Climate Battery FAQs
Will a climate battery work for my soil / climate / application?
The short answer is: it depends. It depends on what you want to grow, what your climate is like, how well your greenhouse is insulated, and so on.
We recommend that you visit the learning section of the site and take a look at some of the Projects to get an idea if someone is doing something similar to your desired application. If you’d like, we’d be happy to speak with you to discuss your project in greater depth.
How deep will I need to dig?
We recommend a depth of at least 4’ for an adequately sized “battery.” The deeper you go, the greater the capacity of your battery. A larger climate battery gives you more of a buffer to offset a period of cloudy and/or cold weather, much like a larger cell phone battery allows you to go more time between charges.
Once again, the answer for your project depends on your climate, your desired application, and the heating needs of your structure. Schedule a call or video chat with us to discuss the needs of your particular project more in depth.
What size heater (in BTUs) will a climate battery replace?
Once again, the answer depends on a variety of factors. Our early designs that we implemented at our farm create around a 20 degree temperature differential versus the outside temperature. With the insulation level of our greenhouses (double poly covering, polycarbonate end walls), this points to an output similar to a ~60,000 to ~120,000 BTU heater for our ~3,000 square foot structures.
The type of temperature differential you can create depends on several factors:
The energy input needs of your structure - How well your greenhouse is insulated and the windiness of your location
The temperature of your climate battery - A climate battery can’t heat the structure to a temperature greater than that of the soil it’s drawing from (at least, not without a heat pump mechanism). In our structures, we set the low temperature point on our thermostats to around 20 degrees F below that of the climate battery soil temperature.
The design of your climate battery - A good design can store and extract heat more efficiently. That means you can store heat at a faster rate, reducing the need to exhaust it to the outside (to avoid damaging plants), and extract it more readily when you need it. Poor designs will still be able to extract heat from the soil, but factors such as airflow rate may prevent it from effectively heating your structure to the degree that you desire. A poorer design will also need to vent more heat rather than capture it in the soil, as it can’t store heat at the rate it’s being generated.
How many feet of tubing will I need to put in the ground?
What size risers and manifolds do I need?
Which size and type of fans work best?
All of these are complicated questions with a single answer: it depends. It depends on the size of your greenhouse, on your growing goals, on the depth of your system, and so on.
The problem lies here: climate batteries are very simple in concept, but efficient designs rely on complicated physics. Our designs are optimized to use piping in the most efficient way and minimize on the amount of piping your project will require, saving you money in the process.
It sounds “sales-pitchy,” but a good design can save you hundred or thousands of dollars by reducing the amount of tubing used. For instance, a single manifold or riser pipe can cost hundreds of dollars. It’s best to economize on piping by implementing a proven design that makes full use of the piping you do purchase.
The best way to truly answer these questions is to schedule some consultation time or consider purchasing one of our designs. We’d be happy to share what we know.
Can I retrofit a climate battery into an existing greenhouse?
The short answer is: Yes, but….
It is possible to construct inside an existing tunnel, but it will likely lead to significantly higher excavation costs due to equipment size restrictions inside the structure. There is also the option to construct the climate battery outside the tunnel to reduce the excavation cost. However, you will forego some of the climate battery benefits and the tubing expense will increase. We’d recommend speaking with an excavator and consider pursuing a custom design or scheduling some consultation time to discuss options.
How much does it cost to install a climate battery and operate it?
For the most up-to-date pricing (we recalculate pricing annually), consider checking out our Costs and ROI page. Operating costs will vary depending on the size of your structure, the number of fans running, and your usage of the structure. Explore this more in Costs and ROI.
How quickly a climate battery pay for itself versus a comparable propane heater?
We estimate from 4-9 years, depending on how it’s used and other factors including your climate. Check out Costs and ROI for a more extensive breakdown based on different usage scenarios.
How much maintenance is required with a climate battery greenhouse?
Minimal. A climate battery greenhouse has only one set of moving parts: the fans. The tubing, even portions exposed to sunlight, will take a long, long time to wear out (we guess more than a lifetime).
The fans we use generally run for years without replacement. When the fans do fail (and they will, eventually), maintenance is as simple as setting a new fan in a riser.
Will I be able to grow (name your crop) in my climate battery greenhouse?
We’ve found that in our zone 6b climate, we can create more like a zone 8b/9a climate and extend our growing season by 3 full months. Our major limiting factor is the available sunshine in the winter months in order to grow sun-loving crops and recharge the climate battery during the coldest periods.
Your results will vary based on your location, the severity of your winters, and the available sunshine (especially during winter months and the shoulder seasons). Find out more on our Grower Benefits page.
Why should I buy your kits or your consulting time when there are free designs on the internet?
One word: experience. We’ve had quite a lot of experience with these systems at our own farm, have studied them in partnership with a local university, and know what works and what doesn’t. This is a huge investment that is very hard to retrofit or modify afterwards, so it’s best to get it right from the design phase. Make no mistake: most designs you’ll find work to some degree. However, we imagine you may want a design that provides the quickest return on a significant investment. We’ve focused our designs on balancing three important ideals:
Using an Economy of Tubing - No more or less tubing than what is needed to save up-front and effectively interface with the soil.
Efficient and Effective Air Movement - Choosing the right fans to move air at a speed that facilitates the greatest heat transfer for the lowest energy cost
Ease of Installation - Installing a climate battery is time-consuming and therefore expensive. The best designs should also be as straightforward as possible to install.