Indoor Air Quality
Inside our homes and businesses, in which we spend the majority of our time, we are subjected to a variety of airborne contaminates. Thank goodness for our immune system that protects us from many potential problems, but this amazing system can be overwhelmed or become immune if constant levels of pollutants are maintained. There are a number of solutions that address IAQ problems, and many times more than one solution is required.
Cleansing the air through a filter is usually the first step in reducing airborne contaminates. If the home or business has a duct system, then there are many products available. The first thing to remember is the standard 1’’ furnace filter is designed to protect the piece of equipment from dirt and dust build-up that could be unsafe and reduce efficiency. These filters usually do not provide much improvement in IAQ unless they are a pleated variety and changed often. Deep pleated filters are much more effective and come in a variety of sizes and efficiencies. They have a much longer service life (usually a year), and have less airflow restriction than a 1’’ filter. Some duct modifications are usually necessary to adapt these filter cabinets to your existing duct system.
Beware of a few pitfalls in filters, mainly airflow restriction. The “Electro-Static” models are plastic weaved between frames and are promoted to have better efficiency and washable. My many years of experience with these filters are they cause more problems than they solve. They quickly “load-up” and reduce airflow to dangerous levels causing overheating of equipment and potential damage to the machine. Any filter you can see through is to be avoided; this is more of a screen than a filter. Please remember any good filtration system can set you back hundreds of dollars and maintaining the filters requires an investment in your health.
The last word in filtration is “HEPA”. It stands for high efficiency particulate air. This is an overused term and associated with deceptive advertising that is over the top. HEPA this, HEPA that, everything is HEPA grade and this is simply not true. A true HEPA filter is extremely dense and very restrictive to airflow. There are no true HEPA filters to fit in your 1’’ filter slot on your furnace, despite what the label says. Lennox makes a true HEPA filter system, but it is in a separate cabinet with its own blower to overcome the massive pressure drop. Look for “MERV” ratings instead. This stands for minimum efficiency reporting value, and most good filters are 10-16 MERV rated.
Putting light bulbs in your ducting sounds a little funny but it serious stuff at every hospital. Operating rooms and surgical centers use an abundance of UV light to purify the moving air. They certainly use excellent filtration, but purification is just as important to minimize airborne viruses and bacteria. Residential UV systems are relitivly inexpensive, easy to install, and very effective. Most require bulb replacement annually to ensure proper performance. Please note that some plastics in A/C coils and filter racks can be affected by UV exposure.
Adding humidity to a home or business is a fairly standard task and can be accomplished in a number of ways. Because it is fairly dry here, many homes do drop indoor humidity levels to uncomfortable and unhealthy levels. 35% relative humidity is the standard target. Analyzing the home and deciding if adding humidity is the correct course of action is very important. I have had many folks that want a humidifier, but by using an accurate hygrometer, many times installing a humidifier is unwarranted. With a higher performance home that is built properly, air infiltration is limited and therefore humidity tends to build-up in the home. Adding humidity will be counterproductive to this type of home. The investment in the humidifier will either be unused or by adding humidity windows may begin to sweat and mold and mildew could become a real problem.
If installation of a humidifier is decided upon, then you need to figure out which one. All humidifiers are rated in gallons per day of evaporation. Most all models rely on the warmth of the furnace supply air to evaporate the water. This is very effective when the furnace is running, but as we approach the shoulder seasons where the furnace is running shorter cycles, evaporation is limited and becomes far less effective. This type of system does have its drawbacks but works pretty well in most cases.
For homes with lots of woodwork and wood furniture, a steam humidifier is the best bet to maintain the correct level of humidity. These models are quite a bit more of an investment and can exceed $1,000.00 installed. They will also need regular changing of filters and cleaning of electrodes. This can cost a couple hundred dollars annually as well. Steam humidifiers will also consume quite a bit of electricity. This is not to be taken lightly as will add up. As much as these issues make a steam humidifier seem undesirable, these units do perform in all situations. Many homes have very expensive furniture and a good humidifier is an investment in maintaining these heirlooms.
There are several thermostat manufacturers that have implemented the standard temperature controls with indoor air quality components. It is very convienient to have one display in the hallway that allows you to monitor filtration, ventilation, humidity, and, of course temperature. Not so long ago there were numerous components mounted on and around the furnace. Adjust this, turn that, check this thing. Now the thermostat sets maintenance schedules, and monitors operation of the system right from the hallway.
A further enhancement is the addition of internet connectivity to many of these thermostats. You can simply log on and check environmental conditions at the home, especially convienient if you travel or go south for the winter. These controls will also contact you if a problem is detected or temperature parameter of offsetting. Investing in a good control is very important to get the most from your HVAC system.
Ventilation is something we assume is happening in our homes and business. We all need fresh air and it becomes quite apparent when you walk in a building and it has the aroma of sweaty socks that maybe somebody should open a window. We are building homes tighter and tighter to increase efficiency, this just seals in more contaminates that otherwise would be whisked away outside. Specifying a ventilation system in a new or existing home is often times just thought of as a frill that can be cut from the budget. Many times I have visited very nice, well built homes that bottle up every volatile organic compound that it took to build the home. It smells better than sweaty feet but, it is absolutely not a cocktail that you want to breathe.