Furnace Filter

[exav8tr]

Call me a dummy, BUT, I can't find a filter for the furnace. Is there one or not? If so, where is it? If not, Oh Well! '06 3400
RL

[Ozz]

Nope. I put a pleated filter in my return air. Can't imagine them not filtering the furnace.
Suggest all have them.

[illapah]

Oz, just wondering, is the filter on the room side or behind the grill? I have been thinking of this myself. Also, the air return can come from the storage side also. Did you seal this at all? Wonder if that would affect the heating of the storage area. Not wanting to hijack the thread, I think this is applicable.

[Charlie]

I thought about installing a filter in the return air but after further inspection it would not filter all. There is an opening that comes from the underbelly that makes it next to impossible. Every RV that I've owned has not had an air filter on the furnace return air.

[bsmeaton]

I've never had an RV that had a furnace filter.

[VanMan]

I never have had one either. I bought a foam replacement material like for the A/C and made one to put inside the return register (my Montana is probably unlike any other). It may not filter ALL, but it sure gets SOME !!

[CRUZIN 2]

We have installed air filters for the furnace in the last two rigs, and it does catch allot of dust. We live in our RV about 8 months out of the year.

[Ozz]

I put it inside the grill so you can't see it. The majority of return air comes from the space; isn't that where all the dust-dirt would be? I think so, If you desire to not filter, that is up to you.
It would not be practical (access and safety) to build a filter holder right next to the intake of the heater, so this is the best solution in my opinion.

[dsprik]

As per Aram in response to the thread on the double air returns that are now being put under the stairs in some Montanas, the air flow as is on my 3400 (2007 w/ single return) are critical:



An air filter (even a clean one) may restrict this air flow to a possibly unacceptable cfm.

[bncinwv]

That is interesting Dave, wonder if there is any possibility of increased CO because of decreased air flow. I wouldn't think so but Heating or A/C expertise needed fer sur here?? Ozz and other HVAC gurus, comments on this, please!! I guess this is as good an opportunity as any for us to remind ourselves to check our CO monitors regardless.
Bingo

[bigmurf]

I suspect a clogged filter would reduce the air flow and the SAIL Switch would not stay closed.

[bsmeaton]

Bingo, the furnace combustion air and exhaust are direct to the outside through the side vent (direct vent) with no crossover into coach. Restricted airflow in the return would only affect perfomance.

[Ozz]

The filter would not cause a problem, I guarantee it. Change it out when it gets dirty. I use a pleated filter, it is best, more area on the filter also.

[exav8tr]

Well, today I became filtered, Yep, I put that sucker under the stairs, Behind the grill, Just put several screws into the side supports to keep the filter in place. I bought a 16 x 20 and cut it in half so I still have another half to install in 2 - 3 months, or when it gets dirty. Will keep an eye on air flow for next few days. Thanks OZZ for the expert advice....

[Ozz]

Good deal, the furnace really doesn't get much protection, as there is just the heat exchanger, but the fan has cupped blades to move air. These blades fill with hair, dust, lint, small paper. When I change out a fan motor in a commercial space, (or a residential unit) I power wash the fan assembly, as the cupped blades are almost always 1/2, or all the way full of ...junk. cuts down the air movement by a bunch.
That is why we need to filter the air.
Oh, a plus is, that the air we breathe and live in, is filtered when the furnace is running.
In a stick home, if the fan runs all the time, as ours does; thermostat fan on 'on' all the time. The air in the home is filtered around 7 times an hour by the furnace fan.
I installed a 4" pleated filter in our home, with a UV light in the 'A' Coil plenum, to kill the little squiggles in there, because of Sue's asthma and numerous allergies.

[mgdg]

Ozz you hit the nail on the head, not only that you are filtering in your stick house with it in the "ON" position but you are running more efficeintly. In the summer I run mine on "ON" all the time with the AC and the AC unit doesn`t come on as often.

[PowellsMonty]

Ozz, does the UV kill more than the electric "Zapper" type filters?

[Ozz]

Mike the UV light is a sterilizing type of action taking place, and bacteria will be killed in it's light, the coils are in a wet environment, as is the insulation on the sheet metal around the plenum. You should see some of them, full of mold and slime...yuck.
The electronic air cleaners will clean the air by collecting any dry particulates.
Is that redundant; dry particulates??

[SlickWillie]

Hmmmm....this is one of the things I want to address in our unit. I did notice a couple weeks ago when we had furnace problems though that Suburban says something to the effect of the "the rv furnace is not approved for a filter". Where ours is located, under the fridge, it would be an easy mod. Seems like the ones that are filtered have proven Suburban wrong. Wonder why they say that? Liability issue?

[Ozz]

prolly