Improving Indoor Air Quality Can Boost Your Family’s Health and ComfortPublished on: November 29, 2013
According to the U.S. Environmental Protection Agency, Americans on average spend a staggering 90 percent of their time indoors. And because indoor air, cut off from the air circulation patterns of the outside environment, usually contains two to five times the amount of airborne pollutants as outside air does, all that time spent inside can quickly begin to present health and comfort challenges. Improving indoor air quality is an important task for any homeowner and, in this article, we’ll help you understand how air quality affects you, how it’s managed and strategies for improving indoor air quality in your southeastern U.S. home.
Why Do Pollutants Concentrate Indoors?
The Earth has its own air purifiers in the form of plants, especially in wetlands areas common in the southeastern United States. Wind also helps to disperse pollutants, reducing their concentrations. However, when a home is constructed, the walls and ceilings dramatically reduce the degree of air exchange with the outside world; and for home comfort, this is a good thing. Sealing your home prevents uncomfortable drafts, heat gain in summer, and heat loss in winter, not to mention any local problems like pollen during the allergy season.
But because a sealed, energy-efficient home is cut off from the larger natural air purification systems, new systems must be intentionally installed to provide those services. This is the reason, for example, that your furnace and air conditioners come with air filters, and why your stove may have a mechanical ventilation system such as a hood and/or fan.
Many pollutants can also originate inside your home, and need to be dealt with, such as smoke and fumes from cooking, fumes from cleaning supplies and pet dander.
Why Is Indoor Air Quality Important?
Improving indoor air quality isn’t just a cosmetic difference in your home environment, it can have tangible health effects, and significantly increase your home comfort.
Air pollutants can include particles such as mold spores, bacteria and pollen which can trigger or aggravate allergic responses – or they may be even more dangerous, such as asbestos fibers in older homes, or the deadly carbon monoxide gas – a colorless, odorless substance which is the natural by-product of certain heating installations, which can cause flu-like symptoms, unconsciousness and even death when present at elevated levels. (All homes should install one or more carbon monoxide detectors to alert residents if CO levels rise beyond their safe baseline amounts.)
Beyond the specific ailments which may be caused by airborne bacteria, such as Legionnaire’s disease, residents in buildings with poor air quality can experience headaches, eye irritation, itchy throats, dizziness and fatigue from spending too much time breathing polluted indoor air. On a more comfort-oriented note, indoor odors will also tend to linger in homes without proper circulation, ventilation and air purification.
How Can You Approach Improving Indoor Air Quality?
There are several strategies for improving indoor air quality, not all of which may be appropriate for your particular home needs. Knowing what functions each of these serves is the first step in establishing an air quality strategy for your home.
Built-in Air Filters
Forced-air furnaces and air conditioners come with air filters installed – frames with a fibrous mesh which air is forced through as it leaves your HVAC system to circulate through your home. As air is pushed through the filter, particulates are caught on the mesh and removed from your indoor air. (Because, over time, these particles will clog up the filters and impede airflow, filters should be replaced every month or every other month.)
Filters used in home HVAC systems vary in their effectiveness, which is measured by a rating called MERV: the Minimum Efficiency Reporting Value. MERV ratings used on home air filters fall in the 1-16 range, with higher numbers representing more power to clean your air. In a nutshell, these values represent:
- 1-4: The most basic filtration. This will catch large particles such as dust mites, sanding dust, carpet fibers and pollen.
- 5-8: Mold spores, pet dander, aerosols such as hair spray and fabric protector, and particles as small as pudding mix will be caught by filters in this range.
- 9-12: Large bacteria (such as Legionella) and particles as small as flour are filtered out in this MERV range.
- 13-16: Offering superior protection, these filters will catch most bacteria, smoke particles and particles as small as face powder.
Built-in air filters are a good first line of defense against airborne pollutants, but their capacity for improving indoor air quality is dependent on how well air circulates through your HVAC system, and they alone may not be enough to meet your air quality goals.
Stand-alone air purifiers
Stand-alone air purifier units can be placed in problem spots in your home, such as a workshop or kitchen, for a significant, if localized, air quality boost. These units don’t rely on a running HVAC system (so they can provide continual coverage during clement weather), and are more efficient at removing airborne pollutants than a simple furnace or A/C filter.
Stand-alone units have their own fan to circulate air, and their effectiveness is measured by the CADR standard: the Clean Air Delivery Rate. This rate, expressed in cubic feet per minute, compares the air cleaner’s performance to what would be achieved by adding that many cubic feet of clean air to your home per minute.
While these air cleaners can give a boost to certain living areas, and may be a good choice for certain areas with elevated purification needs, they don’t have the circulating capacity to purify air throughout your entire home.
Whole-house Air Purifiers
These installations are placed in a central part of your HVAC system, or may be installed within the ductwork itself, and deliver exceptional additional filtration to air circulating throughout your entire home. For homes with elderly or very young residents, or those with vulnerable immune systems, a whole-house air purification system with HEPA filtration might be a good investment – HEPA, or High-Efficiency Particulate Air filtration, is a standard in hospitals and manufacturing clean rooms, and can filter out viruses, smoke and other microscopic particulates.
HEPA filtration exceeds the needs of most residences, but is always an option for homes which require the highest grade of air filtration. These filters are seldom, if ever, installed as traditional HVAC air filters because their high air resistance would negatively impact the system’s performance.
Parts of your HVAC system, such as the evaporator coil inside your air conditioner, can be prone to high humidity and thus mold and bacteria growth. UV lights installed within your HVAC system can sterilize coils, filters and ductwork, improving indoor air quality by preventing the growth of harmful microorganisms and improving HVAC system efficiency by preventing organic buildup which can clog filters and vents.
Purifying your air inside your home is one strategy, but adequate ventilation should also be maintained in your home. Removing pollutants such as kitchen fumes and removing high-humidity air in kitchens, bathrooms and utility rooms with washers and dryers, is a task for ventilation systems.
In order to prevent heat loss in winter and heat gain in summer, you may want to look into a heat recovery ventilator. This HVAC system upgrade transfers heat between incoming and outgoing air, maintaining your home’s temperature while still bringing in fresh air from the outside world.
Take action today!
As the heating season approaches and homes will be increasingly closed up against the chilly weather outside, improving indoor air quality becomes increasingly important. To learn more about the strategies outlined above, or to schedule assessment or installation for any of these options, visit our site at AC Southeast, we can put you in contact with qualified contractors throughout the southeast U.S. to help you meet your home comfort goals.