Airhead vs. Sun Mar Composting Toilets for Your Tiny House

It’s time to talk crap… Airhead or Sun Mar – who’s better?

10,000,000,000 gallons – that’s how much perfectly good drinking water is flushed down the toilet every year in the United States; literally.

Fortunately, modern technology offers us more than one way to handle our business. The folks at Dancing Rabbit Eco-village have considered almost all of them, because we want to make sure we are pooping in the most eco-groovy way possible. (Otherwise we have to hold it in…) We’ve decided that the humanure system works for best us, and most of us are content to use a DIY composting toilet that can be easily built by almost anyone for less than $50.  (If you’re interested in exploring what an ecologically sustainable tiny house lifestyle looks like, consider coming for a visit soon – and while you’re here, you can check out over 15 tiny houses all at once.)

Sun Mar vs. Airhead Comparison

Now let’s get down to business. Two of the main manufacturers of commercial composting toilets are Sun Mar and Airhead.

Which one is better?

Well, like everything else in life, it depends on which criteria you’re using to evaluate them. Different folks need different strokes, and there’s no way around that.

However, it seems to me that most of us in the tiny house movement have some principal desires in common when we are choosing features for our homes. Namely: space savings, cost savings, ease of maintenance and overall aesthetic appeal.

So, rather than evaluate each and every model of composting toilet being offered by both of these companies and taking your time to explain my rationale in excruciating detail, I’m just going to choose the one I think makes the most sense from a tiny house perspective for each brand and then compare those to each other.

Sound good? I hope so, because that’s what you’re getting.

From Sun Mar, I chose the so-called ‘Space Saver’ model.

It’s aptly named for its small footprint of 19.5” X 23”. It comes with all the bells and whistles you might expect, like an electric ventilation fan and drainage connections, and it even has a dandy little retractable stool so your tots can reach the seat.

Unfortunately, in order to maintain the privy you have to lift the entire top of the holding chamber up and back on a hinge. This means that it cannot be installed right up against a wall, which will lead to some wasted space directly behind the unit. In the process, the contents of the privy are exposed. Composting human waste doesn’t smell as bad as you might imagine, (especially if you’re separating your liquid and solid effluent, which you should be,) but still, I’d rather avoid catching a whiff if I can help it. It also costs $1695.00. Ouch.

As for Airhead, I went with the ‘Household Size’ model.

It has a compact design with a 19” X 17.5” footprint, and comes with all the connection options you might need. It has a dapper steampunk design that I think is quite attractive, and it’s designed to be installed flush against the wall. (Pun intended.) Best of all, it includes a separate tank for liquids, which can be dealt with separately. Airhead also offers a wide array of customizable options, including a solar panel to handle the electrical requirements of the unit.

It has its own downsides, as well. The smaller size means that it will need to be emptied more frequently, and it comes with a price tag of $1029. Ouch.

So, which one is better?

For my money, I’d go for the Airhead model.

It’s smaller, better looking, and it’s designed with easy maintenance in mind. Sure, you’ll have to empty it more frequently than the Sun Mar, but for a cost savings of about $700, I think I can use the exercise.

There you have it! If you’re interested in learning more about tiny house design in general, I want to invite you to spend some time with us at Dancing Rabbit Eco-village sometime soon. We have several expert builders in our community who can give you all the dirt on natural building, energy efficient materials, and lots of other things that accompany the tiny house lifestyle. If that sounds like something that might float your boat, check out all the different ways you can schedule a visit.

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Jason - December 12, 2015 Reply

We have the airhead, it works great. You need to follow the instructions, add enzymes to the coir and keep a bit of an eye on moisture in the solids tank. Do that and its amazing! You can put your nose the the tiny 12vokt fan on the vent pipe and it smells like garden soil. One thing to consider with any small scale composting toilet system is what to do when you have a crowd over for a gathering. These systems work best with a couple of people making daily deposits. Too much poop all at once and the bacteria get a bit inundated… Maybe set up a second simple humane manure system for such occasions in a makeshift outhouse. That way every one gets a pleasant experience and you won’t have to stress about an unpleasant odour un you tiny house. p.s. Also a good idea to put on some background music to blend the noises from the tiny room, a lot of your visitors will be self-conscious of that, and its good to make their tiny house experience a positive one. 🙂

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