Modification: return air grille and filter

[RuralPastor]

A recent post got me thinking. I have wanted to find a way to have quick/easy access to build a filter box for my furnace. Rather than removing the grille for the return air to change the filters (or have access to my pump), I added 2 hinges to the top of the existing grill and removed the four screws. I used a full-wrap style of hinge that is self-closing. When raised, the hinges hold the grille completely open. For a filter, my opening fits perfectly a standard 10 x 20 filter -- held in place with clips. I'll try to post a pic of the completed assembly later.

 

[ChopperBill]

Good idea. I stuck a filter in my cold air return but later found out while inspecting the basement it look like its a crap shoot where the air is coming from so I dont think a filter is going to help me out much.

 

[MC9]

I've had a filter behind the return air grill for a couple of years. If it catches a little dirt, it couldn't hurt. But, it cut a couple of DB's out of the sound.

 

[Bob&Patty]

I have "heard" that it's not a good idea to install a filter. I think it was on the forum. You might want to call HL service and ask about it. I could be wrong. I agree with Chopper, unless you can completely seal off the area around the heater plenum, you wasting your time. These heaters draw air from outside also.

 

[JohnDar]

The air return on my 3670 is up above the kitchen cabinets. It feeds down between the wall studs into the wide open basement. The returned air enters the furnace via the grating on the top and sides. Unlike the air return in a house, there is no direct ducting back to the furnace, so what is the value of putting a filter there??

 

[RuralPastor]

The air return on my 3670 is up above the kitchen cabinets. It feeds down between the wall studs into the wide open basement. The returned air enters the furnace via the grating on the top and sides. Unlike the air return in a house, there is no direct ducting back to the furnace, so what is the value of putting a filter there??

Good point, for your situation. My only source of return air is through the front grille, below the refrigerator. All other openings are small and restrictive (ex: pipes penetrating to underbelly, etc). The filter catches any dust particles in suspension through out the RV. The upside to a filter in this location is sound dampening.

 

[RuralPastor]

I have "heard" that it's not a good idea to install a filter. I think it was on the forum. You might want to call HL service and ask about it. I could be wrong. I agree with Chopper, unless you can completely seal off the area around the heater plenum, you wasting your time. These heaters draw air from outside also.

The only outside air intake is for combustion air. This is to eliminate any possibility of oxygen depletion. All other air is recirculated from the cabin. Maybe your model is different? As for sealing the heater plenum, yes, it would be ideal to have it completely sealed. The pressure drop across a standard filter would be negligible, unless plugged.

 

[ChopperBill]

The air return on my 3670 is up above the kitchen cabinets. It feeds down between the wall studs into the wide open basement. The returned air enters the furnace via the grating on the top and sides. Unlike the air return in a house, there is no direct ducting back to the furnace, so what is the value of putting a filter there??

Yeah, thats the way ours is. I think that the sure way of doing it would be duct it to that opening. Would like to cut down the dust, but I aint going to do it.