Propane versus Diesel

[jonnys_walkers]

We seem to have the same issue as others with off-season camping and heating with propane.
We find that the propane heat is very wet, so the windows and walls sweat.
Since the toy-hauler has a fuel cell I am considering installing two of the D5's to replace the propane furnace:
http://www.espar.com/fileadmin/data/...Spec_sheet.pdf

Has anyone else installed one of these or given any consideration to install one or two?

John

[RPAspey]

Unless you have a radiant propane heater, an RV propane furnace is a sealed unit. Outside air into combustion chamber then exhausted out. Thats why there are two openings in the wall plate on the outside of the RV. No combustion air is exhausted into the rv. The windows and walls sweat due to moisture that is exhaled and from cooking condensing on cold surfaces.

[RhoZeta]

Originally Posted by RPAspey

Unless you have a radiant propane heater, an RV propane furnace is a sealed unit. Outside air into combustion chamber then exhausted out. Thats why there are two openings in the wall plate on the outside of the RV. No combustion air is exhausted into the rv. The windows and walls sweat due to moisture that is exhaled and from cooking condensing on cold surfaces.

X2

the furnace is a heat exchanger, nothing from burning propane (should) enter the RV. The wet is from you.

[garbonz]

Better to just get used to the condensation, which is due to the low Rvalues of the windows and walls in RV's Try not to breathe to much or make food.


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[VinceU]

Very important to vent outside during cooking or showering, prevent mold!

[RPAspey]

We crack open the headboard window when heading to bed. That helps a bunch with condensation. I also sleep better with the fresh air too.

[caper]

Try using a dehumidifier, you will find the unit will feel warmer and have little to no moisture inside the unit.

[mark0224]

X2 on the dehumidifier, last March I decided to get an early start on doing some Mods and turned the dehumidifier on with the furnace, so I could work in comfort. When I was done I turned the furnace off but left the dehumidifier on for a couple of hours then went out and retrieved it so it wouldn't freeze. Never had any wall sweats or condensation on the windows. One day I even went out and shampooed the carpets, left the furnace and dehumidifier on till carpet was dry still no condensation.

[jonnys_walkers]

I can run the propane heater parked in the yard uninhabited and the windows and walls are covered with moisture, not from cooking or people breathing.
When boondocking dehumidifiers are not an option.

Thanks for the input.

[VinceU]

I might seriously be thinking about having some expert check air quality in your unit, it just ain't right with all that moisture. CO and CO2 gas may present w/the moisture.

[trbomax]

Originally Posted by jonnys_walkers

I can run the propane heater parked in the yard uninhabited and the windows and walls are covered with moisture, not from cooking or people breathing.
When boondocking dehumidifiers are not an option.

Thanks for the input.

I would look for a leak or rust out in the heat exchanger or where the exhaust on the furnace connects to the wall exhaust.Of course to pressure test the heat exchanger you will have to remove the furnace and the sheet metal around it.

[jonnys_walkers]

I guess I should have mentioned we live in the rainforest where our annual rainfall is 40 inches a year.

[funfinder5]

Changing your fuel source for heat is not going to change your condensation issue. Both this D5 and your propane furnace produce heat by a heat exchanger, same technology just different fuel. The D5 is more efficient only because there is more energy (BTU's) per gallon in diesel than propane... About 52% more in fact.

-Sean

[caper]

When boondocking you could try using damp rid or some other type dry dehumidifying compound.

[garbonz]

Originally Posted by funfinder5

Changing your fuel source for heat is not going to change your condensation issue. Both this D5 and your propane furnace produce heat by a heat exchanger, same technology just different fuel. The D5 is more efficient only because there is more energy (BTU's) per gallon in diesel than propane... About 52% more in fact.

-Sean

Dat's the truth. Nuff said. Maybe you have a source of moisture like a leak that is adding water to the inside. PLUS the R-values are very low and this the walls and windows are cold. Dew point is a function of temperature of the surface.


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[jk510]

As you said you live in a very damp, humid location so there is already a lot of moisture in the air. When you heat it up it's still damp but now warmer. When that warm, humid air contacts a still cold surface like the windows you're going to get condensation. The same principle as a cold glass of ice tea on a warm summer's day.

[garbonz]

Originally Posted by jk510

As you said you live in a very damp, humid location so there is already a lot of moisture in the air. When you heat it up it's still damp but now warmer. When that warm, humid air contacts a still cold surface like the windows you're going to get condensation. The same principle as a cold glass of ice tea on a warm summer's day.

Sort of.

Condensation is a function of the temperature of the surface and the amount of moisture in the air, regardless of the air temperature. The amount of moisture in air in absolute terms is expressed as grains of moisture, is independent of temperature. Condensation occurs when the temperature drops below the dew point at the surface and the air at the surface cannot hold the moisture any longer and water droplets form. In an RV, the cold surface caused by the low R values, make condensation worse than in a typical house. AND in a house, the lower R value of windows cause the condensation to occur there sooner than walls, something most of us observed.

Lot of more complexity to this subject, but this is the basics.

In order for condensation to form there has to be some moisture in the air, and a cold surface (relative to the air) for it to form on.


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[donanddona]

I find most moisture is found when we close the windows due to cooler temps. This moisture collects on window ledging and I need to paper towel daily. Untill, I got a whole house dehumidifier, it does a fantastic job. It has a led read on humidity levels and will auto start and auto stop at your desired setting. During rainy days I run it in constant mode. I dump the collection tank daily.

[Witch Doctor]

Garbonz, gave a pretty good answer, but most will tell you it pour circulation and cooking and showering and washing dishes and most of all bad insulation.
What is condensation?
Condensation is the process by which water vapor becomes a liquid. The air in our atmosphere contains anywhere from 0 to 4 % water vapor. This water vapor will remain in the air until either 1) so much water vapor is added to the air that it becomes saturated and can no longer hold the water vapor, or 2) the temperature of the air drops low enough that the air can no longer hold the water vapor. In either case the water vapor turns into liquid and forms on a surface as condensation.

What does it indicate?
When you see condensation forming on your windows it is a warning that there is too much water vapor in the air of your home or that there is insufficient air circulation next to the windows on which the condensation is occurring.

What causes condensation?
Condensation is caused by the air temperature becoming too low to hold the water vapor that is in it. The factors involved in condensation are as follows:
1. The amount of water vapor in the air of the home (measured in relative humidity).
2. The circulation of the air within the home.
3. The air temperature. Both in the home and outside.

The air in a room contains water vapor. The amount of water vapor in the air varies and is commonly expressed in terms of relative humidity. Relative humidity is the measure of the amount of water vapor actually in the air compared to the maximum amount of water vapor the air can hold at that particular temperature and pressure. The fundamental principle concerning air and relative humidity is: the warmer the air temperature, the greater its capacity for holding water vapor. When warm air in a room comes in contact with a cold surface the air around that surface begins to cool. As it cools its ability to hold water vapor decreases. Eventually, it reaches a temperature at which it can no longer hold the water vapor. This is sometimes referred to as the dew point. When the air reaches this point the water vapor begins to condensate, forming as tiny droplets of water on the cooler surface. Often times the glass in your windows is the coolest visible surface and this is why you may see condensation develop there first.

[techntrek]

A liter of water per person per day, between perspiration and exhalation. Stick 3 in a camper overnight (8 hours) and you have a full liter on the walls/windows/ceiling if it is sealed up and the A/C isn't running.

If the A/C is off, always keep a window and the bathroom vent cracked open to create a convective airflow to get the moisture out. I've camped in 8 F with a window and vent open slightly.