FAQS

General Questions

  • Ceres designs highly efficient grow environments, leading to higher yields, lower operating costs, and better quality plants
  • Ceres uses the most durable and highest quality materials in order to allow for longevity for the life of the greenhouse
  • Ceres cares about client success, providing support from the build through operations and beyond  
  • Modular greenhouse design enables unlimited future expansion and total biosecurity
  • Offering a variety of Standard Kits with customizable solutions 
  • Devoted to ongoing innovation with the intention of providing the most energy efficient solutions out there
  • Data Monitoring and Grow Optimization services for the most productive grow environments

This varies by your climate and your desired indoor growing temperatures. (An energy-efficient greenhouse has a much greater payoff if you need a warm, year-round growing environment and / or have very harsh climate). We can provide an energy analysis to calculate your energy savings, or provide more information on energy savings if you send us an email with your location and growing goals.

Check out our energy calculator for a general idea on potential energy savings

Your options for building a greenhouse depend on, the size and complexity of the project, and whether you doing the work yourself or hiring it out. Generally, your options are:

Yes. We offer virtual site visits for free. In-person site visits are offered within driving distance of Ceres Offices (Boulder/Denver area) for US$125/hr. If you are in that area, we would be happy to take you for a tour to see in person how an energy-efficient commercial greenhouse looks and operates. Please contact us to schedule a tour.

A year-round solar greenhouse needs access to light particularly in the winter months. Areas that allow sufficient year-round light, with minimal shading in the winter are best. More of our recommendations are given in our blogs on the topic:

A sealed greenhouse will work in any climate. This is the best option, as it allows for precise control over the environment and all systems involved. This option is more expensive, so it might not be the best option depending on what you plan on growing, and what your goals are. 

We also offer vented greenhouses. A vented greenhouse will work for some of the year, but the exact time period will depend on your specific location, what you plan to grow, and what systems you chose to incorporate.

Ceres energy-efficient greenhouses range in cost from $50 to over $200 per sq. ft. We provide custom quotes for our greenhouses because every project is slightly different. Several factors influence cost, including:

  • Size. Larger greenhouses have a lower cost per sq. ft.
  • Whether pursuing a custom design
  • Whether you need a building permit (requires stamped structurally engineered plans, which we can include)
  • The growing and climate control systems you are adding

Because each greenhouse is slightly different, we work with you to find the best, most cost-effective method of building for your needs. Please contact us for a free quote.

There are two options for an off-grid greenhouse:

  • Design a passive solar greenhouse. This is a structure that does not use electricity, and is inherently off-grid. Instead of electrical fans, a passive solar greenhouse uses passive vents and thermal storage methods. We work with people on designing passive solar greenhouses, but most of our clients add electricity to the greenhouse for greater climate control. Much more information on passive solar greenhouse design is in our book, The Year-Round Solar Greenhouse, and you can get in touch with us if this your preferred design. While this may work well for Residential greenhouses, it may be harder to run a commercial greenhouse in this fashion.
  • Our greenhouses can be off the grid by using PV panels and batteries to create and store electricity for later use. It is important to start with a greenhouse system that has low energy consumption to begin, to reduce the investment and maintenance of the energy creation systems, like PV panels. Propane or diesel generators are also an option to provide power to greenhouses when they need heating, cooling, or any other electrical need.When an electric grid connection is possible it is advisable to create a net-zero greenhouse by using PV panels to create electricity, feeding the grid electricity at times when it is needed (usually peak mid-day in the summer), and using that electricity itself when it is needed most by the greenhouse (during the winter and at night). This is the best combination of maximized greenhouse performance with minimal environmental impact.
  • The Sunchamber™ requires three-phase power in order to power the Ecoloop® system. While it is possible to run this system off-grid, it can be difficult to find enough storage for the collected energy. 
  • We recommend contacting us about your project, and reading more about getting started with integrating solar panels in our blog, 5 Tips for Designing a Solar-powered Greenhouse.

This varies greatly by location, and what you are trying to grow. In areas with mild winters, passive solar greenhouses can grow year-round without any back-up heating. Greenhouses in cold areas can even grow very hardy crops year-round without heating, as Eliot Coleman has proved on his farm in Maine. However, to grow a wider variety of crops, in most cold climates an energy-efficient greenhouse will require some back-up heating. This is usually turned on during a few very cold nights a year — the extreme cold snaps — when a GAHTTM system, thermal mass, or phase change material is not sufficient to keep temperatures high enough.

Our innovative geothermal HVAC Ecoloop™ System is a great option for maintaining appropriate heating, cooling, and dehumidification in a sealed greenhouse.

Residential growers typically add an electric heater for the coldest times of the year. Commercial growers typically integrate propane or electric heat. We can help you integrate a back-up heater when designing your commercial greenhouse.

There are too many variables to give an easy answer to this question. The top two are:

  • What are you trying to grow, or what indoor temperatures do you want to maintain?
  • What are you typical outdoor temperatures in the winter?

Once we have that information, we can give you a ballpark estimate of how often heat will be required for your situation. For a more accurate estimate and cost projections, you can take advantage of our consulting services.

Finally, it is important to note that an insulated greenhouse, passive solar greenhouse design, and systems like a GAHT™ system, which take advantage of free solar energy, keep the heating requirement to a minimum. Most growers in North America use back-up heating sparingly in the winter, and rely on energy-efficient greenhouse design for most of the year.

Many solar greenhouse designers recommend using a roof angle that is perpendicular to the angle of the sun in the winter. While this does indeed maximize light transmission in the winter, the effect of a lower angle is not severe. We explain this relationship much further in our blog, Choosing the Best Roof Angle for your Greenhouse. Furthermore, there are a few logistical challenges to creating very steep pitch — you cannot use glass view windows on the south; it can reduce head room or create a awkwardly tall greenhouse. Due to these pros and cons, most of our residential growers are built with a shed-style roof. If you have a need for a steeply pitched roof, just ask us about our custom greenhouse design services.

The ceiling of a Ceres greenhouse, whether single slope or offset gable design, consists of trusses that run north/south and purlins that connect the trusses east/west for stability. Truss spacing and purlin layout can vary depending on building type (single slope or gable) and wind, snow, and seismic loads. A track is then installed on the roof trusses or purlins, then polycarbonate, acrylic, or ETFE, and then a top track. The east, west, and north edges of the glazed portion of the roof then are covered with paint matched flashing.

We offer a local greenhouse tour in Boulder, CO the first weekend of every month. You can find more information about our tour here.

Yes, we can help you determine the best size for your greenhouse based on your growing goals and how you hope to use the space.

GAHT® System / Climate Battery Questions

“Geothermal” is a broad term meaning heat from the earth. The term applies to many systems, including heat pumps and power plants using hot steam from the earth. GAHT® systems are geothermal too: they use the ‘low-grade’ heat provided by the shallow earth. But, a GAHT® system is NOT the same as a geothermal heat pump, a system commonly used to heat homes and commercial buildings. Heat pumps are more complex systems that use a refrigeration cycle. They circulate a fluid, not air, underground, and use pipes buried very deep — often hundreds of feet — underground. A GAHT® system, in contrast, simply uses a fan and pipe to transfer heat to the soil. GAHT® systems store heat in an insulated volume of soil, usually just 4′ below grade. They are much simpler, less expensive than geothermal heat pumps.

For the most part, yes. Ceres’ Ground to Air Heat Transfer (GAHT®) systems and climate batteries are both ground to air heat exchangers.  Over the years, different designers have given the system their own names based on their design.  Jerome Osentowski and Michael Thompson of the Central Rocky Mountain Permaculture Institute (CRMPI) coined the term Climate Battery. At Ceres, we altered the fan sizes and pipe configuration based on our research and call the system a GAHT® system.

Another similar concept is earth tubes, often called a ground-coupled heat exchanger. These use one-way air flow: they draw air in from outside, pump it underground and then it into the structure (home or greenhouse). A GAHT® system and Climate Battery circulate air in a closed loop: they take air from the greenhouse, pump it underground, and then exhaust it back into the greenhouse.

The average peak cooling load is about 10 times larger than the average heating load of a Ceres highly insulated greenhouse. A GAHT® system can cool between 2-10F degrees compared to outside temperatures, depending on the season. Therefore, the GAHT® system can provide supplemental cooling, but most often will need to be paired with additional cooling techniques for the hottest of days. For sealed greenhouses the GAHT® system alone cannot cool a greenhouse in the summer. 

The GAHT® system can provide complete heating in a Ceres Greenhouse in most climates, depending on your heating requirements (45-55F degrees) during the coldest parts of the winter.

The cost of a GAHT® system depends on the size of your greenhouse. Typically, residential GAHT® systems (under 1,000 sq. ft.) cost between $2,000-5,000. Larger commercial greenhouses and school greenhouses typically cost $5,000-$15,000 depending on size.

Our GAHT® plans provide detailed installation instructions for building and installing a GAHT® system. Here is an overview of the process:

  • Excavate a pit beneath the greenhouse (before greenhouse construction)
  • Build and install the underground pipe network in the excavated pit
  • Back-fill the pit. Then construct greenhouse. See our residential building plans for help
  • Install fans and wiring inside the greenhouse

For our residential greenhouses, we provide plans, materials lists and instructions for installing a GAHT® system. Armed with these tools, you can install the GAHT® system yourself or easily hire out the work to a contractor. We also provide phone support to answer any question that may come up along the way.

Yes, we can provide all materials for the GAHT® system, including underground pipes, pipe connections, fans and thermostats. A material list is included in our GAHT® plans and instructions. Some growers prefer to purchase the materials on their own; other prefer to have us order and ship them, and pay all at once. Please contact us for a personalized quote your GAHT® system.

Maximum depth for the pipes underground is 4’ deep. This is below the frost line in most climates, and the level where soil temperatures become a stable and moderate temperature year-round.

In locations where the water tables is higher than 4’, we do not recommend using a standard GAHT® system. Other heat storage methods, like phase change material can be used to make your greenhouse as energy-efficient as possible.

The pipes of a GAHT® system have small perforations so any water that collects in the pipes underground can drain out into the soil. Water plays in an important role in how GAHT® systems function. During the day, hot humid air is cooled underground. The temperature reaches the dew point and water condensates in the pipes underground. Through the energy transfer of phase changes, this further cools the air. It also helps water the soil underground, where plants roots are. Essentially, the GAHT® system takes water out of the humid greenhouse air and drops it into the soil underground where it’s useful for growth.

Water does not stagnate in the pipes underground and so mold is not a problem in GAHT® systems. In many years of testing systems in a variety of climates, we have not experienced any issues relating to mold.

Yes, GAHT® systems can function in any type of greenhouse. We recommend using an energy-efficient greenhouse, however. It is by far the most cost effective investment when creating a year-round growing environment.

Radon is a radioactive element that seeps into buildings through the soil. Since a GAHT® system circulates air directly through the soil, a common question is whether the GAHT® system adds a radon risk. In areas with high radon levels, this is a possibility and should be taken seriously. However, greenhouses are less dangerous than conventional buildings when it comes to radon. First, you are not in the greenhouse for as much time. Secondly, greenhouses have very high air exchange rates. During much of the year, air (and any radon) will be ventilated outside, and the whole structure will be flushed with fresh air in a matter of minutes. Even if the ventilation system is not on, greenhouses have many more air exchanges than a standard home, mitigating radon build-up. In our tests of GAHT® systems in the Rocky Mountains (an area with high radon levels), the concentration inside the greenhouse was found to be slightly higher than outdoors, but much lower than a dangerous level. By no means is this a comprehensive study, so if concerned, have your soils tested for radon before installing a GAHT® system.

Small GAHT® systems can be off-grid if you install a solar panel system. We do not provide integrated solar panel systems with GAHT® systems. Solar panels should be installed by a local installer in your area, or on your own if you are qualified.

A solar PV system can be a few thousand dollar investment, which greatly depends on the electric demand of your greenhouse. As an example, a 12 x 20 greenhouse normally includes 2 GAHT® fans, each 120 Watts. Along with exhaust fans, we estimate this greenhouse would have an energy usage of 1,000 kWh per year. In a sunny climate like Colorado, this could be powered by a 600 Watt solar panel system. At current prices (roughly $3.00 per installed Watt) this would cost $1,800 to the greenhouse project. Please note this is a rough estimation based on a typical greenhouse and solar PV system. For a more accurate estimate and to discuss the practicality of powering your greenhouse with solar PV, please contact us

To date we have never installed a house GAHT® system. This does not mean it is not possible. We just have not installed one. Before considering this option there are two concerns you should be aware of: 

  1. Radon 
  2. Mold

Radon can be tested. And even if there is radon, it is more significant to watch the rate at which it accumulates. In the worst case scenario, if radon is detected the GAHT® system can always be shut off. 

According to studies that were performed by the University of Minnesota on several GAHT® systems where mold was tested no elevated spores were detected. It is important to keep in mind this is one study, and they were conducted on greenhouses and not homes. 

When trying to mitigate mold in the home you could use a filtration system with a UV lamp. It is important to look at ducting system- how to get air through the system. We can help with the design of a new system, but it is harder to work with existing ones.

A GAHT® might provide some benefit for heating and cooling, but it generally won’t keep your home in the typical desired temperature range (68-72°F) for a significant portion of the year.  Unless you are willing to allow a much wider temperature range, you will need other methods of heating and cooling. Another issue that may arise is building codes. Since this is a non-traditional system, you might have trouble with getting approval from your governing body.

Understanding these precautions is necessary if you decide to try this system on a house. Please consult us if you are thinking of a house GAHT®.

EcoLoop™ Geothermal/SunChamber™ System

The Ceres EcoLoop™ is a hybrid Ground-Coupled-System, commonly known as a geothermal system in the United States and a Ground-Source-Heat pump in Europe. Some of the unique advantages of the EcoLoop™ system over a conventional geothermal system are the system’s heating and cooling load capacities, redundancy, resilience, and it’s low environmental impact. Also, the Ceres EcoLoop™ is minimally invasive to the earth, as the system sits 6′ below grade (opposed to the 400′ bore holes of traditional vertical geothermal systems). 
Contact us to learn more.
Material costs for installation of the EcoLoop™ range from about $50-65/sqft, and determined based on such factors as: different climate zones, size of grow operations, etc. Payback for this system occurs at roughly one year.  Because of it’s energy efficiency rating, the EcoLoop™ system may qualify for a multitude of rebates.

The EcoLoop™ system is a two part installation, below grade and above grade. This can be completed by the same contractors or two different contractors. The below grade contractors should be International Ground Source Heat Pump Association certified installers. Above grade work can be completed by a local HVAC contractor.

Ceres is happy to connect our clients to trained professionals for installation of the EcoLoop™ system.
Contact us for more information
The EcoLoop™ is a closed loop system, whereby water is continuously circulating in the closed ground loop and through the heat pumps, in order to transfer heat between the grow-spaces, the ground, and the outside environment.

Ceres is installing the EcoLoop™ in only Ceres Greenhouses through the end of 2020.  The EcoLoop™ has been optimized for high performance and efficiency using specific controls, operating parameters, and smart responses to changing conditions. 

Yes. The EcoLoop™ system can be run using renewable sources of electricity. Additionally, the EcoLoop™ design overall reduces the peak demand load compared to other HVAC systems, helping to reduce the overall size of the energy generation system.

There are pretty stark differences between both systems, making it hard to compare.  The GAHT® system is a lower tech air-to-ground heat exchanger, which can’t deliver specific temperatures but does aid with both heating and cooling, reducing overall operational costs.  The EcoLoop™ is a more powerful mechanical HVAC system, which cools, heats, and dehumidifies based on specific set points and controlled by Ceres’ Smart Controller. In general, the GAHT® system is best suited for a Ceres vented greenhouse, and the EcoLoop™ is optimal for a Ceres sealed greenhouse facility. 

The Sunchamber™ is a completely sealed Ceres greenhouse with the Ecoloop™ geothermal HVAC system and the Ceres SunSense controller, intended for the most energy efficient and highly controlled environment. This system is intended for high value crops that require precision climate control.

While the vegetables would love this environment. It is usually not necessary nor cost effective to employ a fully sealed greenhouse for commercial vegetable production. A vented Ceres greenhouse with smart controls can still provide precise grow conditions which is more than sufficient for commercial agriculture. 

For materials alone (building structure, EcoLoop™, lighting, controller, grow systems, etc.) we estimate $115-140/sqft. For a fully built structure (including all estimated construction costs) ready to grow we estimate $230-$270/sqft. 

Commercial Greenhouses

We provide tailored quotes for commercial greenhouses, as each structure is optimized for the climate and growing considerations. Pricing varies according to structure type — commercial greenhouse structures, DIY, or HighYield™ Greenhouse Kits – as well as your indoor growing requirements and climate.  Please contact us with some information about your project to get a quote.

Our commercial energy-efficient greenhouses are made with galvanized steel frames. Steel is the strongest framing material, and can be insulated in a variety of ways. We combine the frame with insulated metal panels, commonly used in warehouses or large industrial buildings, because of their high insulation values and ease of install.

We use triple wall, 16mm polycarbonate on most of our commercial greenhouses. In colder climates, the triple wall polycarbonate allows us to retain more heat while still allowing in more than enough sunlight. Our polycarbonate is incredibly durable and can stand up to the harshest weather.

We also offer acrylic and ETFE options if full UV is needed. Check out our blog for more glazing options

Our typical commercial greenhouse is a shed-style roof with a single slope. If this does not fit your site, or in cases of very large (over 5,000 sq. ft.) commercial greenhouses, we can potentially investigate other building styles, however our passive solar design does work best for optimal natural light intake. In any case, we work with you to create a custom structure that meets your needs, site and budget.

Our HighYield® Greenhouse Kits use two building depths – 23’ and 30’ – and can be as long as needed. Our custom commercial steel greenhouses are more flexible in sizing and layout, and are typically designed when building codes or other criteria dictate. We have in-house drafters who can draw  custom building based on your design needs.

We custom engineer each structure according to your site’s snow and wind loads. This streamlines the building permit process, which we can also help with. We have designed greenhouses with snow loads of up to 85 lbs/square foot, and with wind loads of up to 190 mph.

The time it takes to recoup the investment of a greenhouse depends on many factors including: crop grown, operational cost and market demand. It is important to conduct market research, and evaluate which crops would be most profitable in your area and in which season. Another factor to take into consideration is the grow system, and how long the grow process will take, resulting in numbers of harvests per year. The more harvests the more sellable product. 

Commercial greenhouse facilities can take anywhere from 6 to 12 months from conceptual design to operation. This process includes design, engineering, material orders, construction and commissioning. There are many project-specific variables, like site approval, building permit, facility size, local building season, headhouse buildout, custom features, etc. Not all factors are a requirement in every project and thus a project-specific timeline is determined for each client. 

Yield is primarily driven by the growing systems and climate control systems selected. It will be important to conduct research on the growing system options for the crops you are hoping to grow (which systems will enable the highest yields, etc.). Ceres provides the mechanism for year-round growing in addition to the design and implementation of the necessary climate controls for each grow operation. 

The utilization rate of a greenhouse is usually around 80% (without the headhouse for commercial veggie processing).

As an example, 12 small basil plant starts can be grown per sqft, whereas 1 full grown tomato plant can be grown in 4-8 sqft. 

We follow a strict process starting from design through to materials orders and project management in an effort to deliver the most comprehensive and predictable product. Change orders sometimes occur in this process, so we suggest putting a budget of 10%- 20% aside at the start of the project. It is important to keep in mind that each step of the process requires sign off and changes require approval. A change order can be $0, a positive number, or sometimes a negative amount.

Easy shipping anywhere in the US and Canada. If you are elsewhere please contact us for a shipping cost estimate.

You can install a HighYield® Kit yourself, or hire installation out to a local contractor. You can also opt to have a Ceres construction supervisor oversee the construction process and direct your building crew.

This depends on your level on construction experience. Assembling a HighYield® Kit requires significant construction experience, and a crew of at least 3 people. You can get a sense of the steps needed to build a HighYield® kit from our video. The following equipment and tools are required to install a HighYield® Kit:

  • Riveter
  • Hammer drill
  • Boom lift with forks and cage
  • Circular saw with metal blade
  • Corded impact driver

If you have experience with those tools, you can probably build a HighYield® Kit on your own. We still recommend hiring one of Ceres Construction Managers to assist with the process.

Because each greenhouse is slightly different – tailored for your climate and growing goals—we provide custom quotes for all our energy-efficient commercial greenhouses.

Estimated base kit pricing for a 30’x50′ modular greenhouse kit, for example, is US$42 – US$47/sqft (excluding shipping and taxes). We estimate US$100-US$130/sqft for complete vented greenhouse (stamped drawings, materials, equipment + construction). This is a great budgetary number to use when considering all of your systems, including the incorporation of those mentioned below.  

Ceres Greenhouses are modular by design. Both greenhouses and headhouses (indoor areas for plant processing, administrative work, storage, etc.) can be expanded at a later point. However, corridor-connected designs are more suitable for expansion because they won’t disrupt existing operations.  

It is advisable to let the Ceres engineers know ahead of time if you are considering expanding the greenhouses or headhouses at a later point. That way our engineers can design the best options upfront (at no or very little extra cost to the client), which will allow the client to save a lot of time and money when the time for expansion comes.

Like many commercial greenhouses, we often install gas powered heaters, dehumidifiers, and exhaust fans. Oftentimes, because of the built in efficiencies of our greenhouses and smaller heating and cooling loads that we deal with, we can design smaller systems to save our clients money during initial installation, and because the systems are needed less often, they save money over the long term.

The environmental control equipment and controllers will determine the quality of the products that are grown. The complexity of the control system needs to match the complexity and variety of climate control solutions used.

A greenhouse with a few circulation and exhaust fans plus thermostats can run for about $100. If the GAHT® system is employed, then humidity controls (humidification and dehumidification) and wet walls are used for cooling, and an automated controller with online system access and data storage is a good choice. 

In highly sophisticated greenhouses with high end climate control solutions for high value crops the most sophisticated control system might be the best choice. Every aspect of these greenhouse can be controlled from anywhere and data analysis packages are available to optimize yields and profits. These systems cost somewhere between $3 and $10/sqft. 

Whatever your climate control needs might be, we provide a whole systems design to ensure that everything is appropriately and efficiently integrated.

Both color choice and wall & roof thickness of the insulated metal panels can effect your building’s heat gain and retention. Lighter colors and thinner walls are recommended in hotter climates to minimize the heat gain. The thickness can range from 2.5”-6” (R-20 to R-48). 

In commercial projects, we don’t spec anything outside of the footprint of the facility. We suggest getting support from a well specialist for these components. Trenching and laying water lines underground is a safe way to prevent freezing; the frost depth and distance to the well will determine the economics of this.

We specifically design the greenhouses with a 2’ insulated knee wall under the south wall glazing.  We know that snow will slide off the roof during and after snowstorms, so we have insulated wall where the snow will build up instead of glazing, which would create a condensation and freezing area.

In situations where well water can be used to irrigate plants in a greenhouse, what are typical installations for water pipes, valves, frost protection, etc.?

This depends on the size of your commercial greenhouse. For more on basic greenhouse foundation types see our blog, Greenhouse Foundations. We work with engineers who can design your greenhouse foundation. However, because structural engineers are licensed by state, we oftentimes work with a structural engineer that you find in your area so that they will have be able to stamp the drawings in the state you are building in.

Whether or not the greenhouse needs a foundation depends on size, it’s location and the snow and wind loads. Small solar greenhouses do not need a foundation. They can be built on a level base (dirt or gravel) and anchored to the ground using rebar or products called earth anchors. For moderate to large residential greenhouses (over 120 sq. ft.) we recommend adding a foundation. Foundations can often be simple concrete piers. More about them and other foundation types in our blog “Greenhouse Foundations.”

We offer consulting on choosing a foundation type and recommend hiring a contractor to install the foundation.

This predominantly depends on how you want to grow. If growing with aquaponics, hydroponics, or in a commercial greenhouse with potted plants, concrete floors provide a clean surface to -efficient greenhouses do not need a floor. This is because the perimeter of the greenhouse is insulated. The soil below ground stays a warm constant temperature year-round. Normally, raised beds connect directly to the soil below ground. This is best for drainage and robust root growth. Flooring materials can be used in walkways. We recommend gravel, flagstone, or pavers. If planning to grow on tables, or with an aquaponics system, you may elect to install a concrete slab to create a level floor (this can also serve as your foundation). More information in our blog “Three types of floors for a greenhouse”.

Concrete floors are not necessary in the greenhouse. Earthen and/or gravel floors are also commonly used. However, this is mainly dependent on how you would like to grow, and which growing systems you are planning to use. When using Hydroponics and/or Aquaponics, a level, concrete slab is highly recommended. Another benefit of concrete floors is they can be properly cleaned, which is especially important if you intend to sell plants commercially.

Yes. With the purchase of a Ceres greenhouse, we design and source all climate control systems for your grow operation. This may or may not include the following:

  • Phase change material
  • Ventilation Systems: Exhaust Fans and Controls
  • Materials for our GAHT® or EcoLoop™ systems

We provide all materials for steel kits, or custom commercial greenhouses. For our residential solar greenhouses, the framing material is typically wood, and this is sourced locally, by you or a contractor. We provide DIY greenhouse plans, but do not ship wood framing materials.

Yes, we ship greenhouse materials to your site. In some cases, we may use a local distributor and have materials available for pick-up at a nearby store to allow for easier pick-up and cost savings.

Yes, Polygal polycarbonate comes with a 10-year warranty and Lexan polycarbonate comes with a 15-20 year warranty.

Residential Greenhouses

The cost of a year round greenhouse depends on a lot of things, primarily the size, how you source the materials and who builds it. To give you a general idea, some growers use recycled materials and do all the work themselves and spend as little as a few hundred dollars for a residential solar greenhouse. More commonly, growers buy new materials that will last longer, and outsource some or most of the work. A common range is to spend $15,000 to $40,000 for a durable and energy-efficient backyard greenhouse

This varies greatly by location, and what you are trying to grow. In areas with mild winters, passive solar greenhouses can grow year-round without any back-up heating. Greenhouses in cold areas can even grow very hardy crops year-round without heating. However, to grow a wider variety of crops, in most cold climates an energy-efficient greenhouse will require some back-up heating. This is usually turned on during a few very cold nights a year — the extreme cold snaps — when a GAHT® system, thermal mass, or phase change material is not sufficient to keep temperatures high enough.

Residential growers typically add an electric heater for the coldest times of the year. Commercial growers typically integrate propane or electric heat. We can help you integrate a back-up heater when designing your commercial greenhouse.

Yes! Attached greenhouses have many advantages, such as provide passive solar heating for the home. However, they require specialized materials and air exchanges for an energy-efficient structure. Depending on the project, we will sometimes team with architects and local contractors in building durable, beautiful and efficient greenhouses.

Many solar greenhouse designers recommend using a roof angle that is perpendicular to the angle of the sun in the winter. While this does indeed maximize light transmission in the winter, the effect of a lower angle is not severe. We explain this relationship much further in our blog, Choosing the Best Roof Angle for your Greenhouse. Furthermore, there are a few logistical challenges to creating very steep pitch — you cannot use glass view windows on the south; it can reduce head room or create a awkwardly tall greenhouse. Due to these pros and cons, most of our residential growers are built with a shallow angle roof. If you have a need for a steeply pitched roof, just ask us.

Yes, we work with clients all over the world. Our standard greenhouse plans, and custom designs can be applied to greenhouses in any location. We often customize the greenhouse to optimize performance for year-round growing in your climate.

The 11’x18’ BackYard base kit price is $30,880. This includes frame, panels, fixed windows, roofing system, door and our SunSense™ controller.
The price for our 18’x24’ is currently US$44,790.

Please contact us for more information.

Plans, available in several sizes up to a 12’x24′, can be purchased from our web store  for US$750 and include all you need to construct your greenhouse with our support throughout the process. We estimate US$68-US$70 / sqft for materials. While building and labor costs vary greatly based on your geographic location, should you choose to hand this project off to a local builder, we estimate US$130- US$150 for all materials (both greenhouse and GAHT®) and labor. 

This depends on what type of systems you want to use for growing, and controlling the greenhouse environment. Typically, our residential greenhouse growers install electricity in the greenhouse to run fans and lights if necessary. These have a very small power draw but do require electrical hook-up. The simplest option is to wire the greenhouse to the home. Another option (though usually more expensive) is to install a solar panel system to run the electrical components.

You can also build a completely passive solar greenhouse – one that does not use any electrical components. For this we recommend using passive solar vent openers to provide automated ventilation. There are several pros and cons to building a passive solar greenhouse vs. an active one. Much more information on solar panel systems and passive solar greenhouse is in our book, The Year-Round Solar Greenhouse as well as “Integrating Solar Panels into the Greenhouse.”

There are a few different ways to handle watering in a residential greenhouse. These depend on the size and water requirement of the structure (climate dependent). They vary from a water hook-up (spigot) to using self-watering growing beds. For more see “Solar Greenhouse Basics: Watering Systems.”

With little sunlight and temperatures dropping below freezing, our residential growers most often have to rely on a supplemental heating source; such as propane, natural gas or electric heating sources.

How residential growers fare is also largely dependent on what the residents are growing. For example, for our residents growing leafy greens and more frost tolerant crops in Boulder, CO and Wisconsin the GAHT® is able to maintain temperatures from as low as 27F degrees to low 40s. When it comes to growing figs or tomatoes, on the other hand, one might try keeping an electric heater running in the evenings, and mornings when there is little sun.

Vesta™ Kit House

Yes. A forklift or telescopic handler is required for raising some of the large columns and placing the rafter beams. All of the main framing is bolted together (bolts supplied) and the lighter gauge framing is connected with bolts/tek screws.

Yes, expansion is possible. Because we are not specifically designing for expansion, design fees may apply.

Yes. The tightness of the building and high insulation value works great in both hot and cold climates. 

The Vesta can be built by the anyone with some construction experience or a local general contractor. Ceres is always there to provide guidance and support during the build process. 

Ceres offers several recommended floor plans at no cost. Owners can design their own floor plans or work with an architect/design-build firm to design their own layouts as well.

The client or contractor. This is not supplied by Ceres. We understand where we offer value and where the customer can find the same materials elsewhere and save money on extra shipping costs. 

No. The greenhouse comes with a ventilation system, which includes exhaust fans and intake louvres. A retractable shade curtain can be installed for additional cooling or removable shade paint can be used during the hottest months. We also offer a recommended HVAC system for the house and greenhouse, so you could have cooling installed in the greenhouse as well.

Depending on your power needs, the Vesta has space for a 4 kilowatt solar system (assuming 11, 375 watt panels) on the south facing greenhouse roof. With modern appliances and mechanical systems this could be enough to make the house net zero or net positive. Ceres can offer a solar layout design and recommendation for a small fee, to be installed by a local solar contractor. 

We have space for 11 3.5×5.5ft solar panels on the south facing greenhouse roof. If this is grid tied, it may make sense to add more solar panels on the roof of the house as well.  While the orientation of the roof is not ideal, it is advantageous in certain locations to increase solar capacity.

Yes. The entire roof of the house portion is steel and slopes to the north approximately 1,000sqft. A rainwater collection system can be connected to the north side of the roof. Please note that rainwater collection can be illegal in certain locations, so we advise you to call your local authorities for regulations where you live.

Currently we have not sought out any certifications, but we may in the future. If that is something you would like to explore for your own home, we would be happy to support you in the process. 

At this point we are anticipating 2-3 months for delivery. While some of this time is for design and permitting, clients can be working on foundation, etc, once plans are complete.

If radon is detected a mitigation system can be installed under the slab before construction. This is dealt with by the homeowner or contractor, and does not fall under the responsibility of Ceres. 

In the greenhouse, venting is the first step and an optional dehumidifier will help with dehumidification in the winter months. The greenhouse heater will also help with greenhouse humidification loads.

Environmental Controls

At Ceres we focus on building the most energy-efficient commercial greenhouses as possible. Our primary heating and cooling method stores the greenhouses’ heat (free thermal energy) in the walls and in the earth below the greenhouse. We are well-known for our GAHT® system, a Ceres designed ground to air heat exchanger, which we have designed for many years all over the world. We also use phase change material. For our sealed greenhouses we offer our Ceres designed EcoLoop™ System, which uses earth’s steady temperature to heat, cool, and dehumidify inside the greenhouse. Finally, by using passive solar greenhouse design principles we minimize the heating / cooling load as much as possible, making our commercial greenhouses much easier to regulate and much more cost-effective versus traditional greenhouses. We also integrate back-up heating, cooling and ventilation systems as needed.

Growing systems are customized according to growers’ needs, and specified after a consultation. Ceres will design and source the grow system that is required for each particular growers needs.

Ceres will also design and integrate for:

  • Light deprivation systems (if needed)
  • Supplemental lighting, automated shade systems
  • Climate control and HVAC equipment
  • Monitoring systems
  • Water Reclamation and Filtering systems

Like many commercial greenhouses, we often install gas powered heaters, dehumidifiers, and exhaust fans. Oftentimes, because of the built in efficiencies of our greenhouses and smaller heating and cooling loads that we deal with, we can design smaller systems to save our clients money during initial installation, and because the systems are needed less often, they save money over the long term.

The environmental control equipment and controllers will determine the quality of the products that are grown. The complexity of the control system needs to match the complexity and variety of climate control solutions used.

A greenhouse with a few circulation and exhaust fans plus thermostats can run for about $100. If the GAHT® system is employed, then humidity controls (humidification and dehumidification) and wet walls are used for cooling, and an automated controller with online system access and data storage is a good choice. 

In highly sophisticated greenhouses with high end climate control solutions for high value crops the most sophisticated control system might be the best choice. Every aspect of these greenhouse can be controlled from anywhere and data analysis packages are available to optimize yields and profits. These systems cost somewhere between $3 and $10/sqft. 

Whatever your climate control needs might be, we provide a whole systems design to ensure that everything is appropriately and efficiently integrated.

Our greenhouses utilize passive solar design, called ‘solar greenhouses’ for short. Passive solar greenhouses are designed to maximize heating from the sun, to create an efficient self-sustaining year-round growing environment. While they can be powered by a solar PV (solar panels), Standard models do not include solar panels (photovoltaic systems). We can help you integrate solar panels into your design, depending on the project and your solar requirements, to make the greenhouse completely self-powered, net-zero energy or off-grid. Depending on the project, we can offer a solar design based on your power needs and how much power you want to offset.  These designs can then be taken to a local solar installer for quoting and installation.

Controller

Yes. We offer a few different options for a vented greenhouse. Please contact us for more information.

At this time we are not offering the Ceres Controller for non-Ceres facilities.

Predictive controllers look at the weather forecast and will select the most efficient mode of operation considering the weather to come. For example: After several days of intense sunshine the weather is expected to cool down significantly and more clouds are expected. A predictive controller will let the ground sourced water temperature creep up during the warm/sunny phase so that the stored heat in the ground can be used to heat the greenhouse.

Yes. Our highest level SunSense™ Controller (designed for our SunChamber™)  comes with a set of automated needle point valves and CO2 sensors in each grow room to control CO2 levels.

Yes. In greenhouse applications where supplemental CO2 is used the SunSense™ Controller comes standard with horns, strobes and signage required by regulation to warn any person in the building. In case of critical CO2 concentration, the controller will initiate automated venting until the CO2 concentration is back in the safe concentration range. 

The customer owns their data forever. However, we do require access to it for facility optimization. Data sets will not be shared with or viewed by other customers.

Data is stored on-site and on a server in our office accessible by the cloud at any time. This will protect from loss of data.

The dashboard allows the owner to set levels of access to employees, so you control who sees your data. 

The dashboard allows the owner to set levels of access to employees, so you control who can change stage settings. 

Data can be accessed via the SkySpark page on our Controls Dashboard, which links you to your facilities SkySpark Dashboard. From there, the customer can see all historical data from each sensor, equipment run times and operational modes, power consumption, etc.

The dashboard shows the details of your facility operations. This includes live sensor data, current operational modes of all of your equipment, facility power consumption, local forecast, a page for recipe development, and links to your fertigation controls (if applicable) and SkySpark dashboard. 

The dashboard’s pictures and equipment will be customized to your facility, but we do not change the overall format/layout of our dashboard. 

Ceres offers a yearly data analytics package, where the Ceres’ data team will work with you to optimize your facility operations and maximize your crop yield.

The Ceres Data Package cadence typically looks as follows: Our data team will analyze your data in preparation for a monthly meeting with your team where we will explain the trends we see and make recommendations on how to change your sequence of operations. Once agreed upon, we will make the changes and push the software to your system. This cadence is tailored to fit your team’s availability and needs. 

Our intention is to minimize operational cost and maximize crop yield. We focus on peak load avoidance, optimizing EcoLoop™ (when applicable) set point selection for the most efficient operational modes. We balance all environmental outputs to best fit your exterior climate, and the needs of specific crops. 

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