Furnace filter

[floatflyer]

Maybe it's my technical ineptitude but I tried to search threads about furnace filters and they lead to ad !inks not truly useful information. Does the furnace air intake have a cleanable or replaceable filter element and where is it. I can hear the furnace blower running inside or behind wall panels but the panels don't look very easy to remove. More correctly they can be removed but would be nice to replace them too so they look something like they did at the start of the project. Any info and advise is appreciated. Given the amount of dust overall I can imagine the amount of dust there is probably significant and getting worse.

[GaryWT]

Interesting, the AC unit has a filter that you can take off and clean but I do not think the furnace does. In all my years of camping I have never changed one and don't recall the question being asked. When we had a forced hot air system in the house we did but never in the RV.

[bsmith0404]

Originally Posted by GaryWT

Interesting, the AC unit has a filter that you can take off and clean but I do not think the furnace does. In all my years of camping I have never changed one and don't recall the question being asked. When we had a forced hot air system in the house we did but never in the RV.

x2....now you have me thinking maybe I missed something. I tend to think if it has a routine maintenance requirement such as a filter cleaning/replacement it would be easy to get to/removable panel. Not a single RV I have ever owned has a furnace that is easy to get to.

[jkohler70]

You're going to get everyone scratching their heads. It does seem odd, considering the environment some camp in, that there is no filter protecing the furnace components.

[jsmith948]

The furnace fan is driven by a 12v motor so it can be used when shore power is not available. I think a filter on the return would restrict the air-flow causing the fan to work harder, drawing more amps, reducing the time it could be run off the batteries?

[allmi01]

I have never seen a filter on a RV furnace. I did however install one onthe louvered grill that sit in front of the furnace for 2 reasons.

1. makes it a little quieter working as a noise baffle.
2. using the the trailer a a full time residence and wanted to filter the dust a little before blowing it around the trailer.

Since the fit was anything but tight, I added some foam insulation to fill the voids. Used zip ties to attach the filter.

It did not reduce the air flow but did help the air quality a bit.

Since I no longer have that trailer, I can't post pics. Sorry.

Mike

[bsmith0404]

Originally Posted by jsmith948

The furnace fan is driven by a 12v motor so it can be used when shore power is not available. I think a filter on the return would restrict the air-flow causing the fan to work harder, drawing more amps, reducing the time it could be run off the batteries?

Probably part of the consideration behind it, but now it has me thinking about the dust accumulation on the fan blades. We've all seen what happens to blowers/fans, even filtered ones like in AC units. Now I'm thinking I at least need to clean the dang thing once or twice a year. Why do people need to point stuff out that creates more work for me Before it was out of sight, out of mind, now it's just out of sight.

[geo]

The air intake (for heated air distribution) are the cut-outs, or grating, that is the top of the furnace. Basically, one is pulling air out of the utility area and underbelly, heating it, and sending that air out for distribution. You cannot put a filter on the grate area as the furnace does heat up. Fire hazard! Before I first seasonly use the furnace, I sweep and wet wipe the dust from the furnace casing. But, no, there is no furnace filter.

Ron

[Tinbender]

Worked in the HVAC industry for 30+ years, sticks and bricks not RV.
A couple of observations.

Furnace air should be filtered so dust and pollen isn't recirculated through the conditioned space. A correctly sized filter area based on blower CFM produces very little air flow restriction. Where it becomes a problem is when filters aren't changed and the filter surface begins to load and retain the dust and increases the flow restriction.

The reason, in my opinion, that RV furnaces aren't equipped with filtration is because the manufacturers are cheap. They can save a few cents or a buck by not supplying and installing filtration. They also know that very little, if any, mechanical failure will result from this practice.

Air conditioning on the other hand can suffer expensive mechanical failure from lack of filtration by allowing the dust and dirt to plug the coil surfaces. This plugging reduces the air flow not allowing the air to remove the cold from the gas and this cold gas is sent back to the compressor causing icing and damage to the compressor. This damage would probably have to be repaired under warranty so they are a little more careful by adding just barely minimal filtration to the unit. By the way this filtration is
supplied by the AC manufacturer not the RV builder.

Like I said just my observations.
Tinbender

[golfpro]

there is no such things as a RV furnace filter. and do not attempt to install one either. you will restrict the air flow and burn up the motor fan on the unit. air for the combustion is drawn in from out side and no filter is needed.

[Fishhawk]

Originally Posted by golfpro

there is no such things as a RV furnace filter. and do not attempt to install one either. you will restrict the air flow and burn up the motor fan on the unit. air for the combustion is drawn in from out side and no filter is needed.

Huh? "air for the combustion is drawn in from out side and no filter is needed"

IMHO,
Outside air can be , and usually is dusty and loaded with pollens

RV design may dictate that a filter can't be used
But the fact remains, a filter is needed when circulating inside air

[jsmith948]

I think outside air is drawn in for for combustion. The air that's heated is drawn from inside the coach.

Sent from my HTC6525LVW using Tapatalk

On edit: This was already stated in an earlier post -my bad.

[Festus2]

Originally Posted by jsmith948

I think outside air is drawn in for for combustion. The air that's heated is drawn from inside the coach.

Sent from my HTC6525LVW using Tapatalk

x2 Outside air is drawn into the heat exchanger which in turn "heats" the surrounding cooler inside air. The cool air intake is the removable, louvered panel found at floor level in front of the furnace.

Any of the outside air drawn in through the air intake enters and exits via the exhaust from the heat exchanger. I don't think any of this outside air escapes from the exchanger into the room so you shouldn't have to be concerned with pollens or other pollutants "entering" the coach via the furnace.

[SkiSmuggs]

Originally Posted by jsmith948

The furnace fan is driven by a 12v motor so it can be used when shore power is not available. I think a filter on the return would restrict the air-flow causing the fan to work harder, drawing more amps, reducing the time it could be run off the batteries?

This is why there is not a furnace filter. And if not enough air flows, the heat output is reduced. I found this out when I ran my furnace with a recliner chair stored against the air intake.

[hankaye]

Howdy All;

I kinda like to think of my RV as Home. After all, for me, it truly is.
That said, I have a border Collie that shares the living space with me.
Dogs shed. Rascal thinks he's a dog but what he truly is, is a FUD (Fur
Dispersal Unit), and he is extremely good at it. I use one of those foam
filters like the one used for the AC inlet. I use some of the mini bungees
and some 3-penny finish nails to keep it in place. Once a month I pop the
louvered piece off and either vacuum or wash it out. Sometimes both,
during the Spring and Fall shedding seasons. Has worked fine so far
(touch [knock on] wood).

hankaye

[hankaye]

SkiSmuggs, Howdy;

Originally Posted by SkiSmuggs

This is why there is not a furnace filter. And if not enough air flows, the heat output is reduced. I found this out when I ran my furnace with a recliner chair stored against the air intake.

The spec. sheet for my furnace states that I need 144 sq.in. for proper air
flow. the louvered vent for mine is 22.5" X 10" or 225 sq.in. the thin foam I
use doesn't create much restriction hardly 81 sq. in. worth let alone more
than that... the recliner probably has a fabric skirt that got sucked up to the
louvered inlet vent and there was your basic problem..... the judicious use
of some common sense will allow for effective operation of the basic
equipment that Keystone has seen fit to equip us with.