As more people go to full-time RVing, interest in four-season RVs has increased. Even seasonal RVers may have an interest in a four-season RV if they head north or west to see relatives or enjoy snow around the December-January holidays, or if they stay in areas with extreme heat.
There are no standards for four-season RVs, and no legal definition, but common sense dictates certain inclusions. Here are some considerations.
Let’s get a common misconception out of the way.
Many folks, especially first-time RV buyers, think an RV built to “Canadian Standards” is better equipped to handle winters. Some people even buy an RV based on that assumption.
Fact: Canadian Standards and winter-readiness have nothing to do with each other. Canadian Standards, or CSA, are a set of electrical and mechanical-systems standards that some manufacturers voluntarily adhere to. By and large, an RV built to Canadian Standards is built to the same weatherproofing levels as other RVs.
In the broadest sense, a four-seasons RV is a camper that can protect its occupants and equipment from the harshest seasonal effects: from extreme heat in summer and from harsh cold in winter. Four-season RVs tend to be more expensive—and heavier. Many are bigger models.
Beware descriptions that lack specifics. If a maker says a camper is “certified” four seasons, how so? Who certifies that it is? What is required for this “certification”? If a sales person says the RV is winterized, what does that mean? He may mean merely that there’s antifreeze in the water system to allow for winter storage—meaningless in the four-seasons livability sense. It’s your money. If it’s “Alaska Ready,” what does that really mean? Demand specifics.
In practical terms, here are characteristics a four-seasons RV would have, whether a motorhome, travel trailer or fifth wheel:
Better insulation results in two things: Heating and cooling with lower energy requirements, and more comfort in extreme weather.
The higher the R-value, the better, but finding a dealer who can tell you an RV’s R-value isn’t easy. Most RVs have walls with fiberglass batt insulation rated between R-6 and R-9. A Four-season RV ideally would have walls rated R-11 or higher.
More important are floor and ceiling R-values, probably via fiberglass bolstered by foam. In floors, look for R-21 or more, with values up to about R-36. Slide-out floors should be about R-15.
Ceilings are likely at least R-18, ranging into the upper R-30s.
Find out about construction. Foil radiant barriers do little good without an air space between them and the insulation. Also make sure insulation is adequate on surfaces that meet storage areas. Poorly insulated adjacent walls will transfer cold.
Sad to say, but take notes and try to verify a salesman’s claims. It’s easy to say “high R-value.” That’s an opinion, not a specification. How high? Consult product literature, although it often is just as vague, or call the manufacturer’s customer service line.
RVs have gaps—around windows, vents, exterior doors and wires, and in corners. Wires inside cabinets and coming in from storage areas don’t fill the holes that provide passage. Look to see if the holes are filled with insulation. If they’re not, the RV will leak a lot of energy.
Windows present a problem that’s tough to solve. Glass, at a typical R-1 per pane, just doesn’t block temperature transfer as well as an insulated wall. Double panes will do a bit better with the space between panes. The best attribute of double-pane windows is that they reduce or prevent interior-surface window condensation.
Low-emissivity glass, which reflects heat toward the warmer side of the window, helps in winter and summer. Insulated curtains help a bit, but the best thing is probably to cover windows with reflective foil during extreme weather to reflect cold temps out and warm temps in. It’s a DIY job involving Velcro and reflective foil. The downside: Your RV will be darker.
A heater needs to be at least 30,000 BTUs; bigger spaces will need even more. An undersized heater on a thermostat will run non-stop if the weather is cold enough. You may need to supplement with a propane fireplace or heater. The downside of the propane is higher humidity levels, so you may want to add a dehumidifier.
Pex plumbing lines are somewhat flexible if the fresh water inside them freezes, but the key is keeping them from freezing in the first place.
A heated, insulated enclosure beneath the rig keeps water and waste lines, tanks and dump lines from freezing. At the very least, lines should be sheathed in foam insulation.
Roof vents, like windows, are a major escape route for cooled air in summer and heated air in winter, even if the vents are closed. First, think carefully about how many vents you really need. The more you have, the less your RV—in any price range—will be sealed against energy loss. (The catch: More roof vent fans will help cool without air-conditioning in summer, using far less power than an air-conditioning unit.)
Make sure gaps around vents are filled with insulation or sealant. Insulating the vent openings themselves is an easy DIY job. All you need is a vent insulator that fits into the standard 14-inch roof vent opening. These pillow-like insulators typically have heat-reflective top and bottom surfaces. For about $10, it’s one of the most cost-effective insulating steps you can take.
Here are some 4-season RVs to give you an idea of what’s available. As you read these sites, you’ll notice that even some home pages and product brochures use ambiguous, non-specific descriptions of insulation.