20 Greenhouse Terms to Know

    Posted on 09 April 2017

    If you have begun the process of greenhouse shopping you may find yourself faced with an array of unfamiliar terminology or maybe just some things you would like cleared up. We are here to help! Below is a list of common terms you will come across during your greenhouse search. 

    Greenhouse components

    greenhouse wall fan


    1. Sidewall: the straight side of the greenhouse. The length of this part determines your "Sidewall Height".
    2. Endwall: the front or back framing of the structure. Can be wood or metal. 
    3. Bow: the curved steel tubing that makes the top of the structure
    4. Gutter: the channel placed in the space on the roof between bays of a gutter connected greenhouse where the bows meet to accommodate water runoff.
    5. Purlin: the steel tubing that runs along the roof from the front to the back of the structure.
    6. Truss: the horizontal and vertical pipes that run from side to side in a greenhouse. These are not included in every structure. The provide additional support for structures in adverse weather conditions or in applications where there will be items hanging from the structure.


    7. Heater: usually hangs at the top of the structure with a vent that runs to the exterior. Generally, natural gas or propane powered, but electric heaters are available.
    *Heater Hanger Kit: Not visible in the photo, but it is used to hang the heater in the structure.

    Mechanical Ventilation

    8. HAF fan: Horizontal Air Flow fan is…also known as a circulating fan. Hangs in the roof of the structure to help move air.
    9. Shutter: available as manual or motorized. Opens to allow air flow through the structure.
    10. Wall Fan: Large exhaust fans placed in the endwall of a structure to pull air through the structure via shutters on the opposite endwall. Cooling systems can be added to the opposite endwall if needed.

    Natural Ventilation

    Roll up curtain kit Premium roll up curtain gear box Premium roll up curtain

    11. Roll up curtain:  opens via a manual crank handle, a gearbox, or a motor to allow passive exchange of air through the structure. 

    12. Roll bar: attaches to the curtain covering to roll up the material. Standard curtain kits come with a single roll bar. Premium kits have a double roll bar.

    13. Holdback: used to keep the curtain stable. Our holdbacks are metal tubing rather than cables and attach to the frame at every other sidewall post.

    14. Premium roll up curtain kit: upgrade of the standard roll up curtain to include a double roll bar, a gearbox with a brake, and woven curtain material.


    Shade cloth
    Greenhouse poly covering
    polycarbonate greenhouse covering
    Solawrap covering
    15. Shade cloth: a fabric used to help decrease the temperature in a structure and provide shade to plants. It can be the primary covering or it can be removable.
    16. Poly covering: the most common and economical covering. Generally available in 1-year and 4-year options. It has additives to protect itself from UV degradation. Other varieties are available such as anti-drip, string reinforced, and woven varieties.
    17. Polycarbonate: a hard panel covering. Available in corrugated, 6 mm and 8mm thicknesses and a variety of colors such as clear, opal, bronze, and blackout. It is a very durable and beautiful covering. Usually, it comes with a 10-year or 15-year warranty.
    18. Solawrap: Also known as "The Bubble Wrap Covering". It is very durable and insulates well. It comes in 4', 5', or 6' widths (depending on your bow spacing) and it is attached to the structure using tracks known as extrusions. It comes with a 10-year warranty against UV degradation. 


    Eave angle Base angle

    19. Eave angle: replaces the need for wood as a hip board. It is a piece of metal that runs down the side of the structure at the top of the sidewall where the tubing starts to bend for the bow. 
    20. Base angle: replaces the need for wood as a base board. It is a piece of metal that runs across the front and back of the structure at the base. It will also go down the sides of the structure if there are no roll up curtains. This is what you attach your Wire Lock Base to in order to hold down the bottom of your poly covering.

    There are many things to consider when designing your greenhouse or high tunnel kit. We have put together an ebook to help you with your process. Click below to get your copy.

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