We are building a couple of new Rhino tiny structures. One really cool thing about building Rhinos is that there is an opportunity to make changes and improvements in the next generation. This is something that you can’t really do with custom homes. With a custom home you can rely on practice. Each new home that you work on contains pieces of information learned from previous projects. But the problem is usually different and new situations are encountered.
Because the Rhino is a manufactured product, the problem is essentially the same. This provides an excellent opportunity for evaluation and development. I really like the idea that each new series of Rhinos will go through some kind of metamorphosis. By the way, these changes don’t negate the accomplishments of previous Rhinos. Some details that we changed on the new Rhino basically replaced cool details on the original Rhino. For example, I love the metal window detail on the Zulu Queen because you can see it inside and out. It is a beautiful and artistic detail. Like many things beautiful and artistic it came with a sacrifice. It is a thermal short circuit. It gets hot and cold, and transfers that inside. I don’t really care and think it is worth it for the cool factor. But on the new Rhino we have taken the thermal envelope to a new level. So the detail changed.
The reason I wanted to blog about this topic is two fold. First, I would like all of our interested readers to see the new technical improvements. A lot of visitors to the Zulu Queen have interest and have a lot of very in-depth questions. I love how smart our visitors are. Hopefully this series of blogs will give this group some good tangible info. Second, if you think that you want to tackle a container on your own, perhaps this blog will help you understand some of the in’s and out’s we have been discovering along the way.
So lets get on with it.
We bought a new container and we changed the size. We upped it to a 24′ refurbished High Cube. (Zulu Queen is a 20′ High Cube One Tripper.) This larger size is accomplished by cutting 16 feet off of a 40′ container. 24′ is a good number because 2-24′ containers can fit on a truck.
The extra 4′ provides room for a bath without sacrificing interior space. The space inside the Queen is awesome. You get the same space in the new Rhino, but you have room for a bath. The reason we chose a refurbished container was to further our goal of using a reclaimed product. The refurbished container has more dents, but is structurally the same. Also with the refurbished containers, we get to pick a paint color. Not a lot of color selection, but we wanted something to fit in the environment, so we picked green. It turns out I really like the color. It is kind of a forest green and has a feeling (not surprisingly) which seems to contain the essence of container.
Working on this new container has taught me that not all containers are not the same. From a distance you might think they are. But differences abound. I think the outside dimension from corner to corner is exactly the same. After that it starts to diverge. This new container has a little different latching system for the rear cargo doors. And the ceiling crenelation is different from the Queen. These are minor differences but they require minor design adjustments. The dents in the container don’t affect the performance but I think they add a little attitude and accent our mission. When you look at this container as a raw thing, it has a lot of character. Artistically, I think that is cool and it reinforces our belief that we can provide a top-of-the-line structure from existing raw material, reclaimed and up-cycled. I think it would be fair to say that I am a man who likes wrinkles and scars.
The next biggest modification has to do with insulation and energy efficiency. Zulu Queen is insulated with 2″ sheets of closed cell foam, often in multiple layers. This means that this Rhino is highly insulated. However, because the walls are crenelated (they have a ribbed pattern) the sheets don’t insulate effectively in the part that pokes out beyond the framing. That allows for a little airspace where warm air can build up. As it turns out, the Queen stayed quite cool throughout the hot summer. the main reason I built the Queen this way is I built it all myself. The sheets were easy to cut and work with. The closed cell spray foam takes a lot of specialized knowledge and equipment. It is a super gross and sticky job. But when its done, the result is great.
On the new Rhino we are using closed cell spray foam insulation. Closed cell foam is approximately R6 per inch. That makes our new Rhino walls R22, floor R24, Ceiling R49. In addition to the insulation it will put the vapor barrier directly on the inside of the metal skin of the container, seal any gap, and add overall rigidity to the structure as a whole. In general it really makes me feel great about the energy performance of the envelope.
The decision to use this kind of insulation had an unintended ripple affect.
First, I changed the wall construction to a more conventional 2×4 frame. That gave me a little more space for the foam.
Second, I changed the window buck design to eliminate the thermal short circuit. What this means for the inside of the cube is deep wood window wells.