Building your Greenhouse: Part 3

For our final installment of “Greenhouse 101″ we’ll learn about heating, ventilating and cooling the place that will serve as winter home to some of your plants, nursery to others and cool summer escape for still others.

As mentioned in part three, the type of heat your greenhouse requires will depend on where you live and the manner in which you build your greenhouse. While all greenhouses use solar energy, some will require an additional heating source, such as those in areas with little sun or extreme cold.

The passive solar energy system is the most used one in backyard greenhouses. With passive solar, a thermal mass, such as rocks or water-filled drums, is employed to capture heat during the day and radiate it back at night.

The active solar energy system involves pumping heated air into an energy storage area, such as water drums filled with rocks or the basement. With this type of system, you will need an electrical or other conventional source of energy to pump the heated air. This system does a better job of heating the greenhouse than passive solar heating; however it’s more expensive. You can gain a good understanding of solar heating and greenhouses at the National Sustainable Agricultural Service.

There also things you can do on a smaller level to help your plants receive even heating, such as painting containers black and filling them with water. Circulating fans will help maintain uniform by continually returning the rising heat downwards to plants.

For supplemental heating, a 220-volt circuit electric heater is often recommended for clean, efficient, and dependable heat. If the greenhouse is attached to the house, then the home heating system can probably be used.

Ventilation
The greenhouse will need proper ventilation for an exchange of inside air for outside air to control temperature, remove moisture, and to replenish carbon dioxide (CO2) that has been used by the plants through the day.

There are two ways to ventilate your greenhouse: naturally or mechanically. The natural method relies on roof vents that allow rising warm air to escape and that draw cool air in through the sides.

Mechanical ventilation utilizes an exhaust fan to move air out one end of the greenhouse while outside air enters the other end through motorized inlet louvers. The exhaust fans must be the correct size for the volume of air in the greenhouse.

Cooling
You can prevent your plants from withering in summer’s heat with various methods. Evaporative cooling in the form of a water cooler will cool and humidify your plants, but these systems don’t work well in humid climates. For the times of day when the summer sun is too intense, you can shade your greenhouse with a roll-up screen of wood or aluminum, vinyl netting or as many nurseries use, a shade cloth.

This concludes the three-part article on greenhouse building. Remember, while there is much information to assimilate and planning to do, most towns have a Master Gardener’s program nearby or a university’s extension service with knowledgeable folks who love to help. When using Websites, be sure they are of the authority type, such as the ones provided in this article. At the library you will likely run across many books about greenhouses published in the 70′s and 80′s, but be sure to look at newer ones too because there have been so many exciting developments to keep you and your plants happy.

In order to have better homes and gardens, patios can be arranged. There are a number of reasons why patio pavers are becoming reliable material for constructing and are used for outdoor patio design. If you want it to be covered there are a number of materials such as wood, concrete, fiber and glass available for patio gardening shade. Spanish style dwellings usually have patio sets between their homes and gardens.