Condensation Problem on front window.

Google Eva Dry. They have some small units that work well. We have one that we sit on the dash between the curtains and the windshield and it does help keep the moisture down. A hint I read and was going to try. Spray windshield with water and then stick bubble wrap onto the glass. It will act as an insulation barrier. When the sun is out - remove and let sun in to warm things. Simple to reinstall - just spray glass again. I haven't tried this, but will as soon as I pick up some bubble wrap rolls. An older motorhome here has a map light that is between the curtains and windshield. They leave it on and it provides enough heat to keep the condensation off the windshield. We don't have one located to do that.

I don't know HVAC:h. We spend winters next to the Gulf and there is nothing as nice as a dehumidifier. Warms the place up some, and takes that damp feeling out of the furniture.

Seems like the old timers that grew up on Trailer Life magazine do the cracked vent idea process though. I think that came out with running a non vented propane heater and the moisture it would put out.

Don't know how a crack vent would ever pull the dampness out of the furniture though, and heat does rise so if you're trying to stay warm it seems counter productive.

Hi,

Basically I just used a bath towel to dry out the windshield when it got wet. Or a smaller dish towel, that I can hang on the oven door to help dry it out.

Or you can place one of your heaters near the windshield, and it will blow warm and very dry air across the windshield, keep the window warm, and prevent the condensation from happening there.

I would not bother with a dehumidifier, they are kind of expensive, while opening a roof vent while cooking is required, just leave it open about 1/4" all the time, you will bring in some dry outside air, and constantly let out some moist inside air through the roof top vent.

Air has a 'relative humidity' so the number of 'grains' of water that air can hold varies with temperature. So outside air with 85% humidity and 43F can only hold about 15 grains per cubic foot of air, while the 70F air that is leaving with 65% RH can hold about 200 grains of moisture per cubic foot. So you are bringing in much dryer outside air.

A dehumidifier has a electric compressor that cools the incoming air to about 40F on the first coil, then heats the air going through the condenser to about 85F, so that the air drops to about 15 grains of water (leaving it on the cold coil, just like in a HVAC system) then heats it back up to 85F where it can absorb much more moisture, and is very dry now. You just skip the electric compressor part by bringing in outside 40F air and exhaust the 70F moist air.

When I lived in Portland OR in my motorhome for one winter, I used a 25' long #12 gauge extension cord to plug in one of my electric heaters. I ran the cord into the basement, and through a fitting in my bedroom that the factory installed. Then I plugged in one heater there, running it on high heat. It draws about 12.5 amps. With the 30 amp RV service, I ran two other heaters on low heat output, and that kept it toasty warm inside.

At night, I would shut off the two other heaters, and just warm the bedroom. In the morning, I could run one heater on high - normally in the bathroom, while warming up the front of the coach. I did not use a coffee maker, or toaster oven. When running the microwave, I would shut off the heaters. I never tripped my 30 amp main breaker.

Good luck!

Fred.

Fleetwood Couple wrote:
There are no weep holes. This is the front windshield it's sealed up all the way around. The water was in the bottom frame of the window. I am going to see about locating a small dehumidifier. Not much left to run anything else. We're already shuting stuff off just to make coffee. 30 amp service is all we have.

Dehumidifier is the right answer, if you're living in the rig. 30 amps should be enough. I'm guessing you might be running an electric heater or two on the same line as the coffee maker. More then likely the line is a 15 amp breaker.

Good thing about a dehumidifier is if you can find a cheap used one in a second hand shop they usually are not very energy efficient and will throw off heat keeping you warm in the process.

Do as stated earlier: place old towels along the bottom to absorb the water as it runs off. You will not be able to completely stop it in cold weather. Some of the windows on my house sweat also. Control the moisture with towels and don't worry about it.

Ventilation will help. We usually leave a roof vent cracked an inch or so. Using an outside windshield cover will insulate the glass from the cold somewhat and having the glass warmer will reduce condensation.

There are no weep holes. This is the front windshield it's sealed up all the way around. The water was in the bottom frame of the window. I am going to see about locating a small dehumidifier. Not much left to run anything else. We're already shuting stuff off just to make coffee. 30 amp service is all we have.

Also make sure the weep holes are clear. 1/4" is quite a bit of standing moisture.

Yes, there is a product that will stop moisture inside your coach it's called a Dehumidifier! You can buy them at most RV Shops. It's the greatest device that I have purchased for my coach. I have my dehumidifier placed between my split windshields and I empty 3 to 4 inches of water out of it a week. Great Question!

The only thing that can stop condensation from forming on your windshield is proper ventilation. The problem is that in the Winter, most people want to keep things closed up. All of the moisture from your body, the shower, the kitchen, plus what is generated by your propane stove, remains in the coach and will be deposited on the coolest surfaces, which are usually your windshield. You will also see moisture on your other aluminum window frames, even if the glass is dual pane.
Using electric space heaters HELPS to minimize this moisture and fans directed at the windshield also help, but it is tough to remove most of the interior moisture during the Winter.
It helps if you put towels at the base of the windshield to absorb the moisture so that it does not damage your dashboard.