Which one to choose? Does a furnace needs a filter at all? For a subject as simple as furnace this, it is surrounded by too many misconceptions.
To get rid of them, let's start from a few basic facts.
First of all, a furnace does need the filter.
As a matter of fact, the main reason for the filter being there is to protect the furnace.
We can try to accomplish more things, like -- remove allergens, bacteria, etc.
- but the first and the main thing is the furnace protection.
The trouble is the filter not only protects, it may just as well harm the furnace.
Let it happen and you will pay dearly.
The entire air flow has to pass through the furnace filter to enter the furnace.
The filter placed into the air stream creates resistance to the air flow and reduces it.
Too dense, or dirty for that matter, a filter may choke the air flow almost completely.
Some of the signs of severe air flow blockage are: - The furnace is overheating.
It will go through frequent repairs and fail prematurely.
- The air conditioner is freezing.
At the very least you will loose cooling and have to pay for a service call just to replace the furnace filter.
- Remote rooms in the house do not get enough air.
They are cold in the winter and hot in the summer.
To choose the right filter start from how you use the fan in your furnace.
If furnace fan is not running continuously, in automatic mode it operates approximately only 20% of the time.
In this case, the furnace filter won't do much for the dust collection in the house no matter what filter model you choose.
A regular furnace filter will do just fine for you since you need the filter only for the furnace protection.
More dense filters will only reduce air circulation without doing any good in exchange.
The verdict - do not even bother spending money on expensive options.