HVAC Rooftop Units: Repair or Replace… or Enhance?
Monday, March 12, 2018 - 8:00am to 5:00pm
Training Overview:

Packaged roof top units (RTUs) are used to easily and effectively heat and cool more than 50% of all commercial buildings, but how long do they last out in the environment in the northern climates? Should you spend money to repair one when it finally fails or should you replace it with a new unit? Or should replace it before it fails? Are there ways to save energy on the existing or the new unit?
This course will use proven methods and easy to use (and free) software tools help to quantify the economic value of a repair, a new unit, or an energy conservation measure. OPTIONAL: PLEASE BRING YOUR LAPTOP TO CLASS TO INSTALL AND RUN THESE SOFTWARE TOOLS.

Event Benefits:

Learning Objectives:
As a result of this training, participants will be able to:
1. Install and use free software to analyze the economics of RTU replacements and improvements
2. Understand AHRI efficiency ratings for packaged RTUs
3. Know the RTU related requirements of the International Energy Conservation Code (IECC) 2015, which is the current code in Massachusetts
4. Select the appropriate RTU controls and accessories to maximize performance and efficiency
5. Be able to describe technologies such as economizers, demand controlled ventilation, staged air volume, and energy recovery ventilation

Who Should Attend:

NGRID Engineers
HVAC Techs
Plant Managers
All those interested in replacing or repairing HVAC units


1. Packaged Rooftop Unit (RTU) Overview
a. Technology Description
b. AHRI Efficiency Ratings
2. Programmable Thermostats
a. How and why?
b. Internet accessible
c. Simple thermostat vs. building automation systems (BAS)
d. IECC 2015 Code Requirements
e. Typical Energy Savings and Payback
3. Economizers
a. Technology Overview
b. Retro-fit Option?
c. Dry bulb vs. Enthalpy
d. IECC 2015 Code Requirements
e. Typical Energy Savings and Payback
4. Demand Controlled Ventilation (DCV)
a. CO2 Sensors and Technology Overview
b. The 2nd easiest retro-fit option for most RTUs
c. Is it required by energy code? Is it allowed by mechanical code?
d. Target Applications
e. Typical Energy Savings and Payback
5. Staged Air Volume (SAV)
a. How is SAV different than VAV?
b. What good is a VFD on a “constant volume” RTU?
c. How is it controlled?
d. Is it required by energy code?
6. Energy Recovery Ventilation (ERV)
a. Technology Overview
b. When does IECC 2015 energy code require an ERV?
c. Target Applications
d. Typical Energy Savings and Payback
7. Repair vs. Replace Customer Walk-thru Scorecard
a. Tool used to help engage the facility manager in the process
b. Assigns a score to the system used to help determine replacement
8. RTU Operating Cost Calculations & Software
a. Demonstrate free software tools, such as
i. Economizer Savings Estimator
1. Quick tool to determine energy savings for stat, economizer, and/or DCV added to existing RTUs
ii. Commercial INVE$T
1. Compares existing RTU performance to new RTU
2. Compares new RTUs of different efficiency levels
3. Includes enhancements such as economizer, DCV, ERV, and SAV
9. Zoning System Comparison (time permitting)
a. Variable Air Volume (VAV)
b. Variable Volume and Temperature (VVT)

Tools & References:

All materials will be available via email. Participants will have the opportunity to install software prior to training.

Mr. Ryan Hoger, LEED® AP BD+C
Workshop Cost:
Registration Details:

Checks will be accepted at the door.
Make checks payable to: University of Massachusetts-Amherst

University of Massachusetts Department of Mach. & Ind. Engineering
160 Governors Dr. Amherst, MA 01003-9265
Attn. Alberto Morales

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