Insulation Know-How

With volatile energy costs, a good return on investment may be obtained by adding insulation to homes, offices, farm shops and other heated buildings such as greenhouse headhouses or boiler rooms. Insulation can provide benefits in winter by keeping expensive heat in and in summer by keeping unwanted heat out.

Although all building materials have some insulation value, the term “insulation” usually refers to materials with a relatively high resistance to heat flow that are designed specifically for that purpose. …

Horizontal Air Flow is Best for Greenhouse Air Circulation

Before Horizontal Air Flow (HAF) systems were developed, it was common to find 10°F to 15°F difference in nighttime temperature between the opposite ends of a greenhouse. Plant growth and quality often reflected this unevenness. Today with a properly installed HAF system, there should be no more than 2°F difference anywhere in the greenhouse.

Understanding the basics

Horizontal air flow fans maintain good air circulation in this greenhouse full of vegetable seedlings. The first fan should be placed about 10′

Introduction to Greenhouse Efficiency and Energy Conservation


Greenhouses do their job most successfully using designs and siting for energy efficiency and maximum light transmission. Greenhouses must optimize crop growth and energy use by allowing sunlight in during the day, retaining as much heat as possible during cold weather, and providing sufficient ventilation to …

Geothermal Heat for Greenhouses

Soil and water below ground contain a vast reservoir of thermal energy. Geothermal heating systems recover this energy and convert it to heat that can be utilized in greenhouses and other buildings. Geothermal heat resources can be classified into three categories: low, medium, and high temperature.

Types of Geothermal Resources

  • Low temperature (50°F +/-). The soil temperature at the surface varies considerably over the year and closely follows the air temperature. At the 5 to 6 foot depth, the

Natural Ventilation in High Tunnels

Roll-up sides and drop-down curtains are low-cost vent systems that can be installed in most high tunnels. These systems operate on the principle that heat is removed by a pressure difference created by wind gradients, so no energy is required to operate fans to move air. A wind speed of 2-3 miles per hour is adequate to force cool air in the windward sidewall. The air traveling over the high tunnel creates a vacuum on the leeward side to pull …

Combat Higher Fuel Prices with Efficient Heating Systems

Heating fuel prices have been volatile over the past few years. How high they may go in the future will depend on many factors including the world fuel supply situation, demand, level of inflation and the weather. Good energy conservation measures can help to offset this increase and keep production costs under control.

Keeping the greenhouse heating system in peak operating condition is a good starting point. It can save by increasing efficiency, providing more uniform temperature in the growing …

High Tunnels – Low Cost Seasonal Growing Space

At a cost of $1 to $2 per square foot, a high tunnel can add low-cost growing space for season extension or plant protection. High tunnels also do not rely on as much energy inputs as traditional greenhouses with furnaces and forced-air ventilation. Growers and researchers are finding many innovative ways to utilize these structures to supplement their greenhouse operations.

By definition, the high tunnel is a walk-in, hoop or gothic-shaped pipe frame structure that is covered with a single …

Shell Corn as a Fuel for Greenhouse Heat


Corn has joined the list of popular alternatives to fossil fuels. Its high heat value, ease of handling, and ready availability in some sections of the United States have growers looking for information on cost, handling, and equipment suppliers. Although burning corn isn’t for everyone, a grower that is close to a good supply may find that it can reduce heating costs significantly.

Penn State Cooperative Extension has a Corn Energy Equivalent Table and an Energy Selector tool that …

Greenhouse Energy Conservation Checklist

High energy costs make conservation and efficient use of facilities an important part of today’s greenhouse operation. New greenhouse designs, better glazing, improved heating and ventilating equipment and new management systems should be included when upgrading or adding on. With typical annual energy usage being 75% for heating, 15% for electricity and 10% for vehicles, efforts and resources should be put where the greatest savings can be realized. The following checklist can help you make energy-saving improvements to a greenhouse …