R-Values & Indoor Air Quality   R-values are empirical measurements that are based on laboratory conditions. Unfortunately insulation is used in various environments and is often installed incorrectly (compressed, void in hard-to-reach areas, etc.). This results in much smaller R-Values than advertised. This reduction in installed R-value can be as much as 50 percent.   R-values also do not take in to account the effects that air permeability and temperature differential have on insulation in the field. Our Air Infiltration Demonstrator graphically shows that traditional R-values are not the most reliable method of determining the true ability of an insulating product. You must also consider the quality of installation and the air permeability of the insulation you chose.   With All Tech Industries' you get a perfect installation every time, filling every nook and cranny - leaving no gaps or voids. You also get a lifetime product that will not settle or sag and one that has low air permeability.   If you don't see your solution listed, contact an All Tech Industries engineer today (989-826-9999) for a deeper discussion about your insulation requirements.           What is the Thermal Envelope (air leaks)? The thermal envelope or closed attic approach is an advanced development for hot and humid climates.   A growing body of research from ASHRAE, D.O.E., FSEC (Florida Solar Energy Center) and the Building Science Corporation, suggests that ventilating an attic may be counterproductive. The traditional methods of attic ventilation (gable vents, turbines, soffit and ridge-vent assemblies) do eliminate a small amount of heat, but this method tends to bring, into the attic, large volumes of moist air.   Furthermore, recent research from PATH (Partnership to Advance Technology in Housing) indicates that when we place air distribution systems and/or duct work in an unconditioned space we may incur a very large energy penalty (up to 30%).   In summary, using the "Thermal Envelope" approach allows you to create a one conditioned space within your house. It ensures that your ductwork is in a conditioned or semi-conditioned space, therefore reducing your energy loss. Also with Spray Foam Insulation, you have virtually sealed your house from top to bottom and you are now able to effectively control the air quality within your home.   If you don't see your solution listed, contact an All Tech Industries engineer today (989-826-9999) for a deeper discussion about your insulation requirements.