New Heater: Condensation problems - Fiberglass RV
Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 02-20-2011, 07:44 PM   #1
Senior Member
 
Francesca Knowles's Avatar
 
Name: Francesca Knowles
Trailer: '78 Trillium 4500
Jefferson County, Washington State, U.S.A.
Posts: 4,669
Registry
Question New Heater: Condensation problems

Can anybody explain to me how my old gravity feed (no fan) heater got rid of the condensation that's the main byproduct of propane combustion? The catalytic heater with which I replaced it puts out a lot more heat on a lot less fuel, but I'm having condensation problems, especially in colder weather.
I went with the catalytic heater mainly because I was determined to avoid the electricity drain (and noise) of the fans required on new conventional heaters. I'm rigorous about venting, and for circulation have mounted atop the heater an Eco-Fan (powered by the heat, and absolutely silent : Amazon.com: Caframo Ecofan Original, Black with Nickel Blade: Health & Personal Care )
The system works like a dream EXCEPT for the fact that I'm getting more condensation on the walls and windows than I did with the old heater. I'm wondering if the double-pipe design of the old stack had anything to do with vapor discharge.
Any illumination would be greatly appreciated.
Thanks!
Francesca Knowles is offline   Reply With Quote
Old 02-20-2011, 08:22 PM   #2
Senior Member
 
Gina D.'s Avatar
 
Trailer: Former Burro owner and fan!
Posts: 9,015
Registry
I don't understand how the catalytic process works, so I have no explaination for you on that one.

I have noticed a significant reduction in condensation with my Blue Flame heater that I replaced my Wave 6 with, however. It has been "Pacific Northwest" style wet weather here the past few days..temp drop, rain rain and more rain, and I didn't even get a drop on my windows using the blue flame. The Wave 6 would have made it like a sauna in here under those conditions.

http://www.fiberglassrv.com/forums/f...mmy-44647.html Read all about it here
Gina D. is offline   Reply With Quote
Old 02-20-2011, 10:21 PM   #3
Senior Member
 
Trailer: 2008 21 ft Bigfoot Rear Bed
Posts: 629
I think that a gravity heater burner’s intake and exhaust are external and warm air, generated by the heat exchanger, is circulated without a fan, just gravity (warm air goes up) inside the trailer. I would expect that with catalytic heater you will get a lot of water inside the trailer, all exhaust gases (H2O and CO2) stay inside the trailer.
George.
GeorgeR is offline   Reply With Quote
Old 02-20-2011, 11:21 PM   #4
Senior Member
 
Francesca Knowles's Avatar
 
Name: Francesca Knowles
Trailer: '78 Trillium 4500
Jefferson County, Washington State, U.S.A.
Posts: 4,669
Registry
Does the original gravity flow heater have a heat exchanger? Can you tell me how that works?
Is there anything you can suggest about venting? Is there any way I can direct the exhaust outside?
I still have the old heater- might the stack and shroud be employed to "encapsulate" the gases emanating from the new heater?
p.s.
what's a "Wave Heater"?
Francesca Knowles is offline   Reply With Quote
Old 02-21-2011, 12:45 AM   #5
Senior Member
 
Trailer: 2008 21 ft Bigfoot Rear Bed
Posts: 629
Catalytic heaters (Wave) and blue flame heaters are designed not to be vented. You have to allow for sufficient air exchange within the heated space to provide oxygen to the burner but this level of fresh air will not remove water vapors. Most of these no vent heaters have an oxygen sensor extinguishing the pilot flame in case of low oxygen level. To eliminate byproduct of combustion, water, I would suggest to go back to heat exchanger based heater.
George.
Attached Thumbnails
Heating.jpg  
GeorgeR is offline   Reply With Quote
Old 02-21-2011, 10:36 AM   #6
Senior Member
 
Francesca Knowles's Avatar
 
Name: Francesca Knowles
Trailer: '78 Trillium 4500
Jefferson County, Washington State, U.S.A.
Posts: 4,669
Registry
Boyoboy, is one picture EVER worth a thousand words! Your diagram succeeded in explaining to me what my poor engineer husband has been patiently trying to get across.
NOW I get it! Thanks!
Still...
I really like the quiet, lower operating cost, and electrical independence (fan generates its own power) of this system. What if I were to enclose it behind a metal plate, supplying outside air / exhaust, thereby isolating it from the interior? Would I be making it into a sort of heat exchanger? Wouldn't dryer air FEEL warmer, thus offsetting heat loss out the vents?
Francesca Knowles is offline   Reply With Quote
Old 02-21-2011, 01:23 PM   #7
Senior Member
 
Gina D.'s Avatar
 
Trailer: Former Burro owner and fan!
Posts: 9,015
Registry
a Wave heater is the brand name for the most popular cat heaater.. Wave 3, 6 and 8. I don't know what brand you have.

I "sort of" did what you are suggesting above with my Wave 3 install in my 13 foot Burro. I utilized the vent tubes from the old powered cat heater in it to supply fresh air inside 100 % of the time.

Didn't help with the condensation much.
Gina D. is offline   Reply With Quote
Old 02-21-2011, 01:43 PM   #8
Senior Member
 
Francesca Knowles's Avatar
 
Name: Francesca Knowles
Trailer: '78 Trillium 4500
Jefferson County, Washington State, U.S.A.
Posts: 4,669
Registry
Was the face of the heater still open to the room?
I'm thinking of trying to block the vapor by putting the unit more or less inside a (vented outside ) box, the metal face of which would then act as a radiant heater.
What do you think?
While I have your very kind attention, might I ask what kind of trailer you're full-timing in?
I see by your tag you used to have a Burro, but it doesn't indicate what you have now.
I'm wondering if your unit might be better insulated than my Trillium, whose walls get mighty cold, aggravating the condensation problem.

Thanks!
Francesca Knowles is offline   Reply With Quote
Old 02-21-2011, 08:53 PM   #9
Senior Member
 
Gina D.'s Avatar
 
Trailer: Former Burro owner and fan!
Posts: 9,015
Registry
Sadly, I am no longer in a fiberglass rig. I did fulltime in a 17 foot Burro, and it was perfect for me.. but I have pets and it wasn't working for them.

I am in a Kit Companion stick built, with all the pitfalls of one. It probably is better insulated, yes.

I am not sure your idea would be safe. The radiant heaters do get hot on the face and would probably heat up your enclosure too much.
Gina D. is offline   Reply With Quote
Old 02-21-2011, 10:03 PM   #10
Member
 
Russell A's Avatar
 
Name: Russ
Trailer: In the market
Pennsylvania
Posts: 59
Warning. I should have mentioned back the day after Christmas that I almost was overcome by low oxygen in my 6x10 utility trailer as I had my blue flame heater on and went to sleep before going to my sons in laws house. I was taking a nap and had the blue flame on and about and hour after falling asleep I awoke as I was getting a little chilly and woke up to find the heater off. I immediately thought I was out of propane and checked but the tank was still partially filled and came back in to check the settings and found that it was in the on position. I had a headache the rest of the day. The next day I had the new Atwood installed.

I do know that God has been watching over me.
Russell A is offline   Reply With Quote
Old 02-21-2011, 11:03 PM   #11
Senior Member
 
Trailer: 2008 21 ft Bigfoot Rear Bed
Posts: 629
Quote:
Originally Posted by Russell A View Post
Warning. I should have mentioned back the day after Christmas that I almost was overcome by low oxygen in my 6x10 utility trailer as I had my blue flame heater on and went to sleep before going to my sons in laws house. I was taking a nap and had the blue flame on and about and hour after falling asleep I awoke as I was getting a little chilly and woke up to find the heater off. I immediately thought I was out of propane and checked but the tank was still partially filled and came back in to check the settings and found that it was in the on position. I had a headache the rest of the day. The next day I had the new Atwood installed.

I do know that God has been watching over me.
Many, many years ago I almost ended my life by CO (Carbon Monoxide) poisoning, different circumstances, bur CO is CO. Personally I would stay away from either blue flame or catalytic heater inside any living/bedroom quarters. In my garage I have blue flame heater but there is sufficient air flow for fresh air and exhaust and I don’t sleep in the garage.
George.
GeorgeR is offline   Reply With Quote
Old 02-22-2011, 01:29 AM   #12
Senior Member
 
Francesca Knowles's Avatar
 
Name: Francesca Knowles
Trailer: '78 Trillium 4500
Jefferson County, Washington State, U.S.A.
Posts: 4,669
Registry
Quote:
Originally Posted by Russell A View Post
Warning. I should have mentioned back the day after Christmas that I almost was overcome by low oxygen in my 6x10 utility trailer as I had my blue flame heater on and went to sleep before going to my sons in laws house. I was taking a nap and had the blue flame on and about and hour after falling asleep I awoke as I was getting a little chilly and woke up to find the heater off. I immediately thought I was out of propane and checked but the tank was still partially filled and came back in to check the settings and found that it was in the on position. I had a headache the rest of the day. The next day I had the new Atwood installed.

I do know that God has been watching over me.
Ironically, I had a similar bad experience with my old gravity heater- in my case, CO ( incomplete combustion) backgassing into the trailer. That's what led me to replace it.
Sounds like your low oxygen sensor shut the flow off like it was supposed to, luckily!
I don't have a problem with low oxygen. The Ecofan depends on heat differential between the fins and the base to generate its electricity. The cooler the fins, the faster it turns, and it's supplied with cooler outside air which it moves at about 100 cfpm. In my case, that means that I'm replacing the interior air every five or six minutes. I also have plenty of venting, though (correct me if I'm wrong) a properly maintained catalytic heater produces little besides CO2 and.......
That pesky water!
The main problem is that it condenses on the walls and gets bedding, etc. wet. It seems to me that the only way to control it is to prevent its entry in the first place, which means isolating the flame from the room, which is apparently how "heat exchanger" type heaters work. (Thanks, George R.!)
Unless I could figure out a way to CAPTURE and use the water.....Hmmm.....distilled water.....I like it!
Francesca Knowles is offline   Reply With Quote
Old 02-22-2011, 12:55 PM   #13
Senior Member
 
Roger C H's Avatar
 
Trailer: 2009 Trillium 13 ft ('Homelet') / 2000 Subaru Outback
Posts: 2,222
Registry
I can't imagine how much water you would get burning fuel INSIDE the heated space. We get plenty from just breathing in our Trillium. We always leave one or two windows cracked and the roof vent open just for that problem. In the desert, there is no problem, but in the soggy NW, it is a constant fight against moisture, and we use an electric heater which generates no water whatsoever.

I found a good discussion about catalytic heaters:

http://www.rverscorner.com/catalytic.html

I just makes sense. Catalytic heaters, even if they generate NO carbon MONoxide, do generate carbon DIoxide and water. You need oxygen to survive, not carbon dioxide. Carbon monoxide is deadly poison because it actually takes oxygen from your body. While carbon dioxide doesn't do this, your body cannot use the oxygen it contains, so, instead of being poisoned, you merely suffocate.

Catylitic heaters consume fuel and oxygen. Humans need oxygen to survive. Are you willing to trust your life to a low oxygen sensor?
__________________
A charter member of the Buffalo Plaid Brigade!

Whether you think you can or think you can't, you're right.
Roger C H is offline   Reply With Quote
Old 02-22-2011, 02:24 PM   #14
Senior Member
 
Francesca Knowles's Avatar
 
Name: Francesca Knowles
Trailer: '78 Trillium 4500
Jefferson County, Washington State, U.S.A.
Posts: 4,669
Registry
I certainly would never stake my life on a low oxygen sensor.
That's why my heater has a permanent, silent,electrically independent, fan-forced supply of 100 cubic feet per minute of fresh, outside air. Not to mention additional venting of the interior. (4500 interior space: 500 cf= total air replacement every five minutes).
The hyperefficiency of catalytic combustion makes the production of CO unlikely, but as an abundance of caution I maintain a CO detector. It hasn't indicated the smallest trace of CO since the removal of the gravity feed heater.
I should say that my wording of my question sounds as if this is a newly installed heater. It's not. I've been using it for three years as described, in all kinds of weather, from sea level to 6000 ft.
As many as four people have slept in the trailer, with heat. Not so much as a headache! I think it's been pretty thoroughly field tested.
Since I meet or exceed every safety standard-without exception- I'm perfectly confident that it's as safe as the manufacturers purport it to be.
My problem is the extra water.
All of your input has been most helpful, and I'm tending toward an encapsulating solution.
Francesca Knowles is offline   Reply With Quote
Old 02-22-2011, 03:47 PM   #15
Senior Member
 
Trailer: 2008 21 ft Bigfoot Rear Bed
Posts: 629
With 5 min cycle time for total air volumes exchange it seems that the water build-up should be unlikely. Caframo Ecofan advertises air flow up to 100 CFM most likely at the optimum conditions. If temperature is not optimum and ducting has leaks perhaps you are not exchanging air at 100 CFM but much less. I would not be surprise if your Ecofan is exchanging air within a few CFM, sufficiently low to have water build-up issue.
George.
GeorgeR is offline   Reply With Quote
Old 02-22-2011, 05:18 PM   #16
Senior Member
 
Trailer: 2002 19 ft Scamp 19 ft 5th Wheel
Posts: 3,640
Send a message via Yahoo to Darwin Maring
George said: I think that a gravity heater burner’s intake and exhaust are external.

That is true. It had a chimney inside a chimney. One took in fresh air and the other was the exhaust. If it did not do that, you would have had a gas chamber and you would have monoxide yourself.

Your CAT heater burns at a better combustion level thus non-vented HOWEVER it can deplete ALL The Oxygen and suffocate you. Not Monoxide poisoning but the same results (DEAD).

Make sure any combustion (Fuel Burning) heater has a low oxygen shut off or don't use it.
Darwin Maring is offline   Reply With Quote
Old 02-22-2011, 06:01 PM   #17
Senior Member
 
Francesca Knowles's Avatar
 
Name: Francesca Knowles
Trailer: '78 Trillium 4500
Jefferson County, Washington State, U.S.A.
Posts: 4,669
Registry
I'm pretty sure I'm getting maximum efficiency from the Ecofan.
Via an outside duct, it draws fresh (also wet?) air into the trailer and blows toward the room. I'm able to keep it at top speed even on low heat setting by concentrating (a) the heat at the base and (b) the incoming cooler air at the fins. The effect is increased by the presence of an aluminum barrier between these two parts of the fan which prevents rising heat from warming the fins. Outgoing air openings: 100 cu. in. m/l.
And I still get plenty of heat!
I think the basic problem is the lack of real insulation in the trailer. Those cold walls are magnets for water vapor. Since all the moisture produced by combustion (and people) collects in the room it's likely condensing before it has a chance to escape via the vents and windows.
Figuring out how to insulate the trailer seems a lot more complicated to me than eliminating a moisture source by isolating the lit surface behind a heat-conductive barrier.
If I move my converter, the whole shootin' match will fit fully inside the compartment beneath the closet, and I'd provide intake/ output venting there.
Isn't that a little like a heat exchanger?

Thanks!

P.S.
I'll bet it's no coincidence that at least five people in this thread (including me) are Pacific Northwesterners. Who knows more about The Dreaded Damp than us Mossbacks???
Francesca Knowles is offline   Reply With Quote
Old 02-22-2011, 06:10 PM   #18
Senior Member
 
Trailer: 2008 21 ft Bigfoot Rear Bed
Posts: 629
Catalytic heaters will generate CO at low oxygen level. See the chart from this study http://www.cpsc.gov/library/foia/foia05/os/co03.pdf
George.
Attached Thumbnails
www.cpsc.govlibraryfoiafoia05osco03.pdf - Google Chrome 2222011 40311 PM.jpg  
GeorgeR is offline   Reply With Quote
Old 02-22-2011, 06:40 PM   #19
Senior Member
 
Matt in SV's Avatar
 
Trailer: U-Haul VT16
Posts: 987
Registry
Platinum Cat makes fully vented catalytic heaters.

Welcome Page

They aren't inexpensive, and they do draw 6 watts of power when running.

Regards,

Matt
__________________
Planning our next Escape!
Matt in SV is offline   Reply With Quote
Old 02-22-2011, 07:42 PM   #20
Senior Member
 
Joe Z's Avatar
 
Trailer: 16 ft Casita Spirit Deluxe
Posts: 1,043
Quote:
Originally Posted by Matt in SV View Post
Platinum Cat makes fully vented catalytic heaters.

Welcome Page

They aren't inexpensive, and they do draw 6 watts of power when running.

Regards,

Matt
My conversion math stinks so does 6 watts divided by 12 volts equal .5 amps?..... If so that nice and vented to boot.
does anybody know the price on the 3P-12 or the 6P12?____ Can't find a price list anywhere
Joe
Joe Z is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Condensation Problems Michele B Care and Feeding of Molded Fiberglass Trailers 0 06-19-2010 02:58 AM
Condensation.... FredericL Problem Solving | Owners Helping Owners 4 05-13-2009 04:57 PM
Condensation Valerie G Problem Solving | Owners Helping Owners 2 01-22-2008 05:23 PM
Condensation bdiscount Care and Feeding of Molded Fiberglass Trailers 37 04-26-2006 03:15 PM
hot water heater problems Lou & Lora E. Problem Solving | Owners Helping Owners 1 12-30-2005 07:00 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 02:25 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.