How to Insulate a Greenhouse

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How To Insulate A Greenhouse

Insulate your Greenhouse with these Effective Methods  

Whilst a greenhouse is designed to shield crops from excess cold and heat, its functionality may be limited during extreme weather conditions, and that is where insulation comes in.

Mastering the art of insulating a greenhouse could not only help you maintain a steady agricultural output but also save you a great deal of heating/cooling costs; hence increasing the general efficiency.  

Hopefully, by the end of this, you will be in a position to implement the most convenient insulation technique and acknowledge the importance of such DIY projects.  

Factors to Consider

Before getting to the actual methods, it is imperative to understand all the underlying factors, since they dictate the type and amount of insulation you need:

  • Crops thrive in different conditions;  

There are warm-season crops, cold-season, and all-season types of crops; all which require different methods of insulation. In essence, your first course of action should be determining what kind of crops you have and which type of insulation suits them best.  

  • There are numerous greenhouse designs, all of which have diverse variations.

Though not so clear to the untrained eye, you would be amazed by how the design specifics could affect the overall greenhouse productivity. From the ventilation framework to the default temperature and the material used for construction, understanding the make-up of your greenhouse will help you understand the bigger picture; it’s the little details that matter.

  • The environment where the structure is located.

It goes without saying, every place has a different climate. For instance; The heat loss in Iceland is incomparable to the one in New Zealand. It would be pointless to have the same insulation mechanisms in such different cases. Your location should help you establish the most logical insulation method to use.

  • Cost and budget

With increased costs of fuel and electricity to generate heat and run greenhouse heaters, greenhouse insulation has proven to be more cost-effective. Even so, there are methods of insulation that are more expensive than others, as we shall see. Depending on your estimated budget, you should be able to choose the best roadmap.

5 Ways of Insulating a Greenhouse

  1. Basic Methods

Sealing cracks and ensuring doors and vents fit in securely are some of the most basic but effective steps to take in any greenhouse. This prevents heat loss by blocking out the cold air during winter and ensuring that all crops receive an equal amount of light.

It is also advisable to renew seals using any waterproof sealant and replace any fragile or broken panes. In case of excess ventilation, some sticky-back foam could come in handy to close up some parts.

Other techniques that are easy to install include:

  • Retaining some amount of snow on the roof during winter to provide supplementary insulation; as crazy as it sounds, obviously you can’t keep it, but not removing it can help.
  • Installation of aluminum or aluminized polyester plastic to the sidewall to reflect heat
  • Suspending pieces of fabric directly on top of plants at night to retain heat. The downside of using opaque fabric is that you would need to remove it during the day to let in sunlight.
  • Installing multiple skins of plastic (bubble polythene) to the roof that faces north, or to the sides of the house in a bid to trap warm air and save on heating costs. The bigger the bubbles, the better.

Double Glazing

Ardent gardeners from all over the world have proven this to be the most energy-efficient technique. Just like the name suggests, insulation is achieved by trapping air between two glass panes, thereby reducing condensation and preventing heat loss or gain. It is ideal since it permits the winter sun to light up and warm the structure while maintaining a constant amount of heat throughout.

However, this is by far the most expensive approach used in insulation; because the double glazed units are filled with dry nitrogen or argon gas to minimize conduction and give optimum results.

On top of that, it can only be installed in greenhouses that are being built. All things considered, it doesn’t hurt spending more and reaping long-term benefits. During the toughest weather conditions, this would be our recommended option.  

Base Cladding

Greenhouses made of fiberglass, though not as common, also have specific ways of insulation. With Base cladding, you have to install polystyrene panels or related material on the floor of the structure.

Heat is simply retained by blocking out the lowest bit of glass and ensuring the walls do not meet the glass on the ground. The only precaution to take in this method is remembering to remove the insulating material when summer comes. You don’t want to subject your crops to double heat.  

Rigid-board insulation

To control indoor energy consumption and give your greenhouse a touch of innovation, you should consider using the rigid foam insulation method. Sometimes, sealing gaps and cracks is not enough. In the event of such vulnerabilities, installation of high-performing foam on the walls could effectively close air leaks, consequently preserving valuable resources.

Rigid foams are made using extruded polystyrene (XPS) and polyisocyanurate which are moisture resistant, energy efficient, and flame retardant. Despite the sophisticated material- names, any vendor would know what a rigid foam is.

Use of Solar technology

If you are thinking of a more permanent solution, then solar technology is your best shot. The right solar greenhouse design could stabilize indoor temperatures effortlessly and store thermal energy all year long.

This reinforcement is more complex than it seems and has many implications. Around 15% of a structure’s heat loss occurs through the floor and this is the main focus with this approach. Depending on the type of foundation you have, a Ground to Air Heat Transfer (GAHT) system is installed underneath the greenhouse, either vertically or horizontally.

More heat will be trapped beneath, and prevent frozen soil from creeping in. This is one of the best methods that focus on heat exchange between the thermal mass of the soil and the greenhouse.

However, this procedure only works before construction and may require an expert on the same. Nonetheless, it is still a viable option.

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Additional tips

  • Ensure that your method of insulation does not affect the ventilation system or cast a shade on plants such as winter lettuce which need much light.
  • Install alarm systems that are triggered by power outages and temperature fluctuation for easier monitoring.
  • Using heavy insulation reduces light transmission, so only use it if you feel your plants will have a hard time making it through winter.
  • In the event of total failure of your system during winter, water your crops using tap water to keep them from freezing.
  • Use online resources and gardening apps to keep tabs on the conditions your plants thrive in.

In summary

Taking into account all the points discussed, insulating a greenhouse should not feel like rocket science; as long as you understand your type of crops and the climate of your environment.

By and large, these are some of the simplest and most effective ways of insulation, not just for greenhouses, but also for ordinary buildings.

Go ahead and join the hundreds, possibly thousands of gardeners who have insulated their own greenhouses! 

About Thomas Paxton 368 Articles
Hey there, I'm Thomas Paxton, your Tool Guru with a Twist! I've been knee-deep in the world of tools since I was a little tinkerer in my dad's shed. Now, I'm running my own website where I share my passion for tools and gardening products through buyers guides and insightful tips. I've got the knowledge and experience to break down complex concepts into simple, easy-to-understand language. I purchased Tools Review from Mike Jones at the start of 2023, he has done a sterling job of building the site and I hope I can continue in his success! When I'm not writing guides, you'll find me in my garden or garage, putting my skills to work and pushing the boundaries of creativity. So, whether you're a pro or just starting out, join me on this adventure, and let's conquer DIY projects together!

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