic to design, build and operate the WELL Living Lab, which will focus on research, development and testing of building innovations intended to improve health and well-being of the occupants.
The Environmental Protection Agency even has a label for homes designed and built to protect occupants from indoor air pollution. Indoor airPLUS homes protect homeowners from moisture and mold, pests, combustion gases, and other airborne pollutants, resulting in a home that is significantly more energy efficient than a home built to minimum code, helping reduce greenhouse gas emissions. The certification is tied to the agency’s Energy Star label, and a home must first receive that certification before going for the IAQ label. There’s even an app for builders who want construction specifications and a verification checklist.
Standards for Ventilation
ASHREA standards for residential ventilation were modified in 2013 to reflect tighter construction of new homes.
One of the biggest changes in the standard over the 2010 version was an increase in mechanical ventilation rates to 7.5 cubic feet per minute per person plus 3 cfm per 100 square feet. This is due to the earlier removal of the earlier default assumption regarding natural infiltration. The Standard 62.2 Committee had previously assumed homes got a minimum of 2 cfm, per 100 square feet, according to Don Stevens, committee chair.
Of the four types of ventilation (intake, exhaust, balanced, and ERVs/HRVs) the type you install depends on the climate in which you’re building, and the investment you want to make. Green and Passive House standards call for certain types of ventilation, and the Asthma and Allergy Foundation of America provides guidance on the integration of building techniques, materials and systems in its certification program.
Ventilation requirements for certification by the Passive House Institute of the United States are stringent and while ERVs and HRVs are not required for Passive House certification, in most climates, they’re necessary to meet PHIUS criteria for annual heating demand/peak heating load, according to Lisa White, a Certification Manager at PHIUS. “It is difficult to achieve such low heating loads without heat recovery ventilation,” she says.
There are three values used to determine a home’s maximum design airflow rate. “For passive house residences with typical occupancy, we design for continuous ventilation of 0.3 air changes per hour (ACH),” she says.
- Required supply air per person – We design for 18cfm continuous of supply air per occupant
- Volumetric requirement of 0.3 ACH – based off of your ventilation volume
- Exhaust air requirements – Typical design settings for continuous ventilation in exhaust rooms is 12cfm for half bath or laundry room, 24cfm for full bath, and 36 cfm for kitchens.
The NAHB Green Building Guidelines recognize IAQ as a primary aspect of green building. Mechanical ventilation is one of the major point-getters when meeting the standards: if the home provides mechanical ventilation to the tune of 7.5 cfm per occupant, as well as kitchen and bathroom ventilation, seven points will be awarded. Homes that use an HRV or ERV earn 10 points in addition to the above ventilation points.
LEED offers one point for indoor air quality. The credit calls for exceeding the minimum outside air requirements set by ASHREA by 30 percent. Increased ventilation helps reduce concentrations of carbon dioxide produced by occupants, and pollutants produced by off-gassing of construction materials and furnishings, but the extra ventilation required may also increase energy consumption in the home.
Ventilating for allergy sufferers
For the 25 million Americans with allergies or asthma, ventilation plays a key role in everyday life and IAQ in homes is a major problem. “Allergens and irritants are present in every stage of a home-build, the move-in, and remodeling,” says Mike Tringale, the senior vice president of the Asthma and Allergy Foundation of America.
Tringale says there are many things builders can do and materials they can choose that are less problematic for asthma and allergy patients, such as low-VOC paint, gypsum that is mold resistant and wood products that are treated with less preservatives, but ventilation is still key in controlling what allergens and irritants get into the house. The type of ventilation system doesn’t matter as much as making sure the system is properly installed. “Some HVAC systems are better than others, but it’s all about the ducts or conduits.”
Installers should make sure the ducts are sealed completely and that joints are perfectly fitted, and that the system is properly installed so that ducts for each room are filtered properly.
The right amount of ventilation and filtration are keys to creating and maintaining good IAQ.