ASHRAE is arguably most important association that directly impacts and interacts with the energy efficiency industry.
ASHRAE is an acronym which stands for the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE). The building discipline that ASHRE serves is the Mechanical Engineer (ME) who is the building design professional that is concerned with building occupant comfort.
Consequently, mechanical engineers need to know all about the building like, the number of occupants and what they'll be doing in the building, (sitting doing office work, dancing the tango, doing brain surgery).
All of these are called "end-use" and have a significant impact on the comfort systems and closely related - energy consumption. MEs need to know the kind of and quantity of light being used in a building because lighting produces along with light, heat, which contributes to the "cooling load" of the building. Cooling loads need to be offset with air conditioning which is designed by the ME. The ME needs information about the building construction materials, type and color of the carpeting, color of the walls, materials used for in the furnishings, operating hours, occupancy profiles (when most of the occupants are in the building). All of these things add to the understanding of the building that the ME uses to design the comfort systems.
All of that to tell you that ASHRAE is very serious about doing this comfort system design stuff right and therefore, spends a lot of time figuring out things like the absolute insulation value of the (Pink Panther) fiberglass insulation used in most residential construction walls, ceilings, and floors. Fundamental information is found in the ASHRAE Fundamentals Handbook which is one of four volumes that is updated once every four years. Joining ASHRAE gets you a new volume every year which is updated through research done by ASHRAE technical committees. ASHRE has a student membership rate.
Find ASHRAE and a state or regional chapter at: http://www.ashrae.org/