Commercial Load Calculations for HVAC

Join CaptiveAire for a professional development hour (PDH) and learn the ins and outs of commercial HVAC load calculations--how to determine what tonnage unit you need and all of the factors at play in this decision. This topic is particularly helpful for anyone who works in HVAC, especially HVAC engineers and consultants, as well as building owners and anyone who wants to gain a deeper understanding of the decision making process when sizing commercial ventilation equipment. Learn more about CaptiveAire at captiveaire.com.

To receive PDH certification for this video, please visit CaptiveAire.com/library and click Request Access under the Professional Development section. Fill out the form on the pop up that appears and click Send. CaptiveAire will then add you to a professional development portal where you can access a certificate to confirm your training.

0:00 Introduction
2:49 Part 1 - The Loads
3:16 Envelope loads
5:38 Using correct weather data
6:39 Thermal swing
8:02 Infiltration vs. positive pressure
9:02 Internal loads
9:52 The forgotten loads
10:18 Daily load distributions
10:59 Ventilation loads
11:33 Ventilation code requirements (ASHRAE 62.1)
11:57 Demand controlled ventilation (DCV)
12:54 Ventilation required by exhaust rates
13:33 Weather impact on ventilation
14:44 Part 2 - The Software
14:53 Why we use software
16:41 Inputting the data
17:29 The software output - A load calculation
19:54 Part 3 - Equipment selection
20:54 Determining discharge temperature
24:41 Nominal vs. real world tonnages
25:56 Modeling equipment for real life applications
28:21 Weather impact on ventilation
30:46 Ventilation impact on airflows
36:14 Confusing “Capacity”
39:17 Part 4 - Sizing philosophies, a holistic approach
39:30 Critical applications
40:32 Kitchen discharge temperature vs. airflow
41:01 Considering other factors
42:44 The risks of oversizing
46:15 Sizing modulating equipment
47:03 Conclusion