There are a few questions that must be addressed before you can set up a schedule to change your air filter.
· Do you buy an economy filter or more expensive MERV (Minimum Efficiency Reporting Value) filter?
· How thick is the filter for your system, 1” or thicker?
· How many people occupy your home?
· How many pets do you have?
· Environmental issues in your area: Dirt back yard, construction, urban etc?
· Your personal health needs?
· Vacation home or full-time occupancy?
Once you know some of the factors that can impact the life of your filter, it is easier to identify a schedule for replacement.
An economy filter with an average size home and family may need to be replace every two months, but when you add a pet or two, that time can be impacted, and you may need to change it monthly.
A home full of people may also require a monthly schedule for replacement, even if you have a more expensive filter.
If you live in an area with long term construction, those air borne particulates will eventually find their way into your home, requiring a more aggressive change out schedule. As well, living in an urban area, near farming or especially if you have a dirt yard at your home, will also require more often changes.
One of the most important factors however is your health requirements. If you have respiratory issues that require inhaled medications or home oxygen, you will want to purchase a thicker more expensive filter and change more frequently, even if you have no pets.
Ultimately, when the filter starts to turn gray, or there is a buildup of material in certain locations on the face of the filter, it is time to replace it.
When shopping for an air filter for your home, the first thing to recognize is that there is no difference between the A/C filter and the furnace filter. Your home system pushes air through the house, using the same filter regardless of whether you are using heat or air conditioning.
The air filter in most homes sits between the return air duct and the A/C system, or in a “return air duct” either in the ceiling or close to the floor. The location depends on the type of A/C system you have. Some homes have one large unit on the roof called a “package unit” where other homes have one part outside, the “condenser” and the other half inside called the “air handler” or “furnace”. Always install a new filter with the small “arrow” pointed in the correct direction, pointing towards the air conditioning system.
Next thing to identify is the correct size. If you just moved into the house and there is an existing system, turn off the system, open the vent and remove the filter. Look at the edge of the filter, and there is more than likely printing, which will tell you the size you need. If there is nothing printed, you can use a tape measure to get the length, width and thickness. Once you find the size you need, you may want to take a permanent marker and write it on the side of the air handler/furnace or the inside of the vent cover for future reference. It is very important to buy the correct thickness, as this is part of the design and specification of your specific system.
So now the big question, what MERV rating do I get? MERV stands for ‘Minimum Efficiency Reporting Value.’ What this really translates to is how small and how many particulates this filter will stop. The lower the MERV rating, the worse it is, so a MERV rating of 1 is the worst rating and 16 is the highest. When you go shopping for your filter, don’t just go get the highest MERV filter you can find. Higher MERV translates to lower air flow through your system. If your system needs a specific amount of air flow, and you restrict that, you can actually cause some problems that will impact your cooling or heating for your house. Contact an HVAC professional to look over your system is you have questions. On the other end of the spectrum, don’t buy the cheapest, lowest MERV filter, as it will not stop most particulates and will need top be replaced much more often. These lower price filters can also cause serious issues, by allowing too much crud through, causing the inside Evaporator coil to get clogged up. This will reduce the air flow through the house, raise electric costs and even freeze up your outside condenser coil.
Testing filters can give you a good idea of which filter works best with your system.
The type of A/C system you have can be initially broken into two main types; package and split. From there, you can further break down the exact type of system by gas, electric, straight A/C, heat pump and so on.
To figure out the first and easiest type is to go outside look to see where your system is. Most systems that sit on your roof are called package units. A package unit has everything the system needs, in one convenient ‘package’. That means the condensing coil, evaporative coil and blower motor are all housed in the same big box.
The next is a split system. Most of these in residential homes, are broken into two main parts; the condenser which sits outside (usually on the ground but can be found on the roof) and the evaporative coil, which is found somewhere in the house, (many times in a closet designed specifically for this unit).
Both package and split have a motor, that blows air throughout the house. This motor is found on the evaporator side of the system.
Knowing which system you have is important to know, as air filter placement is impacted by which you own. Split systems will usually have the filter in the closet with the evaporative coil, and the package unit will have a filter in a return air duct opening, which can be found in the ceiling of some homes or near the floor in others.
Straight cool refers to a system that only produces cold air only, relying on a gas or electric furnace to produce heat. A heat pump actually produces both cold and warm air, depending on your thermostat setting. When you have a heat pump system, you may also have electric heat strips to help produce hot air immediately. Those heat strips are usually located in the air handler near the evaporative coil.
If you have any questions regarding your system or efficiency rating and electric use, please feel free to contact your HVAC professional.
Like many appliances, we tend to forget about our A/C system when it is working as we expect it to. Unfortunately, we only call for an inspection when the system starts to fail or fails completely. In most instances, an annual inspection will forestall major complications for a significant amount of time.
An annual inspection will keep coils clean. This keeps the system running efficiently, which keeps electric bills as low as possible. Over time, buildup on the coils cause restrictions. These restrictions cause you to keep the system on longer and force the system to work harder to keep your house at the same temp it used to be able to hit easily.
An annual inspection will also allow your technician to spot a small problem before they become a major one.
During your inspection, make sure to ask your Technician if there are any new technologies that may help with efficiency, IAQ (Indoor Air Quality) or specials that may allow you to upgrade your entire system.
If you currently have a home that uses an evaporative cooler, you are in luck. There are some benefits to using a cooler during certain periods of the year, and you can even add an A/C system to work in coordination with your current cooler. Or you can replace the evaporative cooler entirely. It is completely up to you and what makes sense in your home.
Benefits to an evaporative cooler include:
-Lower initial cost to install
-Lower electric bills when in use compared to a comparable CFM A/C system
-Works great in low humidity climate
Benefits of an A/C system include:
-More precise control of temperature, including heat during the winter
-Cleans the air circulating in the home
-No need to winterize the system
-Increase value of home when it goes on the market
-No need to keep windows or doors open
HVAC – Heating, Ventilation and Air Conditioning
SEER – Seasonal Energy Efficiency Ratio: SEER measures the air conditioners cooling efficiency by calculating the annual cooling output for a typical season divided by the total electric energy input during the same time frame. The SEER is the maximum efficiency rating, but much like MPG for a car, some conditions will impact that rating. Driving on the freeway gives you better gas mileage than driving in the city.
BTU – British Thermal Unit: The energy required to raise one pound of water, one-degree Fahrenheit.
HSPF – Heating Seasonal Performance Factor: The measure of heat efficiency of the period of a heating season.
TXV – Thermostatic Expansion Valve: A piece of equipment that meters the flow of liquid refrigerant into the evaporator while measuring the vapor refrigerant leaving the evaporator.
AFUE – Annual Fuel Efficiency Ratio: A thermal efficiency measure of gas furnaces. A gas furnace with an 80% AFUE produces 80 BTU of useful heating for every 100 BTU’s of natural gas input. The 20% loss in this example is lost in the exhaust. The higher the AFUE, the more efficient the system is.
HEPA – High Efficiency Particulate Arresting: A type of air filter used to remove 99.97% of the particulates that are greater than or equal to 0.3 µm (micrometer) in size.
IAQ – Indoor Air Quality: A term used to describe the air quality in and immediately around a building or structure, as it relates to the health and comfort of the occupants of the building or structure.
NATE – North American Technician Excellence: The nations largest non-profit certification program for heating, ventilation, air conditioning and refrigerant technicians.