Hexayurt project/Cooling: Difference between revisions

We are currently working closely with Andy Buxton and his SleepBreeze personal cooler. Unfortunately we can't tell you very much about their personal cooling system at this point because it has not launched yet, but if you check that page you can get more of the picture. We can reveal a few key features:

• Aimed at cooling the person, not the entire Hexayurt.
• Low energy consumption, battery powered.
• Simple enough that, in volume production, the price would fall into our general price range.

It's important to understand that the Hexayurt project is a mix of proprietary and open systems. Specific functions, like solar power generation, require technologies with extremely expensive development costs, of a kind which open source projects can't fund. But the fruits of those developments are what we call COTS (common, off the shelf) technologies. The SleepBreeze system is a very good technology in a COTS area: you could substitute a fan, but it would not work as well.

Andy is also consulting with us on more general cooling and thermal issues, like where to position vents and how many we would need, and what kinds of interior temperature ranges we could expect to see in various conditions.

Thermal mass

The Hexayurt has a low thermal mass but has good insulation. With no air conditioning it will heat up when the sun is out. The simplest way to improve the thermal mass of the Hexayurt is to use the thermal mass of the ground under it. During the night maximise the exposed area of ground. Roll up floor coverings, open all the vents. Sleep on camp beds raised off the ground so the cold air can circulate below the bed. Wrap the floor coverings round you so they keep you warm but not the floor. Get the ground as cold as you can. As soon as the outside air temperature rises above the ground temperature (probably soon after dawn) close the vents and put back the floor coverings. In some cases the simplest way of doing this may be to move the entire Hexayurt at dawn and put it down on a nice cold bit of ground.

You now have some nice cold ground to sit on when the Hexayurt seems hot; just pull back the floor covering and sit down.As the Hexayurt is so well insulated any het in the yurt will stay inside so be wary of operating any machinery in the Hexayurt during the day. Any heat given off will serve to heta the unit. Any computers should be laptops, not towers. Any fridge should be set up so it's heat rejection (the pipe coil on the back) is to outside the yurt.