First of all last week I dreamed I was in an HVAC class at a local Tech. School. Woke up in a cold sweat, an old man, trying to install HVAC equipment. Oh my aching back.

The real reason I am posting:

Really confused about the kind of filter to use on the air handler for a heat pump. Some of you pros. say to use a standard one inch blue filter to just protect the equipment. I have been using the 3M filterete brand and change every three months.

Never used or intend to use an electrostatic filter based on what you all have said.

Is there a correct answer?