An HVAC filter is used to keep dust and debris out of the heat exchanger of a furnace and the air coil of an air conditioner. A filter helps to protect the equipment in use rather than purify the quality of air. However, more expensive filters can have a small effect on the quality of the indoor air if the fan is operating almost constantly. Like all HVAC filters, the expensive ones also get dirty and that affects the airflow since it will be restricted. This is why your filter needs to be cleaned or replaced on a regular basis.
A dirty filter can lead to a breakdown and/or reduce the life of a furnace. In addition, your energy costs will likely rise since the appliance will be working overtime to heat up or cool down your home. If the furnace’s heat exchanger becomes too hot due to restricted airflow, the unit’s heat sensor will automatically shut the appliance down. More expensive filters may restrict airflow more than cheaper filters due to the extra layers of filter media so it’s important to change them on time.
Most HVAC experts recommend that the filter be changed once a month during the peak winter and summer months such as January, February, July, and August. In general, these are the coldest and hottest months of the year in most areas.
During the rest of the year it’s a good idea to change the filter every two or three months. But the rule of thumb is to change it sooner if it’s dirty. If you suffer from allergies you may want to inspect the filter every two or three weeks since it’s possible for pollens to become stuck to the filter. These can then circulate throughout your home in the air. You may also want to inspect the filter more often if you have pets as pet hair can easily block the flow of air by clogging the filter.
The simplest and most effective way to check the condition of the filter is to take the time to inspect it visually. Less expensive filters are typically made of mesh and are non-pleated. If you can clearly see through the mesh then it’s not dirty, but if any area of the filter appears to be clogged or blocked it will restrict the airflow and should be changed. More expensive filters are pleated and it’s easy to see the dirt in them. If you haven’t checked the filter visually, but have noticed there is more dust in your home than usual then the filter could be dirty.
So when it comes to the cost of air filters, the more expensive ones may be worth the money if you suffer from allergies or asthma sufferer or have pets that shed. However, if you change the filter on a regular basis and your home is relatively clean and free of pet hair etc., then the less-expensive options are typically good enough to handle the job. Expensive filters, when dirty, can restrict airflow (due to thicker filters) and cause unnecessary strain on your HVAC unit..