You ask how or why electric mobile? There are a number of reasons why going mobile makes sense, especially if you rent. You need no permits or special permissions. You just park it in your yard and use it. You can take it with you on vacations or just for a Saturday down by the lake, you can even enter it in a parade. But why electric? Electric is no longer the inefficient dark horse of the energy world that it once was. It can be generated cleanly by wind or solar and is cheaper, cleaner, and easier to use than gas or oil. Although any purist will tell you a wood-burning sauna is the real deal, in some places wood is not so easy-—firewood may be hard to come by and to difficult store, and your neighbors may too close for comfort or offended by the occasional whiff of smoke. Since I’ve eliminated gas burners from my repertoire (for reasons I won’t go into here) an electric mobile sauna is the next best thing. All you need is a place to plug it in.
When clients ask me to create a sauna they often push me to do things I might have never considered doing. I’ve been requested to make saunas in spaces I thought were too tiny, on trailers, deep in the woods next to a pond, or to convert a cheap shed or laundry room. The most recent project to leave the shop is an electric mobile sauna. The owner has a Tesla electric car so an electric sauna just seemed to make sense. She also wanted the benches to flip up so it could be a mobile hot-yoga studio. The colors were more of an emotional choice: I painted it Sea Reflections blue like the ocean, where she likes to swim all year, with a Bonfire Red door to beckon her into the warmth of its interior, and Vanilla Ice Cream trim because, well, who doesn’t like ice cream, especially after a sauna?
The how, is simple: an 8 KW heater with a standard RV type hook up and a fifty-foot very-heavy extension cord that connects to standard car charging port (or special outdoor outlet). This will also work in many campgrounds with RV hook-ups. In a pinch, it can also be run off an 8500-watt generator.
This sauna also has a solar powered low-voltage lighting system, just so there can always be light and because low voltage systems are safer and more versatile than 120 volt lighting. I’ve been using these in some mobile wood burners and freestanding units. The neat little solar panel is a conversation starter; people are suddenly aware that the unit is more than a fancy tool shed trailer. When I tell them it’s an electric sauna, the little 25 watt solar panel gets a second glance.
What I envision next (but probably won’t consider doing unless a client pushes me) is a fully solar electric sauna. It would have to use Tesla’s 270-pound Powerwall home battery, which has an 8kw output capacity. I imagine the entire sauna roof would a have to be a solar panel but I haven’t done the engineering on this. This would not be cheap, but if there is someone out there who wants to be the first…. give me a call…
I just completed this bright blue, yellow and white gem of a sauna situated on a red deck. The color was the client’s choice; he wanted something that would brighten things up and be in stark contrast with usual suspects of taupe, dull brown, and moldy blues that afflict his neighborhood and so many other American housing developments. Why are builders so afraid of color?
The use of bright color in homes is often associated with places like seaside Baltic towns and Reykjavíc, Iceland—and for good reason. In the deep of winter these places are plunged into darkness as the sun hovers near the horizon or barely makes an appearance at all. Battling the winter blues should make the use of bright colors almost mandatory. Of course these places all have saunas too (or in the case of Reykjavíc, massive public hot springs), another way to survive the depth of winter. I also learned, when I was an artist-in-residence in Nova Scotia, that fishermen traditionally used bright colors in their houses simply because it’s left-over boat paint. Boats are painted brightly so they can be uniquely identified at sea, so, in a way, the colors express something unique about the individuals who live in there. Now, of course, the brightly colored fishing village is almost a tourist mandate.
Looking back on recent sauna projects, I see a shifting trend in color choices made by my clients. From authentic dark brown Viking tar, to blue-grey, then, brighter reds and blues and greens, and now, this latest color feast. There is also a trend in design to use more bright colors such as on the running shoes I saw in the gym yesterday that were an eye-popping florescent orange. I have been following the designer Ingrid Fetell Lee who writes about creating joy with color in her book The Aesthetics of Joy. She is persuasive about using more color for the simple reason that it creates joy. Although I teach color theory, I have a tendency to stick to blacks, grays and low intensity colors in my art, a trend that I have been to trying evolve out of. Perhaps I can take some cues from my clients and take some color risks in my own work. This latest sauna project actually makes me think of a late Mondrian painting such as Broadway Boogie Woogie in which he reduced his palette to the three primary colors and sought to use color as the basis for expression.
In this latest sauna project my interest in sauna and art actually converged. The warm interior heats your body and the colorful exterior warms your spirit. Thanks, Karl!
When the client for my latest mobile sauna project contacted me, he told me he needed something that would look and feel like a sauna from back home in Finland. He wanted it to be wood-fired and to get really hot. He wanted the clean lines and rustic charm of Finnish design and even requested a traditional pine tar finish like what the Vikings used on their boats. As small as it was to be, it was to have the standard two rooms- the sauna room and a dressing room. He also wanted to use the latest solar technology to light it with a soft glow.
But, working for an American company, where he might get moved from time to time, he wanted it to be un-tethered to his house, to be portable so he could always bring it with him, like a cherished possession.
I enjoy challenges–in fact, I thrive on them. One of the advantages of having my own company is that I get to decide how much to put into each project and which projects to really focus on. On some projects, like this one, I get to expand my repertoire. The goal, as always, was to bring my client’s dreams into reality. The result: a mobile sauna on a 81 by 120 inch trailer, under 3000 pounds, with two rooms, solar powered lighting, custom wood stove, northern white cedar interior, and pine tar exterior finish, did just that. I created a little oasis— a reminder of Finland—to park in his back yard, a dream come true.
Saunas are like that. When you have your own, it is a dream come true, a special place to escape into, to relax and unwind. It is tied to old traditions but for many, it is a new experience and can be life-changing. As designer and builder I get to be the midwife for people’s dreams and help them usher in a new way of living or rekindle a past love. As we turn the page to a new year and think about resolutions, what dreams do you want to come true?
mobile sauna by rob licht Custom SaunasSolar powered lights on mobile sauna by Rob Licht Custom Saunas
I get a lot of questions regarding sauna insulating details and thought I’d shed some light on a few issues. A caveat before I start: heat transfer science gets pretty complicated and I am grossly simplifying things here. I’m not an engineer but I rely on experience and am constantly probing and measuring my own saunas to see what works. A building inspector may want an engineer’s input, but just make sure the engineer understands what happens in a sauna.
If you are building an electric sauna, either in your house or as a stand-alone building, you’ll naturally want to insulate it for efficiency. Normally builders (and building inspectors) think of R-value (printed on every insulation product label) as the golden metric, and the R- values of a wall assembly are typically added up to get a number that either complies with code or satisfies a self imposed trade-off between cost, efficiency and practicality. R Value is the resistance to heat transfer but measures conduction and convection, not radiation, which is not much of a factor at lower temperature differentials. R values are calculated with normal living spaces and long term heat retention in mind, which in a typical home is calculated using an average temperature differential of 24°C (between heated and outside space). Since R= Delta T/ QA , (where QA is the ability of the material to transfer heat) and in a hot sauna Delta T might be 100°C, the use of labeled R factors is totally skewed!
The second factor is time. Heat loss is measured in BTU/ hr. With the sauna only on for few hours a week (bravo if it’s more!) your heat loss will be minimal and hopefully, in the cold months, will contribute to heating the house. So, in terms of cost vs. efficiency, a lot of insulation may be over kill.
At the higher temps of the sauna, the radiant effect of heat is more of a factor and the use of a radiant foil barrier comes into play. The heat you feel radiating from a wood stove is the long wave radiation. This radiation can move through common building materials but foil stops it dead in it’s tracks. Anyone who has nestled under an emergency blanket or protected himself from the fiery of a blast furnace, like when I pour bronze, understands the effectiveness of foil to bounce radiation back towards the heat source. But if the heat source contacts the foil layer, the aluminum superbly conducts the heat, defeating the purpose. So, when building a sauna, it is the radiant foil layer, with an air gap (on the hot side) that is crucial to holding the heat in. This should be backed by as much standard insulation as is practical, but don’t worry about attaining super R – value. The exception being if the wall is an outside wall of the house and a part of the building envelope- then, R-value must be a minimum of what the rest of the house has. I prefer Mineral wool, but in any case do not use XPS or EPS foam directly behind the foil, as they will melt at sauna temps!
Vapor control in an interior sauna is really important especially in modern tight houses, which tend to trap moisture, both for the damage vapor can cause that you can see, such as peeling paint, but more for the damage you won’t see, like moisture condensing in a wall cavity. Radiant foil barrier, when carefully taped at the seams, is also a perfect vapor barrier. When I build interior saunas I think about all of that moisture and imagine where it can get to and wreak havoc. I then seal off those spaces but provide a vented path for it to escape. Some enthusiastic löyly action will turn ladles of water into steam which fills the sauna but then escapes into the house— like when you forget a kettle on the stove and all your windows fog up. The best thing is to build your sauna next to a shower area and then vent that area with a decent bath fan to the outside or via the household HRV system. The sauna should then have an air intake under the heater as per manufacturer’s instructions and via a gap under the door so sauna gets a healthy exchange of fresh air. Never connect the sauna directly to a mechanical ventilation system.
With careful planning of layout, insulation, ventilation moisture control, and a heater that makes good löyly, your indoor electric sauna can feel like a wood burner on a pond’s edge but also be an integral part of your efficient home. (Read more about Sauna foam and best sauna building materials at Sauna Insulation, Revisited)
Sauna is all about perfection. Not over-the-top polished perfection, but a perfect way of being: simple, pure, functional; perfect living. Harmonious. After all, you enter the sauna naked, our perfectly imperfect bodies exposed but hidden in the dim light. You sweat out the toxins of life and leave with a clean aura. Like the Japanese concept of Wabi-Sabi, the sauna encourages acceptance of the imperfect as natural and beautiful.
When I work on my saunas I am constantly aware of this. Too much perfection will ruin the relaxed atmosphere; too many crisp details will hold tension in the materials. I relax when I work, become one with my materials and try to imbue the building with a human inexactness.
It’s all made by hand or by nature: the pulls on the doors (hickory branches), the handle on the stove (me, wrapping stainless rod—like wrestling a snake); the benches (massaged with sand paper) and the funny round window (imperfectly round like the eye of a whale). The stone facing on the wall around the stove was pulled from a hundred-and-fifty year old barn foundation and carefully split with whacks from the hammer my great grandfather used to carve head-stones. The dressing room floor: reclaimed fir, every bit as tough as the day the trees were felled. I use some new materials but never looking like I just pulled them off the shelf in some big box store.
I’ve touched it all many times—each board, each stone, each piece of metal. I carry slivers of each project in my hands for weeks—a constant reminder of the work I do. I think of our physical world built by hands. Every brick in every building handled, touched and in the memory of some callus; everything we think of as solid and real created by someone’s toil. Even the rocks that mark the hedgerow at the back of the sauna were placed by hand almost two centuries ago; the sweat of that farmer’s labor infused with this thick clay soil.
This last project was nearly perfect—which is as close to perfect as I want it to be. Great client, perfect site, easy access, and nice new pond with a beautiful dock and deck. Ok, I did order the wrong color roof but the multiple drives back and forth to Mid Lakes Metal, down the spine of the ridge between the lakes was perfect. With my windows wide open, I could taste the salt of the earth and was reminded of why I call this place home.
I’m excited about my latest project: a woodburning mobile sauna.
Unlike all of my other projects, which I design and build to meet the needs of my customers, this one is for myself. Over the past five years, I have been without my own sauna. It’s a long story: basically, I sold my house (and sauna) expecting to buy another and build a new sauna, but because the lending rules changed after the housing crisis, with a bias against self-employed folks, I have been stuck in renter’s hell. So, while my customers have been basking in the warmth of my creations, I have been languishing in a sauna-less purgatory, dependent on the generosity of my clients for the too-infrequent sauna. Like the proverbial cobbler whose kids have no shoes, I have been the sauna builder without my own. For renters like myself, the mobile sauna is the perfect solution.
It is a 5×8 sauna built onto to a commercial utility trailer. It is lined with northern white cedar and fired by one of my custom Lämpimämpi wood stoves. It has an arched roof using laminated bent cedar supports and aluminum sheet. It feels a lot roomier inside than you would think and comfortably holds 4 people. And, yes, it meets the 2,000 pound gross vehicle weight restriction of the trailer so it doesn’t require a huge truck to haul it.
I’ll use this sauna for promotion—look for it at various venues, festivals, including the Ithaca Festival parade (again! with our first appearance of a mobile sauna back in 2014). I’ll be taking this one with me on vacation or to my favorite park or forest stop. So, if you see it, feel free to stop and ask me to show it to you. Who knows, if it is hot I might even have a few spare towels.
Looking back on recent sauna projects, I see a shifting trend in color choices made by my clients. From authentic dark brown Viking tar, to blue-grey, then, brighter reds and blues and greens, and now, this latest color feast. There is also a trend in design to use more bright colors such as on the running shoes I saw in the gym yesterday that were an eye-popping florescent orange. I have been following the designer Ingrid Fetell Lee who writes about creating joy with color in her book 
