Welcome to Bragg Heating's Customer Information Page. Every month we will offer a new column with useful information on all aspects of a heating and air system.
March 2009 - Filtration
This month's column deals with proper filtration for your system. This is the one area that you the customer are directly responsible for the health of your system. There are several ways to filter the air entering your system. Filter effectiveness is measured by MERV(Minimum Efficiency Reporting Value). Your filter will have a MERV number between 1-16. The higher the number, the better your filter removes debris. Listed below are several filter options:
- Standard throw away filters
- Pleated filter
- Electrostatic filters
- Media air filters
- Electronic air filters
Let's take each of these options and discuss the advantages and disadvantages of each.
1) Standard Throw Away Filters
This is the cheapest option available, normally costing around $1-$2 per filter. These filters normally have a MERV of between 1-4. On average they only catch the largest particles that go through them. The particles that get through will start to form a coating on either your heat exchanger or your cooling coil. If it catches on your heat exchanger, it will produce a burning smell every season when you cut on your heat. This is because your heat exchanger is burning this layer of debris off. If it catches on your cooling coil, it slowly forms a layer of dirt on your cooling coil. As this layer grows on your coil, the cooling capacity, as well as efficiency is reduced. It is not uncommon for a system to lose 25% of it's efficiency within 3 years due to debris build up. If you are using these types of filters, you should check them once a month.
2) Pleated Filters
These are much improved over your standard filters. Their MERV rating is around 8. They normally cost between $5-$10 per filter. They are designed like a small accordion, with a filter area that goes in and out. This actually enlarges the filter area itself. These filter also have a thicker weave and catch more of the particles that go through them. They do need to be replaced every one to two months.
3) Electrostatic filters
These are 1” thick filters with three to four layers(either plastic, foam, or polyesters) woven in an interlocking pattern. These layers form an electric charge which causes dust to cling to them. There are many different types, with MERV ratings anywhere from a 4 up to a 10. So check out all the technical information before you purchase these. Most filters can either be washed or vacuumed. Also, most are warranted for 10 years. Some even have a lifetime warranty to the original owner. These filters can cost from $50-$125. One thing to keep in mind, as these filters collect dust and debris, they will cause your system to work a little harder to move air. So you want to make sure you clean these filters every month.
4) Media Air Filters
These are 3”-5” thick media filters that are normally located in a metal cabinet in your return ductwork near the furnace or air handler. These filters have a MERV of 10. There basic design is like the pleated filters, except they are much bigger. Depending on your system use, they should be changed once to twice a year. Average cost to replace a filter is $35-$40. This filter is really good at normal dust and debris in your house.
5) Electronic Air Cleaner
These are the air cleaners you need if you have health issues(especially breathing problems). Most have MERV ratings of 14-16. Some like the Trane Clean Effects air cleaner are higher than that. These air cleaners catch and remove the smallest particles, even down to .03 microns. On average, they remove between 98%- 99.98% of the particles that go through them. Average cost for these are anywhere from $800-$1500 depending on the manufacturer and installing company. They do need to be cleaned at least once a year to maintain their efficiency.
Options 4 and 5 will require a Heating contractor to make the necessary duct transitions to connect your air cleaner to the return duct system.
Hopefully this information has been helpful.
If you have any further questions, please feel free to call us at 648-0387.
You may also contact us with any questions or concerns.
Finally, if you have a question that you would liked answered,
e-mail it to us and we will answer it in a future column.