I already knew how effective my gazebo was at collecting heat in winter, even without insulation, bit the insulation aspect with radiant barrier is still being installed as I write this, the main goal for this entry is the second generation of heat storage in the structure.
The first generation was using used antifreeze in a barrel with sodium bicarbonate buffering and and a Zinc Anode rod. It worked, I just need more capacity.
Therefore I am using 5 gallon containers, with the sunward sides painted black. Mixed results on the paint type as some is flaking off.
The solution discussed in the first entry is to be an approximately 30 percent solution by weight (or mass- whichever is your preference)
With 1 kilo of water being one liter, that makes for a gallon of water to be about 8pounds and a few ounces. So accepting that margin of error of just calling a gallon 8 pounds to simplify calculations: This means for a total weight of 24 pounds of water (3 gallons) in a 5 gallon container with 9 pounds of Calcium Chloride per container.
this is less than a saturated solution, but yet enough to be able to remain liquid to minus 30 F. If I were to be using such heat storage inside a “regular” heated structure that was not expected to get below 60 degrees F, I would add significantly more calcium Chloride to achieve a solution of Calcium Chloride hexahydrate which has much more heat capacity than the saturated solution, but it becomes pretty much a solid at colder temps and you need to be in that phase change region to exploit that characteristic for maximum benefit.
This is something to consider if you have south facing patio doors that are not “Low E” glass.
Low E glass is to the left
As you can see in the image the degree of reflection in the window at left has, and it has a notable gray tint when beside regular glass, the regular glass is peeking out on the right, and it is easy to spot the lower degree of reflectivity because you can see what is behind it quite clearly.
If you are going passive solar, Low E glass will not help you. While it is okay for north facing “fenestrations”, it is by design- intended to reflect the light wavelengths that could contribute to heat gain inside of structures. This is also a reason why plants fail to thrive with Low E glass in front of them.
Low E Glass has it’s uses, but passive solar designs usually intended to collect and capture heat- not reflect it away. It is this part of energy codes which works against the use of passive solar designs.