Insulation for camper van conversions
The topic of camper insulation occupies probably everyone, who would like to stay overnight in his or her camper, in particular once the weather gets cooler.
Before we talk about what insulation in a converted camper is good for, let´s say what we did in our camper: We insulated the camper with Armaflex XG. We have summarized the differences of Armaflex ACE, XG and AF in a separate article.
Why insulating your camper is a good idea!
Sound insulation:
Even though there is a separate article on this subject, we would like to mention sound insulation at this point. Because in case of rain, hail and other noises from outside (loud campsite neighbours), an insulation is very pleasant. For camper vans this is typically Alubutyl, which is glued directly to the large, smooth surfaces of sheet metal from the inside. This results in resonance damping, i.e. vibrations and thus sound waves are no longer transmitted as freely. Armaflex has very similar properties, by the way, so it is not necessary to use both Armaflex and Alubutyl. There are also some helpful Youtube videos about this.
Thermal insulation:
Before we started our camper conversion we thought long about this, but came to the conclusion that summer thermal insulation is irrelevant. During the day, we are usually not in the camper when it is hot and sunny. When you return to the camper in the evening and it is hot inside, you can open the windows for a short time and get a complete air exchange in a short time. Since the heated mass of the camper is quite small, the heat does not accumulate as long as in a house. Your vehicle will cool down very quickly in comparison.
Cold protection:
For this purpose we have decided to get armaflex. When traveling to Sweden it gets quite fresh at night, even in summer. To keep temperature in the van high, the aim is to reduce heat loss and to keep surfaces warm. Even an auxiliary heating can only help to a limited extent if the walls are not insulated. In addition, excessive heating and lack of insulation can lead to condensation. More on this later…
Moisture protection:
In 1 sentence, we can sum it up: As long as the surface temperature is above the condensation temperature which depends on the room air temperature and the humidity, no condensation will occur and therefore no condensation.
But let´s keep it simple: In order for the insulation to work, the basic rule is:
The insulation layer must remain dry. Moisture leads to a heat exchange and thus quickly to a loss of insulation performance. Mould formation is also promoted when moisture is accumulated. Moisture can get into the insulation through an exchange of air or through diffusion. The air exchange can be prevented by means of a vapor barrier film so that the insulation space is separated airtight from the rest of the room. Diffusion can also be prevented by the vapor barrier film. This step is not necessary for materials such as Armaflex, which do not absorb any liquids.
Above aspects are all relevant for our insulation. But to really insulate successfully, the following terms should be clear:
Condensation and dew point:
Due to differences in the concentration of liquid in the air inside the camper, the so-called dew point can occur: Dew point is the temperature at which the air in the room begins to condense.
On cold surfaces the room air humidity accumulates, the saturation pressure drops and condensation occurs on the cold surface, i.e. visible droplets are formed. If these droplets form on the sheet metal behind the insulation, mold and rust can form when the liquid can no longer evaporate.
In order to prevent condensation, it is important to maintain the highest possible surface temperature inside. Without insulation, the surface temperature would be -10 degrees at an outside temperature of minus 16 degrees and an inside temperature of +20 degrees on the pure sheet metal of the vehicle. In this case, moist air inside would most likely condense (without insulation). In general, of course, the room air humidity plays a major role. This means that if you stay overnight with several people in the camper, cook, ventilate less, etc., condensation will occur more quickly.
Thermal bridges
Thermal bridges in a camper are basically all parts of the frame that you have not yet insulated or have insulated less well after you have installed the insulation. Often these are struts in the roof or wall where the insulation is much thinner but is level with the thick insulation in the wide areas. The heat loss is significantly higher at these points and the temperature difference between the surface and the air in the room is highest, so that condensation can occur here particularly quickly.
Now these places are difficult to avoid completely, because even with thick insulation certain spars protrude a little further and are difficult to insulate completely. The aim should therefore be to minimize the area of these vulnerable areas. This can be achieved, for example, by placing horizontal battens on vertical sheet metal spars, so that only small contact areas are created between the spars and battens (in contrast, a vertical placement of battens directly on the (vertical) spars would not be optimal).
Conclusion
Finally it can be said that the fewest hobby camper conversions will regularly camp in winter at minus 15 degrees (celsius). If you take a look into the community there are these winter campers, but the majority use their vehicle for vacations from April to October. An insulation for extreme weather conditions certainly does not hurt, but we decided not to go on vacation during such days. And if a Blizzard does catch us on our Italy vacation in June, we will report it!
