Greenhouse ventilation is the movement of air from inside a greenhouse and replacing it with outside air to control high temperatures in the summer, to maintain relative humidity at acceptable levels during the winter and maintain acceptable carbon dioxide concentration levels.

Air movement also helps to improve plant respiration.  Solar powered fans are the most cost effective way to ventilate greenhouses with no utility expense.

Snap Fan solar fans / greenhouse fans cover an extensive range of ventilations requirements from 100 cubic feet per minute (cfm) to 6000 cubic feet per minute (cfm).

Snap Fan solar fan motors are either brushed or brushless.  The brushless motors have a higher up front cost, but require less maintenance and have a higher operating voltage.  This means they are suitable to running directly from most 300-400W class solar panels with a Voc or less than 50V or can run directly from solar/battery system up to 48V nominal (50V MAX).

All fans have accessories for finger guards, both inside and outside and louvered shutters.

Solar radiation through the greenhouse glazing raises the inside air temperature within the greenhouse. Summer greenhouse ventilation prevents the indoor temperature from rising too high above the outside air temperature.

The ventilation system must effectively move air directly through the crop and over the soil to prevent excessive temperature buildups around the plants. A generally accepted minimum ventilation rate for temperature control in the summer is one air change per minute.

Ventilation rates range from one air change every three minutes to three air changes per minute. As ventilation rates increase, the temperature difference between inside and outside air decreases.

Regardless of how high the ventilation rate in a greenhouse is in the summer, the inside air temperature during the day will never be as low as the outside air temperature. To maintain an inside air temperature below outside air temperature, evaporative cooling or some other means of conditioning the air must be used.

Winter greenhouse use may require a heating system or a passive heat sink like large volumes of water in storage. Regardless of the heating method, some ventilation will be required to keep relative humidity below 70 percent.

Two to three air changes per hour are typically adequate. One good way to provide the air movement needed to control humidity is to use the passive ventilation and a solar powered ceiling fan.

Air changes greater than 3 to 4 per hour will likely cause an increase in heating requirements.

The varying weather conditions during spring and fall require a combination of occasional temperature control and occasional humidity control. A ventilating fan system with multiple fans allow a better method of being able to control the ventilation according to the varying requirements.

Air Distribution Within Greenhouses = Horizontal Air Flow (HAF) Fans

Horizontal Air Flow fans maintain good air circulation within a greenhouse. In larger greenhouses, HAF fans should be mounted 10 to 15 feet from the greenhouse end walls  with additional fans spaced 30 to 50 feet apart.  Super Fans make great HAF fans.

The HAF idea keeps air moving just enough to provide a more uniform temperature throughout the greenhouse to control humidity as well as replace air at the plant level with air that has a higher carbon dioxide level. For an efficient system, the total fan capacity should be about two times the floor area. For example, in a 20 by 50 foot greenhouse, the fan capacity should be 20 by 50 by 2 = 2,000 cubic feet of air movement per minute. The number of fans needed can be calculated by dividing the capacity needed by the output of one fan.

Two 16 inch SnapFans would meet this requirement.

Ranges from 137cfm to 1555cfm depending on voltage (speed) and backpressure.

12" Brushless DC (BLDC) motor

• Brushless DC Motor - Designed to run direct on your solar or battery system
• Cubic feet per minute (CFM) output per watt, unmatched in industry
• Highest quality materials with an innovative design creates an efficient and quiet fan with all parts replaceable and/or serviceable 

12" HLE Brushless DC (BLDC) motor

• Runs directly off solar panel or battery bank
• High efficiency industrial grade Brushless Servo Motor
• Motor made in USA. Water resistant, O-ring seals, IP54
• Three discreet speed wire taps for user selected performance
• Soft start, thermal roll back and locked rotor protection are standard features
• Includes liquid tight conduit 5ft lead wires
• Low vibration mounting system reduces noise
• Glass reinforced polypropylene airfoil blade offers high efficiency and expanded air throw profile

Ranges from 225cfm to 2038cfm depending on voltage (speed) and backpressure.

16" Brushless DC (BLDC) motor

• Brushless DC Motor - Designed to run direct on your solar or battery system
• Cubic feet per minute (CFM) output per watt, unmatched in industry
• Highest quality materials with an innovative design creates an efficient and quiet fan with all parts replaceable and/or serviceable 

16" HLE Brushless DC (BLDC) motor

• Runs directly off solar panel or battery bank
• High efficiency industrial grade Brushless Servo Motor
• Motor made in USA. Water resistant, O-ring seals, IP54
• Three discreet speed wire taps for user selected performance
• Soft start, thermal roll back and locked rotor protection are standard features
• Includes liquid tight conduit 5ft lead wires
• Low vibration mounting system reduces noise
• Glass reinforced polypropylene airfoil blade offers high efficiency and expanded air throw profile

Ranges from 443cfm to 2518cfm depending on voltage (speed) and backpressure.

20" Brushless DC (BLDC) motor

• Brushless DC Motor - Designed to run direct on your solar or battery system
• Cubic feet per minute (CFM) output per watt, unmatched in industry
• Highest quality materials with an innovative design creates an efficient and quiet fan with all parts replaceable and/or serviceable 

20" HLE Brushless DC (BLDC) motor

• Runs directly off solar panel or battery bank
• High efficiency industrial grade Brushless Servo Motor
• Motor made in USA. Water resistant, O-ring seals, IP54
• Three discreet speed wire taps for user selected performance
• Soft start, thermal roll back and locked rotor protection are standard features
• Includes liquid tight conduit 5ft lead wires
• Low vibration mounting system reduces noise
• Glass reinforced polypropylene airfoil blade offers high efficiency and expanded air throw profile

24" Brushless DC (BLDC) motor

• Brushless DC Motor - Designed to run direct on your solar or battery system
• Cubic feet per minute (CFM) output per watt, unmatched in industry
• Highest quality materials with an innovative design creates an efficient and quiet fan with all parts replaceable and/or serviceable 

PASSIVE EXHAUST SHUTTER

• Specifically sized for your 16 inch Snap-Fan
• Corrosion resistant aluminum
• Protect the fan when its not running
• Keep warm air in when needed
• Passive - blown open by fan

• Required by OSHA is some situations
• Intake guards go inside of the building, exhaust guards go outside the building.

DC Thermostat control

• 10 amp DC Thermostat

• For use with DC Snap-Fans

• Help keep the warm air in when needed

• 4 Degree Fahrenheit Differential

Installation Instructions

Instruction Manual

Fan Dimensions

Wiring Diagrams