One of the most frustrating parts about using furnaces to heat your home is replacing furnace filters every month. The little fiberglass disposable filters can be a pain to navigate between models in the store, and are frustrating have to remember to take care of so regularly. However, in recent years permanent electrostatic filters have been developed to deal with a number of these issues. Unlike the cheap fiberglass counterparts, these filters are not disposable and last much, much longer.
Electrostatic furnace filters are a permanent filter that works by using a static electricity charge to attract dust particles. They are capable of capturing far more than a regular filter, even upwards of 94% of sub-micron dirt particles (compared to about 2% for your standard filter). Rather than being replaced, they need to be removed from the furnace and cleaned with water by a garden hose or shower every three months, then left out to air dry before being replaced. Even more interesting, electrostatic filters have little or no effect on the airflow through the furnace, meaning that they don’t lose efficiency over time like a fiberglass filter does.
However it is not all roses with these filters. Many furnaces need to be retrofitted to accept electrostatic and other green filters, and they cost a fair amount of money to buy. Yet since they need not be replaced every few months that price gap narrows over time, and they are significantly more effective and less hassle to use than their counterparts. This is why they are growing so popular to the average homeowner over the inconvenience of using disposable filters instead.