HVAC Filter Placement

[Agee]

Any experienced HVAC folks?

The air handler for my home is installed in the crawl space. The filter is a reusable type which is inline just before the air handler. Being in the crawl space it is a pain to remove, clean and replace. The return in the house is large enough for a full size filter, but there is no filter frame. If I install a filter frame and filter inside, would I need to remove the filter in the crawl space? Would having both inline affect the air flow?

Thanks for any advise!

 

[PeoplesElbow]

Any experienced HVAC folks?

Would having both inline affect the air flow?

Thanks for any advise!

Anything you do including bends, joints etc will have an effect on the air flow, it is only a question of how much.

I would imagine filters can be placed anywhere on the inlet side.

While the higher MERV filters do filter better the lower number ones allow better airflow, I think I read somewhere that for household use a MERV is really the highest you would need, the higher ones are because people always think bigger is better.

 

[struggler44]

Install a filter grill where your present return grill is and remove the filter in your crawl, you don't want 2 filters in the system..... on a side note, you will be cutting your drywall about an inch to get the new filter grill in.

 

[Agee]

Thank-You both!

 

[General Lee]

I have 2 filters on my system. Bottom line is you cannot have to much air to the system. Most cases the more the better. Mine didn't always have 2, the second was added right the unit at the fan to provide more air as the unit wasn't getting enough. Upstairs return was to small. I would just use the cheap 30 day filters and change them regularly and they provide more air. I've dealt with many HVAC companies and none recommend those thick expensive pollutant catching ones.