Remodeling for Air Quality: March 2008 Archives
Researchers in England found that building a new home emitted four and-a-half times as much carbon dioxide as refurbishing an existing dwelling.They also found that the carbon dioxide emitted as a result of the construction of a new building - from quarrying, brick making and so on - accounted for nearly three times more of a building's lifetime emissions than had been supposed.
Previously the amount of energy involved in the construction of a home had been assumed to represent 10 per cent of the energy used over the lifetime of a building.
In fact, energy involved in construction added up to nearly 30 per cent of the emissions over the lifetime of the building, according to the report "New Tricks with Old Bricks; how reusing old buildings can cut carbon emissions." Telegraph, UK
So you can feel better about remodeling an old building than about building a new one. Another benefit of remodeling old structures is reduction in urban sprawl. When new wilderness or agricultural lands are transformed into suburban housing, we lose many additional benfits of nature's natural systems: plants (especially native plants) provide air filtration, water capture and replenishment of aquafers and water tables, wildlife habitat, cooling of the earth, and natural processing of waste -- from animal carbon dioxide to poop :-) Nature works hard for us and we can return the favor by reusing what we have already taken out of the natural system instead of adding to the concrete jungle.
There are many types of mold, and none of them will grow without water or moisture.
Molds are usually not a problem indoors, unless mold spores land on a wet or damp spot and begin growing. Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins).
Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes, and skin rash (dermatitis). Allergic reactions to mold are common. They can be immediate or delayed. Molds can also cause asthma attacks in people with asthma who are allergic to mold.
Indoor mold growth can and should be prevented or controlled by controlling moisture indoors. If there is mold growth in your home, you must clean up the mold and fix the water problem. If you clean up the mold, but don't fix the water problem, then, most likely, the mold problem will come back. By fixing water leaks, you not only control mold -- but can reduce your water usage and water bill -- as well as future mold removal costs.
Guide to Mold, Moisture and Your Home by EPA's Office of Air and Radiation Indoor Environments Division.
Quality of the air and environment inside buildings is based on pollutant concentrations and conditions that can affect the health, comfort and performance of occupants -- including temperature, relative humidity, light, sound and other factors. Good IEQ is an essential component of any building, especially a green building.
Creating a better indoor environment can help building owners, managers, occupants, architects and builders to minimize or eliminate the negative health effects, liability, bad publicity, and costly renovations and repairs often associated with IEQ problems.
Improving IEQ involves designing, constructing, commissioning, operating, and maintaining buildings in ways that reduce pollution sources and remove indoor pollutants while ensuring that fresh air is continually supplied and properly circulated.
EPA’s Indoor Environments program promotes the use of integrated, whole building approaches to protect occupant health while saving energy and money. The program focuses on major building types including offices and institutional buildings, schools, homes, as well as major cross-cutting indoor air quality issues like mold and moisture. EPA offers resources from informational pamphlets to interactive CD-ROMs on how everyone from builders to homeowners can improve their indoor environment.
Call EPA's Indoor Air Quality (IAQ) Information Clearinghouse at 1-800-438-4318. Or visit EPA's list of free publications at epa.gov/iaq/pubs
Pleated or extended surface filters Medium efficiency filters with a MERV of 5 to 13 are reasonably efficient at removing small to large airborne particles.
Filters with a MERV between 7 and 13 are likely to be nearly as effective as true HEPA filters at controlling most airborne indoor particles. Medium efficiency air filters are generally less expensive than HEPA filters, and allow quieter HVAC fan operation and higher airflow rates than HEPA filters since they have less airflow resistance.
Higher efficiency filters with a MERV of 14 to 16, sometimes misidentified as HEPA filters, are similar in appearance to true HEPA filters, which have MERV values of 17 to 20. True HEPA filters are normally not installed in residential HVAC systems; installation of a HEPA filter in an existing HVAC system would probably require professional modification of the system.
RESOURCE: EPA Guide to Air Cleaners in the Home
Some air cleaners use ultraviolet (UV) light technology intended to
destroy pollutants in indoor air. These air cleaners are called
ultraviolet germicidal irradiation (UVGI) cleaners and photocatalytic
oxidation (PCO) cleaners. Ozone generators that are sold as air
cleaners intentionally produce ozone gas, a lung irritant, to destroy
pollutants.
- UVGI cleaners use ultraviolet
radiation from UV lamps that may destroy biological pollutants such as
viruses, bacteria, allergens, and molds that are airborne or growing on
HVAC surfaces (e.g., found on cooling coils, drain pans, or ductwork).
If used, they should be applied with, but not as a replacement for,
filtration systems.
- PCO cleaners use a UV lamp along
with a substance, called a catalyst, that reacts with the light. They
are intended to destroy gaseous pollutants by converting them into
harmless products, but are not designed to remove particulate
pollutants.
- Ozone generators use UV light
or an electrical discharge to intentionally produce ozone. Ozone is a
lung irritant that can cause adverse health effects. At concentrations
that do not exceed public health standards, ozone has little effect in
removing most indoor air contaminants. Thus, ozone generators are not
always safe and effective in controlling indoor air pollutants.
Consumers should instead use methods proven to be both safe and effective to reduce pollutant concentrations, which include eliminating or controlling pollutant sources and increasing outdoor air ventilation.
Visit www.epa.gov/iaq/pubs/ozonegen.html for more information on ozone generators sold as air cleaners.
Usually the best way to address this risk is to control or eliminate the sources of pollutants, and to ventilate a home with clean outdoor air. The ventilation method may, however, be limited by weather conditions or undesirable levels of contaminants contained in outdoor air. If these measures are insufficient, an air cleaning device may be useful.
Some air cleaning devices are designed to be installed in the ductwork of a building’s central heating, ventilating, and air-conditioning (HVAC) system to clean the air in the whole house.
Portable room air cleaners can be used to clean the air in a single room or specific areas, but they are not intended for whole-house filtration.
Pollutants that can affect air quality in a home fall into the following categories:
- Particulate matter includes dust, smoke, pollen, animal dander, tobacco smoke, particles generated from combustion appliances such as cooking stoves, and particles associated with tiny organisms such as dust mites, molds, bacteria, and viruses.
- Gaseous pollutants come from combustion processes. Sources include gas cooking stoves, vehicle exhaust, and tobacco smoke. They also come from building materials, furnishings, and the use of products such as adhesives, paints, varnishes, cleaning products, and pesticides.
RESOURCE: EPA's Guide to Air Cleaners in the Home This document describes performance characteristics associated with several types of air cleaners sold to consumers for home use. It does not discuss the effectiveness of air cleaners installed in the HVAC systems of large buildings, such as apartments, offices, schools, or public buildings.
