Here are some resources we've found helpful:

Mexico Renewable Energy Program (http://soar.nmsu.edu/mexico): The Mexico Renewable Energy Program unites the goals of promoting use of renewable energy systems and of enhancing economic and social development, creating new business opportunities, and offsetting greenhouse gas emissions

ASHRAE (http://www.ashrae.org): An international membership organization of engineers who create the worlds we live in.

UL (www.ul.com): Underwriters Laboratories Inc. (UL) is an independent, not-for-profit product safety testing and certification organization.

NOAA Weather Data (http://www.ncdc.noaa.gov): The National Climatic Data Center (NCDC) is the world's largest active archive of weather data.

Pressure Drop in Piping Calculator (http://www.processassociates.com/process/fluid/dp_1.htm)

DOE2.com (http://www.doe2.com): DOE-2 based building energy use and cost analysis software.

Typical Meteorological Year Weather Data (http://rredc.nrel.gov/solar/old_data/nsrdb/tmy2)

Online Psychrometric Calculator
(http://www.muntersamerica.com/Corp/calculator/calculator.htm)
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