Making an rv furnace quieter

[ksbowman]

Every rv furnace we have ever had was noisy. Has anyone done something to quiet there furnace. I have considered trying to wrap the blower area in insulation. Anyone had any luck?

[Goostoff]

I added an electric fireplace under the TV in the living room, and run the cord through a weather tight electric box that I installed. This can be plugged directly into the post and places no additional load on the trailers electrical system. Then up in the bedroom we just have a small tower heater with a thermostat. This combination is nearly silent. We just turn the furnace about 5 degrees colder in case it gets cold enough that the electric system cant keep up but it very rarely ever kicks in. Now the A/C on the other hand is something I would like to figure out how to quiet down. That thing drives me crazy when I am trying to watch TV

[Blacklane]

Check the specifications for your furnace, usually stuck to the side of the unit, but certainly available online. It will tell you the minimum return air duct size, which is often 80 square inches. With that information, you can probably block-off most of the return-air grill except for 8 x 10 inches (80 square inches). Most RV grills are far bigger than that. Also check the specifications for minimum clearance. You may have enough room to add some fiberglass insulation as sound absorbent in the cabinet where the furnace is installed.

[myredracer]

2oldman wrote:
I'm not sure what the definition of 'loud' is for a furnace. Mine is fine. Electric space heaters are much louder, and annoying.

Agree. Portable electric space heaters are def. noisy due to the small propeller fan blades. Heaters with squirrel cage fans like the ones I used are waay quieter.

noteven wrote:
myredracer- I like your mod. I’d ask you how it’s done but then there might be a safety kerfuffle on the forum...

Forced air heat is like warming a rock with a hair dryer. It requires noise.

I boondock mostly. I use a Propane catalytic converter (Big Buddy) Not expensive, portable, quiet.

Requires some common sense “supplied by user.”

Here's a few pics. The one under the stove (Stelpro IIRC) was the exact width as the stove and all I had to do was remove a piece of wood between the stove and door below and it dropped right in. Each heater has it's own thermostat. The setup is just like in a house and is evenly heated throughout. The demand controller is under the dinette seating next to the converter/panel in the 4th pic and has a current sensing relay and the low voltage relays (24 VAC) for the t'stats. The bed & bath fans (King Pic-a-watt) are like in the last pic and you can see the squirrel cage fan. It has rubber vibration isolators which also helps. I ran all the wiring completely concealed in the ceiling and wall cavities. Looks like a factory install!

We never dry camp so this works well for us. Have never once tripped a 30 amp breaker. We're both hearing impaired and the TV is much easier to hear clearly without the furnace blasting away plus we sleep a lot better. Being an EE likely helped doing this mod... 🙂

[BarabooBob]

We were tent campers before RV and now TT. As long as we are comfortable with a jacket on, it's warm enough. We set the thermostat at 60 degrees and enjoy the heat. We spend most of our time outside hiking or enjoying the campfire. At night we turn the heat down to 50 and use sleeping bags to stay comfortable while we are asleep.
We seldom have hookups so we do rely on the furnace to keep the above temps. We consider the noise the price to pay to avoid getting uncomfortable.

[ksg5000]

Like many we use our furnace as backup when the electric heaters can't keep up ... if/when it kicks on we are usually cold enough that we appreciate the heat regardless of the sound. The initial firing of the furnace sounds is what wakes me - not sure how you quiet that down.

[2oldman]

I'm not sure what the definition of 'loud' is for a furnace. Mine is fine. Electric space heaters are much louder, and annoying.

[ksbowman]

Myredracer, We use electric heaters anytime we can and I agree they are very quiet. There are times though when we have no 120 to operate them and the gas furnace is used. You have a very good idea and if I can't quiet it down I may do the same as you.

[D_E_Bishop]

I am pleasantly surprised with how quiet my Adventurer heater and residential AC are. I don't think either one had been used much and the first couple of times we used them they made some noises they don't make now.

The return air for both are part of the bed pedestal and made from soft materials.

The heater cabinet must be lined too but the big thing is the burner makes very little noise, even outside it is quiet.

[Dutch_12078]

The majority of the sound from our two furnaces comes from the large cold air returns. I lined the area behind the grills with a sound absorbent material, and even blocked off a section of the over sized grill with the same material, being careful to still exceed the manufacturer's required minimum opening area and minimize restricting air flow. The sound level reductions were significant, although I didn't take any before/after measurements.

[noteven]

myredracer- I like your mod. I’d ask you how it’s done but then there might be a safety kerfuffle on the forum...

Forced air heat is like warming a rock with a hair dryer. It requires noise.

I boondock mostly. I use a Propane catalytic converter (Big Buddy) Not expensive, portable, quiet.

Requires some common sense “supplied by user.”

[Old-Biscuit]

Don't be surprised when furnace keeps tripping on 'high limit'

[time2roll]

Consider a two stage furnace that runs the fan on low when possible.

[myredracer]

I came up with a great solution. The furnace is now dead quiet... 🙂

I installed 3 permanent recessed electric heaters, one in bedroom, one in bathroom and one in kitchen/living area totaling 2KW. Very quiet.
Made my own demand controller that disconnects the heaters while an appliance(s) is running which draw current above a preset level (we are 30 amps). Works like a charm and has to be my favorite mod.

RV furnaces are dang loud. Don't miss it at all! I don't think there's anything that can be done. Need to follow manufacturers spec for clearances, air flow, etc. for safety reasons.