2020 was a year that changed everything. We all had to adjust to a new way of living. Many of us found ourselves spending more time at home than ever before. For some, this meant turning to the garden. We were forced to reevaluate how we were doing things. There were questions about global supply lines and food supply in general.
Maximizing Thermal Mass and Heat Storage in a New England Greenhouse
If you were like many of us, you might have gone out to your garden and looked at it, wondering if it was producing as much as it could. This led to a lot of us to reevaluate how we were doing things.
For Mr. Allen, his garden was more than just a hobby; it was a way of life. He had built a greenhouse out of two pell room greenhouse kits on top of a raised bed about 10 years ago. Overall, he was very pleased with how it worked. Fast forward a decade to the global pandemic. He decided to try sweet potatoes in the greenhouse.
After a few months, these plants did so shockingly well that it was time to say goodbye to the old greenhouse. It was time to make one that could stand up a little better to the temperature extremes of New England. He knew that the new one would need to be designed with major considerations given to storing heat. He needed to create thermal mass.
During this time, he spent two months jackhammering solid rock to make a spot big enough to install the new greenhouse. He decided that a ground air heat transfer system was the best design approach. A ground air heat transfer system is when hundreds of feet of pipe are wound underneath the greenhouse. Hot air from the greenhouse is forced through those down into the ground.
Once the ground air heat transfer system had been installed, he built a 12 by 12 raised bed. He used gabbian baskets. The new baskets were covered inside and out with two layers of commercial-grade weed barrier. The main access to the bed would be from the sides of the bed. This maximizes the growing area because you don't have to leave areas where you would walk inside.
The entire floor was covered with hardware cloth. Then a layer of heavy ground barrier fabric, then a layer of r6 insulation, another layer of ground fabric. Lastly, he added three inches of gravel. In the widest area of the floor, he also used four-inch-thick pavers. All of these are steps taken to maximize the thermal mass. This contributes to the heat storage of the structure.
In spite of single-digit temperatures, he was able to set the structural timber that he had milled. He built a temporary work area on the lower area of his property. He could lay 20-foot beams, making cutting them to length as well as cutting the mortises and tenons much easier. The first two weeks in February were unseasonably warm. This allowed him to complete the walls and get all of the roof done. He used pallets as the material for the roof shingles.
The watering system is complete. He is now working at balancing it. He wants to supply every plant on the property with the water that it needs. He installed a wall of food-grade buckets that he picked up from the neighborhood deli. He then built a workbench, and seating area along the back wall. Of course, no ground air heat transfer system is complete without fans and control systems.
What started out as a seemingly innocent garden task turned into months of hard work and a bunch of cash being spent. If you are curious about how much of it was free and the overall cost of the greenhouse, Mr. Allen made a separate video specifically about that.
The moral of the story is, even the simplest of gardening tasks can spiral into something much more complex and costly. But for Mr. Allen, it was all worth it. He now has a greenhouse that can withstand the temperature extremes of New England. The ground air heat transfer system ensures that the plants inside get the heat they need.
Have you ever spent more for your garden than you intended to spend? It's not uncommon. So many gardeners tend to get carried away with their projects, end up spending much more than they initially intended.
Sometimes, a simple gardening project can spiral into something much more complex and costly. But for those who are dedicated, the end result is worth the cost and effort. Whether it's a greenhouse, a ground air heat transfer system, or just a simple raised bed, investing in your garden can pay off.
Invest in your garden. You might just be surprised at the results.
