By Gary Bunzer, Technical Editor
June 2018
Extreme Condensation
Last fall a metal pole building was constructed for my motorhome. Prior to that, the coach was housed at a storage facility that once was a lumberyard; so, it was under roof but exposed to the outside temperatures and even the elements a bit. I went into the pole building recently and was surprised to see that part of the motorhome was covered in condensation — so much so that it was dripping onto the floor. We had a big change in temperature — from below freezing for days to almost 60. I’m guessing the condensation has something to do with where the insulation is.
Should I open the motorhome windows while the coach is in storage to balance the inside-out temperatures? I definitely don’t want that condensation inside. I did see condensation dripping from the motorhome when it was at the storage facility, but I didn’t expect this when it’s parked inside. Any advice? Do I just need a big chamois to dry it off?
Mike Kay, F421999
Cincinnati, Ohio
The condensation occurs when the surface temperature of the motorhome is below the dew point of the air surrounding it. So, if a warm front brings in warm, humid air and it comes in contact with a cold coach, condensation will form on hard surfaces below the air’s dew point. I have a couple of recommendations. Since the coach is indoors, I suggest opening the lowest window at one end of the RV, just slightly, and opening a roof vent positioned farther back in the coach, if possible. That way, normal convection air can circulate through the RV.
Some RVers may leave the coach plugged in during storage and run a small space heater inside, but I cannot recommend this unless it operates only when someone is present. I recommend placing one or two H2Out Space Dryers inside the coach, one at each end. I like this type of dehumidifier, as it can be used over and over. For more information, visit www.h2out.com/space-dryers.
With the typical RV having thin insulation — and its effectiveness often reduced even further by a large expanse of windows and drastic temperature swings — it is inevitable that moisture will form somewhere. The key is to be sure the sealants are in good shape around the windows, doors, and roof components, as well as around anything attached to the RV’s exterior. Annual inspections can be reassuring. And that big chamois won’t hurt in the interim.
Scalding Moment
We have a 2016 Forest River RV. We’re happy with all aspects of it but are puzzled by the shower. While showering, we try to conserve water by turning the water on and off at the handheld showerhead. When we turn it back on, the water is scalding for about five seconds before it returns to the adjusted temperature. None of the plumbing in the rest of the motorhome is touched. Any ideas?
Andy Switzer, F474332
Gulfport, Mississippi
Here’s what probably is happening. With the shower running, both the hot and the cold faucets are open. And when you shut just the showerhead off, both faucets are still open, right? It just means the flow has stopped at that showerhead valve. With both the hot and the cold faucets open, the hot water is simply mixing and migrating back into the cold-water supply from the faucet on back and up the hose to the showerhead, thereby preheating the cold water.
The longer the flow is held up, the hotter the water gets as it warms farther back into the cold side. Then, when you turn the showerhead back on, with the cold water diminished and the hot water still there, you get that blast of hot until the flow evens out to your original settting. I’m guessing the water heater is located near the bathroom, thereby exacerbating how quickly the heated water gets into the cold lines. It’s one of what I call my “RV facts of life.”
This same phenomenon occurs with an exterior showerhead. If RVers just stop the flow at the showerhead and forget to turn off the hot and cold faucets, eventually the cold water begins to heat up.
The fix? Aim the showerhead away from you for a few seconds when you first turn the showerhead valve back on. And remember at the completion of your shower to turn both the hot and the cold faucet off completely. Annoying perhaps, but probably only a minor bother, since you are conserving water and saving gray-tank capacity.
Smaller Extinguisher
I am trying to find handheld RV fire extinguishers that are the aqueous film forming foam (AFFF) type recommended by Mac McCoy, better known as Mac the Fire Guy. He sent me to Fire Fight Products (www.firefightproducts.com), but the only handheld foam model they sell is the SS20 16-ounce aerosol-type extinguisher. Here’s what they said:
“They are $30 each or $25 for six or more, plus shipping. We suggest putting one for each person in the bedroom area, one in the kitchen/galley area, one by the door, and one up front in the cockpit. If you tow, we recommend putting one on each side of the towed vehicle.”
I’m hoping you have your own solid knowledge of RV fire extinguishers and can weigh in on the advisability of the above advice regarding relying entirely on an abundance of 16-ounce aerosol units. Or do you know another source for a handheld foam-type fire extinguisher that is less than 6 liters, the only size I can find? That seems bigger than I would want in the RV.
Pat French, F450764
Tualatin, Oregon
I, too, am a fan of Fire Fight Products and have recommended their products in the past. I have noticed other AFFF extinguishers on the internet, and some are smaller than 6 liters, but I’ve never evaluated them. A company called Lifeline sells such extinguishers in 1.0-liter, 1.75-liter, and 2.4-liter sizes: www.lifeline-fire.com/lifelineafffhandheld.aspx.
I, too, recommend an assortment of the smaller containers strategically placed throughout an RV and perhaps the towed vehicle, rather than placing my faith in a single extinguisher. In some cases, that single extinguisher may not be accessible in time. Mac has recommended at least five extinguishers in the RV, and I agree.
Send your troubleshooting questions to rvdoctor@fmca.com. The volume of correspondence may preclude personal replies. Not all responses will apply in every instance. Some situations may require a visual inspection and hands-on testing. If you choose to follow any procedures outlined in this column, first satisfy yourself that neither personal nor product safety will be jeopardized. If you feel uncomfortable about a procedure, stop and make an appointment with an RV service facility.