We're going to try to quiet that heater

OneMoBear · 02-11-2011, 02:04 PM

We are having a 38 degree heat wave today so we pulled out the TM to take a look at the heater compartment. This is in reference to this:

http://www.rv.net/forum/index.cfm/fu...g/1/page/2.cfm

Please go down to the post with the picture.

The first picture I'm posting just shows what appears to be vents that should not be obstructed, on the top and both sides. Please feel free to jump in on this.

Second: Surprise! It is cockeyed it the compartment! There's gobs of room on one side and just about an inch on the other, much tighter toward the outside wall than the inside wall. I'm nothing if not creative . . .

Any thoughts about "Too close!" (The foam is fire rated) How about putting the insulating foam on the other side of the divider?

Third and fourth show (from inside and out) that there is a gap on one side that is big enough that I can run my finger from top to bottom between the cover and the base of the dinette seat base. I'm not getting any brilliant ideas here . . .

I'm about ready to order the insulating foam and am tossing this out for wonderful advice!

Just for the record, it's not just TM with noisy heaters. Our Bounder was at least this bad!

Malinda

scrubjaysnest · 02-11-2011, 02:23 PM

Which thread was that in, the link took me to the forums sign in page? Don't know what the foam might do but most likely not a lot for noise. The bulk of the noise is usually from the fans and motor.

02-11-2011, 02:45 PM

I agree. Not really sure that will damp the noise from the heater fan that much. A lot of it seems to be coming right out of the vents.

In the thermostat/heater thread cochise mentioned this site:
http://rvtravel.com/blog/rvnow/2007/...ic-heater.html

Which uses one of these vented catalytic heaters: http://www.ventedcatheater.com/2.html

Catalytic, especially with a quiet quiet ventilation fan sounds good to me. Not sure where I'd put one of those in my Elkmont though.

OneMoBear · 02-11-2011, 03:03 PM

I'm confused. That link works for me. Maybe #6 from here http://www.trailmanorowners.com/foru...hlight=digital will work better. We know that most of the noise comes from the fan and motor but we're willing to drop $30 to see if this mod helps.

I think I've attached the picture from that post and the text is "Here’s what we did to quite our furnace. 58 to 51 dBA, a 7dBA noise reduction! McMaster-Car #5692T13, 1" Thick Acoustical Polyureathane Foam Absorption Material, 2 linier feet for ~ $20. Meets flammability standard FMVSS-302."

We just don't have the nerve for a catalytic heater. We bought a portable one and use it in the garage when we are WIDE AWAKE.

Malinda

**Bill** · 02-11-2011, 03:29 PM

Before you start putting foam slabs here and there, be sure that you have the Installation Manual for your exact furnace in front of you, and be sure that you read, understand, and obey all of the minimum clearance requirements. There is a specified minimum clearance on all 6 sides of the furnace, and you must not intrude into that space!

It's kind of like the setback requirements when you build a house, except that if you do it wrong, it isn't the Town that comes after you, it is the undertaker.

Bill

OneMoBear · 02-11-2011, 03:46 PM

Gotcha! If we wanted the undertaker to come after us, we'd just go with the catalytic heater. Way less work.

Seriously though, there are two "pipes" going to the outside from the back of the heater. I'm guessing that one is fresh air and one is exhaust. No, I don't want to "guess" when we actually change something and will dig out the book but just a simple "Yes, those vents pictured in photo #1 do this" would be great.

Malinda

Wavery · 02-11-2011, 04:35 PM

Like Bill said, check the installation manual and see what the minimum clearances are. If the minimum is 3" on the sides and you have 5" (which you don't) you could put 2" of foam (which I don't think you can).

I think that you might be good putting your foam around the front of the heater, where it comes though the wall. You may even have some extra clearance between the bottom of the cushion and top of the heater but I think the cushion is about as good a sound barrier as you're going to get.

In post #1, pic#2, you have a wall (at the top of the pic below the tape that says "5352"). You could put your insulation on the other side of that wall. The opposite wall looks like it has twice as the distance between the heater and the wall. If the minimum distance is the same on all sides (and TM adhered those minimum distances) you "should" be OK to glue foam to that wall.

Whatever you do, be sure that the adhesive you use is a good one. 3M has some spray trim adhesive that you pray on both surfaces, let it dry, then put them together. I know that stuff works.

If your foam happens to lose contact and fall against the heater, that could be a very bad thing.

Those vents are to keep the heat exchanger (inside the heater case) from over-heating the electrical circuit panels that are located back there. If they don't get enough natural air flow, the heater will shut-down from over heating (you hope).

The reason these heaters make so much noise is because they use a 4-blade aluminum fan blade on a small shaft. There is no noisier fan made than that. If you can find a heater with a squirrel cage type fan with a bearing on both sides of the fan (like most home forced-air furnaces have), that would be much quieter.

Please keep us posted on what you find out. I may like to do the same thing. The thing about sound deadening is that you don't necessarily have to "block" the sound. Sometimes sound deadening put in the right place can "absorb" a lot of sound.

BTW.....the pic in post #4.......I may be wrong but I think the guy glued the sound deadening foam on upside down. I'm pretty sure that the open cell part of the foam is designed to absorb the sound. I think that the smooth side is designed to be glued against a flat surface. It seems to me that the sound would just bounce off of that shiny smooth surface. That would pretty much defeat the purpose of using sound deadener. I would think that the sound entering the open cells of the foam would get trapped in the foam and die (thus the term sound "deadener")

scrubjaysnest · 02-11-2011, 05:45 PM

I looked at the last pic you posted, that is a ducted system like we have in the outback and the one piece of foam at an angle looks like it blocks the return. We don't have that setup in the TM. And yes the two pipes coming into the back of the heater are intake and exhaust. Like Wayne said the fans only have the motor bearings for support and thats why to noise or the bulk of it. Modern catalytic heaters have both tip over and low o2 shut sensors and are very safe. Also far more efficient then what comes with the TM. We used a Mr Buddy catalytic propane heater for 6 months last year with no problems. It wasn't run at night. Thats what your dogs and cat are for

OneMoBear · 02-12-2011, 07:23 AM

We really appreciate all of the great advice. Wayne, that's funny. You're probably right. "Widely used to reduce noise levels within given spaces, these lightweight acoustical foams absorb sound waves through air cells in the material and then convert them into heat energy. A material's Noise Reduction Coefficient (NRC) represents the amount of sound it can absorb. The higher the NRC value, the more efficiently it absorbs sound; a material with an NRC value of 1 is the most sound-absorbing material you can get."

I have been searching online for the information on clearances etc. as our manual is in the wardrobe and the TM is back in the garage

We just may have to come up with a better plan there . . .

We'll be certain before we make it happen but I wanted to see what I could find before I ordered the foam. I found this: http://www.brwholesale.com/itemNotes...ice_Manual.pdf The rubber seems to hit the road around page 17 and they way I'm reading it, we should be fine.

I'm not really seeing what I would call "clearance" as in don't get it closer to the wall than this. It's probably there somewhere . . . Like I said, it's only about an inch away from the wall on that one side. I think we'll just give it a shot on the other side of the wall there.

I'll keep you posted

I've got a dB app on my Iphone so I should be able to give some decent feedback.

Malinda

OneMoBear · 02-12-2011, 07:36 AM

Quote:

Originally Posted by scrubjaysnest

Modern catalytic heaters have both tip over and low o2 shut sensors and are very safe. Also far more efficient then what comes with the TM. We used a Mr Buddy catalytic propane heater for 6 months last year with no problems. It wasn't run at night. Thats what your dogs and cat are for

LOL! We don't care how loud the heater is during the day. We can yell at each other till the cows come home.

The problem is we will camp in very cold temps as long as we are able, often without hookups. (Can't wait for Peaceful Valley and Dick's Campground to open!) We will have to use this dang heater while we are trying to sleep.

Malinda