Skip to main content

Welcome to our Technical Page


If Someone Ask You, “How Do You Know Your Duct Designs Work”, What Would You Tell Them?

I recently read an article by David Richardson from the National Comfort Institute where he said, “If you want to start a fight among HVAC contractors, ask them how to design a duct system. On one side of the discussion, you’ll have those who follow duct design rules of thumb that came from previous generations. Those “rules” probably came from their dad or someone else who taught them as they came up in the trade. To this group, disrespecting those rules is like spitting in the face of tradition and on the same level as insulting their mom…On the other side is the duct design die-hards who follow industry-approved standards.”



Check out our Winter 2023 Training Schedule

The current edition of the NFPA 54 Code Book used by the State of New Hampshire is the 2018 edition.

The current edition of NFPA 58 (LP) Code Book used by the State of New Hampshire is the 2017 edition.

Want to learn more about Dual Fuel? Click on the Technical Library link on the right.

Email Club: Don’t forget to tell all your technicians about Randal’s Tech to Tech Column and the email club with industry updates, first chance to sign up for free NATE beta testing when available, and our class schedules. To join simply send your name in the body and “sign me up” in the subject line to or fill out the form below.

Total Air Supply, LLC
171 East Hollis Street
Nashua, NH 03060

Total Air SupplyTotal Comfort: Customer Service as it should be. Give us a call and let us show you…

FAX US: 1-603-889-7308


TAS Fall 2023 NH Gasfitter License Renewal Seminar Schedule & Registration Form

Simple Things to Do During Installation Of High Efficiency Furnaces to Prevent Condensate Build up and Callbacks