Solavent. How a Properly Vented attic Works

Innovative Natural Lighting
Solar Attic Fans That Make Sense.

How a Properly Vented attic Works:

An average 2000 sq. ft. home with a standard pitch will require 2 Solar powered attic ventilators to properly ventilate the attic space. Just as important to guarantee maximum exhaust of hot attic air is the amount of fresh "air intake". If your home has less than adequate "intake vents" you can cause a condition where the power exhaust vents will siphon the conditioned air from inside your home. Resulting in higher energy bills, and lost efficiency in the attic.
Our home of 2000 sq. ft. should have about 20 "intake vents" in the soffit or overhang, each not less than the standard 8"X16" size. If your home has "gable-type" vents high in the peak, than you will need to have a total of approximately 15-18 sq. ft. of actual free vent area. A good way to determine if your soffit vents are open is to stand in your attic with the lights off and opening closed, and look around the perimeter of your attic to see if light is visible. It is VERY common that these vents are blocked by over-blown insulation or the lack of baffles to keep these areas open and clean.

Please Note: This attic diagram does NOT show insulation for the purpose of clarity. Attic ventilation and proper insulation must work together as a system to prevent damage and maintain true energy efficiency. To achieve the correct balance of each products function, consult your local building codes and a licensed contractor. Attic ventilation without proper attic insulation is useless, and costs you money!

Basic Attic Venting Options:
Wind turbines (Whirlybirds): Average 2000 sq. ft. home needs about 9-10 to be effective. 1 wind turbine only vents an 'average' of 150 CFM (cubic feet per minute). requires reasonable wind to spin the turbine. What happens on hot days with no breeze? Or rainy days with no wind? Better than nothing though.

Ridge Vents: Designed to operate on the concept of 'convection' (natural process of "hot air rises" and is replaced by cooler air at the soffits) Again, useless in areas where you have less than a continuous wind of 5-8 mph. This product is reasonable for homes in wide open country areas with no trees or large structures to break the wind. And the plastic "mesh" type has to be blown clean every few years due to dirt, insects, tree debris clogging it. Still, better than nothing.

Electric Power Vents: Good choice for 'forced air' venting. Assures a continuous flow of air helping to maintain low levels of humidity and heat build-up. But, they cost money to operate and install (must run a new electric service to breaker) and have an average lifetime of about 2-3 years. Electric motors run very hot, and burn out.

Solar Powered Vents: Best choice for 'forced air' venting. Guarantee's a positive exhausting of hot, humid air, and introduction of cooling air without any further cost. Average lifespan of the SolarStar motors are around 10 years. These motors run at Low voltage (12 - 38 volts DC) and are totally sealed from outside air, eliminating debris clogging the motor. Cost $0 to operate, $0 to maintain, or $0 for wiring by a licensed electrician. The Gable unit is the best in our opinion because it eliminates a roof penetration and makes the best use of a "Gable' style home.

Those are the BASIC options you have to choose from. Remember, you are NOT trying to create a hurricane in your attic. Simply a good continuous exchange of air as long as the sun is up. And one more critical factor for ANY of these options to work is you must have enough "intake" area to allow the method you choose to draw in fresh air. No air in = No air out!

solavent@hotmail.com

Innovative Natural Lighting Solar Attic Fans That Make Sense.

Innovative Natural Lighting
Solar Attic Fans That Make Sense.