"Professional       Design


 Building Sciences"

֎ Manual J, S, D, N

֎ HERS Energy Rating

֎ Blower Door Testing

   (Envelope Leakage Testing)

֎ Duct Leakage Testing

Marrs HVAC Services, LLC  is a leading international  Mechanical Design service. Our innovative designs and effective pricing promote professionalism worldwide. We work with Homeowners, HVACR companies, General Contractors, & Engineers to execute our commitment of Energy efficiency and total comfort. 

Our Featured Projects.

Standard Manual J, D, S for a Florida Home

Typically Homes in Florida have flex duct systems with the supply grille blowing air in the direction of the exterior wall which has the greatest Heat loss/gain.

Standard Manual N

 Duct Calculations and layout for commercial buildings across the USA. They will typically be metal duct, either rectangular or round. Some states will allow Duct Board and flex but it is not common outside of the SE USA.



Standard Manual J, D, S
for a home in the western, mid, & NE USA

Typically these homes are metal duct systems with the supply grille close to the exterior wall which has the greatest Heat loss/gain. Sometimes they may also incorporate flex no longer than 3’ in length. The metal Trunk will be either rectangular or round.


Mechanical Drawings

 These are typically completed for Architects and Engineers that require their documents to look as professional as possible.

Bad Habit Brewery Heat Load 2.jpg
Refrigeration Heat Load

 Refrigeration heat loads for  Wine cellars, Beer Coolers;  Walk in Coolers/ Freezers for Restaurants, Wineries, Breweries, and Morgues.



Stay In Touch.

Marrs HVAC Services, LLC




Tel: 833-626-8253

Doing business in all 50 US States, Canada, The Bahamas, & Australia

  • Facebook
  • Instagram
  • Twitter
  • YouTube
  • TikTok
Contact Us

© 2020 Property of Marrs HVAC Services LLC. All Rights Rerserved.