We strongly discourage the use of duct board wyes for splitting air flow to different areas. The estimated equivalent length of a duct board wye

Charles Watson, a British school teacher in the 1850’s notices he, and his students, are repeatedly getting sick in his classroom. He reasons that the indoor air quality has to be the source of the problem. Using well established principles he designs a non-electric mechanical Syphon Ventilator that introduces healthy air and displaces toxic air in the classroom. The results are far beyond his expectations. He goes on to share his invention with the world, installing over 13,000 ventilators throughout the United Kingdom. His insights and the applied principles are just as relevant today as they were in 1851. Sick buildings make people sick.

Here is a link to an article Paul wrote for HVAC Today. It is an overview of why Manual J is so crucial to proper

Manual J is a building science related engineering calculation that helps us put value on the structure’s ability to resist the loss and gain of

Why does my air conditioning system cost so much to run when it still doesn’t keep me comfortable? In the heating and air conditioning industry,

Welcome to our new website. Stay tuned for more information about Manual J, Manual D and Manual S HVAC system design. – The Manual J