Indoor air quality is nothing to sneeze at anymore ... okay, bad pun, but our industry is finally starting to realize the role it plays in the overall comfort and "live-ability" of your home. We are realizing that we can do a better job at removing dust, dirt, mold, mildew, microbes and other impurities in the air.

The key to any IAQ program is maintenance. Regular filter changes or cleaning are important. Duct inspections are important, too - ductwork that is leaking or improperly sealed can pull unfiltered outdoor air into your home. One of the biggest problems with air conditioning systems is standing water in the evaporator's drain system. Your air conditioner's evaporator system is a perfect breeding ground for mold, mildew, and other nasties that can affect your health. Only through regular maintenance can you be sure that your drain systems are operating properly. Call us today to schedule your IAQ checkup.

The heart of any IAQ program is your filtration system. Several types of filtration systems are available to consumers other than the standard fiberglass throwaway filters:

Electronic Air Cleaners

EAC devices use some form of electronic "grid" to trap and eliminate dust, dirt, and other particulate matter. Often this is in the form a cross pattern of charged wires known as a "grid". EACs can trap eliminate particles as small as 1 micron, but do little to eliminate odors or non-airborne matter. EACs are installed in your home's duct system just before the furnace. EACs require annual maintenance (in some circumstances, this may be required more often), and this maintenance is not something the average homeowner can perform.

Electrostatic Filters

These filters are non-powered, and work by combining several layers of materials to form the filter. Most contain at least one layer of activated charcoal for odor control, and several layers of different materials to generate a small static charge when air is passed over them. This static charge is what attracts airborne particulate matter. These filters are washable and easy for the average homeowner to maintain

Media Filters

Media filters are relatively new to the HVAC world. They are basically large, thick pleated filters (4 - 5" thick), made from paper or some synthetic medium. These are somewhat dense, but since they have such a large surface area, they don't restrict airflow like some 1" air filters. These are non-powered filters, and are installed in your duct system (normally just before your furnace) and are changed generally once a year. The replacement media can be fairly expensive ($30 - $60)

Ultraviolet Lights

Filtration is important, but we've gone beyond that. We can now outfit you system with ultraviolet lights to kill microbes. These systems are effective in keeping down the presence of microbes, but only in the areas where the light is illuminating the area. Typically, you'd install a ultraviolet light near the evaporator coil, since this is where most microbes tend to collect. Note that UV lights do NOT keep ductwork clean, as some suggest; they simply kill microbes in the areas directly illuminated by them. UV lights must be handled very carefully and installed correctly; installation and maintenance is generally not something which can be performed by a homeowner.

Ventilation

One area often overlooked when dealing with IAQ is ventilation. New homes today are very tightly constructed, with tight fitting windows and doors, sealants - even "whole house blankets" that wrap the home in a layer of plastic. While this is great for energy efficiency, it doesn't allow the home to "breathe". Indoor air can become stale and polluted, and over time can become a health hazard. The answer: Whole House Ventilation. Ventilation can be as simple as opening a window or door, but often that's not the best solution when the temperatures get extreme. The solution? Let us install an Energy Recovery Ventilator in your home. An ERV allows us to tailor exactly how much air we bring into your home, and special construction of the ERV allows us to warm or cool the incoming air, which means you don't lose those dollars you spent heating or cooling!

Humidifiers and Dehumidifiers

Your home's air conditioning system doesn't just cool the air - it also removes humidity. When we talk of "latent" versus "sensible" heat, we're basically talking about the addition of humidity: Sensible heat is basically the temperature that we humans "sense", which is a combination of the actual ambient temperature correlated with the humidity level. If we can control the moisture content in our home, we can make our living space much more comfortable, and keep our air fresher and cleaner.

In our southern regions we have summer humidity, and lots of it. Often your home's a/c system just can't keep up with the demands (and in the Fall and Spring months, you don't want to run your air conditioner only for humidity control) and you end up with a house that's cool but clammy. That's not good for your comfort or for your indoor air quality. When humidity levels are too high - above 50% - mold and mildew flourish. There is no practical way to eliminate all mold and mildew from your home, but you can reduce the conditions which cause those spores to grow - and that means reducing the moisture level in your house. The answer is a whole house de-humidifier. These work by sensing your home's humidity levels and operating the furnace's blower system when conditions get our of range. These are installed next to your furnace, and are attached to your home's existing duct system. Some even come with optional fresh air intakes

While too much humidity can be a problem, in the winter months when our heating systems are operating we're often faced with the opposite - not enough humidity. Often our home's humidity levels can drop as low as 10% in the winter, and that's not good for people with breathing difficulties, and many experts agree that while mold and mildew don't like low humidity levels, viruses do. Dry noses, cracked, itchy skin, static shock, warped woodwork and moldings - all of these are signs that your home's humidity level is too low. What can you do? Install a whole-house humidifier. These systems install in your home's duct system, and operation in conjunction with your furnace and blower system. These systems sense the moisture level in your home and automatically add water vapor to your heating system. Most high quality systems use a "water panel", a porous surface that is saturated with water. Air from your furnace passes over these panels and pick up water vapor. Beware of the "atomizing" style of humidifiers. They do little more than spray a mist of water into your duct system, are prone to failure, and can cause severe water damage when they clog up.

As fuel prices rise, the need to more concisely control our home's heating and cooling has become more important. Older bimetal thermostats work okay, but they're prone to calibration errors and can have large temperature swings - neither of which are going to help you save on you home's energy use.

Enter the world of microelectronics. Today's digital thermostats use sophisticated technology to monitor the temperature in your home, providing you with more precise temperature controls. With a digital thermostat, the setting you choose is the setting you maintain - there is no more "dead band", and no more temperature swing. Digital thermostats are extremely accurate, and that results in lower power consumption for you.

There's another breed of digital thermostats as well - the programmables. A programmable thermostat allows you to control your home's temperature based on time periods. For example, in the summer you may wish to raise your home's temperature when everyone has left for the day, but have the temperature return to a comfortable setting by the time you get home. A programmable allows you to do this by storing "set points" and "periods". A "period" is simply a window of time - for example, 8:00 a.m. to 5:00 p.m. During that time, you may wish to raise your temperature up to 80 degrees. After all, if no one is home, there's little reason to keep the home in the normal human comfort zones.

Programmable thermostats come in different varieties. The top level units have touch screen settings, and can program dozens of periods for a particular day. Some of these can even interface with your home's computer system, allowing you to monitor and adjust your home's comfort level from any internet-connected computer.

Of course, not every system is a good candidate for a programmable thermostat. If you have a family member who is often at home - for example, if you work from your home - then a programmable wouldn't provide much in the way of energy savings. If you have an erratic schedule, or your schedule often changes, a programmable may not be the best choice.

The best way to determine if a programmable thermostat is the right one for you is to contact the pros at Wrenn for advice. We'll ask about your schedule, how you use your system, and recommend the right thermostat for your needs.