Today on the Reschexpert blog we want to discuss some common questions we hear from DIY creators of Rescheck, Manual J heat loss, manual S equipment sizing, Manual D duct layouts, manual d duct sizing, and comcheck commercial energy reports.  We hope you enjoy the in depth technical questions we see on an everyday basis as a creator of home energy reports.

Are Kitchen, bathroom, and dryer vents separate and distinct from the HVAC systems?


Meaning, are these typically free stand units, independent of HVAC system:

  • Kitchen – Exhaust vent to outside of home
  • Bath vents to outside of home
  • Dryer vents directed outside of home.


If so, inclusion of bath vents throughout home, may need to be taken off HVAC duct system.  Maybe, maybe not.

Attached is ACCA Manual D Procedures.  Please see questions below.


From may Manual S, manual D, Manual J reports a friction rate of .10 IWC, required CFM per room (register), supply duct size per room (register)

  1. Should I assume all supply branches and trunks are round?  If not, what are the supply duct dimensions per room?
  2. From the Manual D Procedures, it appears that Supply Grill (register) size is based on CFM per room and recommended velocity.  Please provide Supply Grill sizes per room

There are 3 columns for Return Duct are provided in Manual D Report:

  • Please explain the difference of each return column. 
  • Please extend the full text of these 3 columns to view each respective column header
  • There 2 rows above the duct headers:
    • Row 1:  1200 / 600 / 400  — What do these columns mean (recommended fpm? If so, how does this help with duct sizing?) 
    • Row 2:  0.05 / 0.05 /0.05  — What does this mean?
  • A single Return Duct row is populated:
    • What is do 20/ 16/ 14 mean?
  • Are return duct branch and truck lines square, circular, oval?
  • Please provide Return Duct sizes per room
  • Please provide Return Grill (register) sizes


Formula Related Questions:

  • What software program are you running?
  • Please provide Friction Rate Calculation Worksheet?
  • What is the ASP – Available Static Pressure for each system?
  • What is the longest Supply Line?
  • What is the longest Return Line?


We hope you enjoyed these common questions as a provider of Rescheck, Comcheck, Manual J, Manual S, Manual D Duct layout we challenge you to answer as many as possible and let us know which ones stump you on the Reschexpert Twitter page.  As always we are here to help with any of your DIY FAQ home energy audit software questions on a daily basis.

Digiprove sealCopyright secured by Digiprove © 2019 Reschexpert Blog, Rescheck Podcast
Manual JSD Questions FAQ DIY FREE SOFTWARE Excel
Article Name
Manual JSD Questions FAQ DIY FREE SOFTWARE Excel
Manual JSD Questions FAQ DIY FREE SOFTWARE Excel
Publisher Name
Publisher Logo