Greenhouse: Pool Bubble Greenhouse, 0 by JPlunket

JPlunket wrote:
Here's the pool covered by our bubble --a simple but ingenious design that allows us to do our laps swimming against the current in the 16X10 pool every day, regardless of weather or temperature through the winter.

It's made of heavy plastic, custom-designed to fit a set of anchor points that thread down into certain points on the deck. A steel cable around the bottom "hem" holds the bubble down, and an interior plastic flap seals almost perfectly against the deck. We cover the wooden deck with heavy black construction sheeting to make the whole thing as airtight as possible. Entry is through a zippered slot --in and outs have to be quick, to keep interior air loss down.

The heated pool heats the interior of the bubble, mostly by evaporation, some radiation/convection. So, humidity is usually 100% and on most days a rainforest environment, with condensation dripping from the ceiling and running down the walls. temperature inside is easy to maintain at >45 degrees F (7 - 8 degrees C), even when it's in the teens F (say, -12.5C) , when the condensate freezes against the side walls (never the ceiling) --those are the days when we need a cup of boiling water to melt the zipper, just to get in for our 30-minute workouts.