Our Bus and home, affectionately known as ‘Molly’ was a hotbox. More than half of her interior height is windows, and the rest of the walls and ceiling are two sheets of thin tin, with non-existent crumbling old glass insulation, sparsely clumped here and there in between. Stepping inside in the height of a record hot Australian summer was like stepping into a blast furnace. A very humid one! Before we were able to comfortably sleep in her, we needed to make some serious changes. All of these changes were not necessarily things that could be seen as progress as they were ‘behind the scenes’ kinds of jobs, and it seemed to take a long time. The extreme heat and lack of sleep due to having a wee person also slowed us down, but it was critical that we got these things in place before starting to build walls etc.
The first job was insulation. We bought a compound foam product used in ceiling installation which has one reflective side, a bit like a car windshield reflector. Although it is only 8mm thick, its insulative properties are far superior to the old glass wool and it’s much easier to work with.
Jack painstakingly drilled out every single pop rivet in the ceiling (Thank you again, my amazing husband!) and fitted cut-to-size pieces of insulation throughout the ceiling, and the same in the walls below the windows. We used some recycled polystyrene to fill the cavities which ran below the floor level of the walls. This is not recommended for use in vehicles as your main insulation, as it will crumble in time and the little ‘beads’ all fall to the bottom of your wall. However we had the poly laying around and figured we had nothing to lose by tightly stuffing it down below the main insulation.
The next job was sewing some heavy rubber-backed curtains to help combat the afternoon sun. It was a little pricey, but I bought the very best quality I could find with the most insulative qualities. Buying ready-made would have worked out MUCH more expensive so if you can sew a straight line I would highly recommend sewing your own. That way you get the exact size you need as well.
One trick to keeping out extreme heat is to hang the curtains as close to the windows as possible. After trialing a few ideas, we settled on using 5 small ‘3M’ hooks per curtain (the little clear removable ones). These worked our great and are surprisingly strong! They are invisible behind the curtain and hang very close to the glass. You can take them off completely to take advantage of the view when the weather is nice and they are super easy to pull off to wash. On the first curtain I sewed 5 buttonholes. It looked okay but was a lot of work on the heavy material. The next one I decided to sew 5 small tabs of elastic on the back instead, and this worked out fantastic! It hid the hooks all together and gave just a little bit of stretch if the wind happens to catch the curtain. I did the same with the rest of the curtains and am super happy with the results.
The third thing we did to help combat the heat was to tint the windows.
Beware. DIY window tinting can be challenging at the best of times. If you dont have a lot to spend (as we didn’t at the time) and opt for cheap chinese tint online, the challenges multiply by like a bazillion percent! The tint is so thin, it’s like sticky celophane. One puff of breeze and it all sticks together and is impossible to pull apart without tearing. Anchoring it with tape while carefully peeling the inner (clear) film is next to impossible. The window must be pre-dampened so the tape doesn’t stick very well, and if you happen to make it to the window with clean film and no nicks or fold marks, its very easy to pierce when squeegie-ing it in place.
All that aside, if you have the patience and some experience then by all means have a crack at it. If you have some spare dough I would highly recommend getting a professional to take care of it. It will be quick, clean and a higher quality product.
Of all the things we did, tinting the windows had the biggest impact by far on the inside temperature. The curtains and insulation did helped a lot, and combined it made a world of difference.
These are the major jobs we did to our bus to improve the temperature, however there is plenty more you can do to avoid melting if you don’t have air conditioning, which will really make a difference.
If possible, park your vehicle in a position where it can catch any little breeze. Even a slight one can make a huge difference. A good thing to remember is that it is always a little cooler near water.
If you have hatches or whirly-birds, make fly screen covers for the ceiling and let the hot air escape. Install mozzie screens on doors and windows so that you can take advantage of crossflow ventilation without being eaten alive. We got these magnetic flyscreen curtains from bunnings, only $9.90 per set. They fit a standard door and can easily be converted to a bus or RV doorway using velcro.
Portable fans are great and can be charged via solar panels, USB, power banks or battery and are much more energy efficient than conventional 240v ones. We bought the boys one each of these personal fan & light combos for Christmas, and they were fantastic. If you are in the market for one they are currently $16 off via this link. You’re welcome 🙂
To further keep you chilled, a cooling head buff is awesome in the hot weather. It works by evaporation and is chemical free. The advances in textile technology means that it remains up to 30% cooler than your skin temperature. Cool! They are stretchy and can be wrapped in endless ways to keep you temperature down. And they look super cute to 😉
Lastly, if you are not desperate for direct sun to charge solar panels, park up in the shade. Always check the type of trees you are under for white ant activity, or signs that they may be limb droppers ie: lots of large debris around, ‘widow makers’ hanging in trees etc.
Although extreme temps can be uncomfortable, a combination of the above ideas can make a world of difference. We were able to get baby to sleep with the help of a small 12v fan during a record 47+ degree Australian summer heatwave. Having said all that, we plan on saving up and installing reverse cycle airconditioning in our bus before next summer. With all of the work we’ve done to insulate our bus, we will only have to run it on a very low setting which will save precious power from our solar setup.
Read more about how we power our tiny home on wheels for a family of 5 entirely off grid here. (coming soon)
Until next time, safe travels!