Season Extension: Ventilation & Heating

To make your greenhouse more of a year round functioning entity, there are two main areas in which you have to make the structure more efficient-Heating and Ventilation.

1. Heating is your biggest expense for the winter so retaining heat is a priority.

The easiest way to retain heat in your greenhouse is to install a double poly cover with air in between. A small squirrel cage blower attached to the inside layer of plastic aids in maintaining air between layers.

The more dead air space between these layers you can create, the closer you will be to achieving a 30% reduction in heat loss. Holes will result in air movement and therefore less efficiency. 3″-5″ consistent space is ideal. It is a given that you would have less than that around the edges and over the ridge.

Double plastic will have a considerably longer life span. It is important to realize that as plastic gets older, the light transmission will be reduced which will reduce production.

Infrared plastic (IR poly) does further reduce heat loss and increase light diffusion so it can also be a consideration when looking for ways to reduce heating costs.

2. Ventilation is also one of your biggest considerations for the warmer times of the year. Ventilation can be done through forced or mechanical methods or passive through vents or roll up sides.

Vents are extremely effective since they can be placed higher up where the heat needs to be expelled. Mechanical ventilation is more costly both up front and to operate but it is easier to control since it is attached to a thermostat. For mechanical ventilation to be effective, it needs to be sized and located properly.

Roll up sides are less costly and simpler to install but are restricted by the fact that you have to be there to open and to close.

Climate control is especially challenging in the spring and the fall since most days you will have the need for both ventilating and heating.

One area that you need to be especially aware of is stagnant air. Without proper air movement, circulation and exchanging, stagnant air can cause many different types of diseases. It is important to understand what your plants require

Featured Add-On: Center Pivoting Gable Vent

We wanted to remind everyone of the center pivoting gable vent that we offer as a simple solution to the challenges of venting a building.

For venting to be effective, it has to be as high as possible. This is a cost effective alternative to costly roof vents.

Part of the window swings in and part of it goes out. Because of this

  • rain is never an issue
  • the window is easy to control even in extreme winds.
  • Incoming air is always deflected up to mix with the warmest air.
  • The tubular steel construction makes it both lightweight and resist twisting over time.

A continuous rope goes from the top of the window to a pulley at the ridge, down to ground level and back up to another pulley and then to the bottom of the window. By tying the rope off to an eye bolt on a gable post, this allows for very simple control from ground level.

Please don’t hesitate to call us for more details or with any questions you have about this option for your building!

vent3Vent4

Properly Venting a Building

Properly venting a building is a critical consideration when planning your building.

Getting rid of the initial ground moisture, quickly, when you have erected your new shelter is something many people do not think of. Quality air changes for plants or animals is something that automatically comes to mind. Getting rid of moisture is equally as important for storing your valuables.

Vent4Since warm air holds moisture and warm air rises, it is important to have venting capacity as high as is possible.

Venting through the roof, with individual turbines or a continuous roof vent, is the most effective but also the most costly.

This is only really necessary when you are in a very protected spot and there is a real need to keep the temperature down in a long building.

vent3Most medium length buildings that have the ends facing into the prevailing winds, can be adequately vented with gable end peak vents.

  • Make sure that these openings are as big as possible and as high as possible.
  • It is also important to make sure your “windows” can withstand the winds in your area.

Our centre pivoting gable vent has filled this requirement very effectively.

  • With part of the window going in and part of it going out, the wind can never get hold of it.
  • With the top and bottom rope through a double pully on the ridge, it is easy to maintain precise control over the opening area

As with all the other considerations, please do not hesitate to contact us with your specific set of circumstances and challenges