How to choose the right filter for your HVAC system
How do you choose an air filter? It can be so confusing.
Well, first of all, you should measure the opening of your uptake vent. Once you know the correct size, it's important to price them. You can buy filters just about anywhere, unless you have an odd size. Walmart, Lowes, Home Depot, even some grocery stores keep them in stock. You can also find them online. A site like filtersonline.com is a good placr to check especially if the filter you need is an odd size or you want to buy a case at a time.
If you are changing your filters as regularly as you should (depending on the level of use you are giving your unit), you may want to buy a carton of filters. Buying 6-12 filters at a time can often bring you substantial savings.
But back to the question: how do you choose which kind of filter to buy?
We're going to talk about two specific things to consider: the material and how it's used in the product and the MERV scale rating. MERV stands for the Minimum Efficiency Reporting Values. It goes from 1-20, 1 being the least effective and 20 being the most effective at filtering.
Here is a quick summary of the most commonly available types of filters, starting with the least expensive:
1. Disposables: these filters are the least expensive. There are flat, fiberglass ones that don't really clean the air of allergies but will help to keep your furnance from getting too yucked up with dust. Their MERV rating is about 3-6.
Then, there are pleated ones made from cotton and polyester that clean alittle better but must be changed frequently or they will bog down the HVAC. Their MERV rating is usually 6-8.
Lastly, in the disposables, there are electrostatic filters that have paper fibers that will trap smaller particles. These are certainly the best of the disposables. MERV here is about 10.
2. Permanent: these filters last 5-10 years depending on how much use your system gets. Permanent electrostatic filters have a removable, washable filter. This could be considered a greener option because you're not throwing away a filter every 3-6 months. MERV rating is 8-10.
The last type of filter is the high-efficiency pleated filter which is commonly used in hospital settings. These are expensive and are installed with a special HVAC system. They can be used in a home setting, but the expense is a deterent for most people. Their MERV rating is 14-16.
Here are some additional questions you can ask yourself in order to determing what sort of filter you should buy:
Are you are a renter, or do you own your own home?
Do you smoke? Have animals inside?
Do you have asthma or allergies?
Do you have elderly people, or people with compromised immune systems living in the home?
You also want to think about extending the life of your HVAC system by changing your filters or washing your filters regularly: every 30-60 days with heavy air con use in the summer and heavy furnace use in the winter. Every three months most other times.
Also, you will want to see that your HVAC system gets regular maintenance. Your HVAC professional can also help you determing which HVAC system and filters are best for your home.