Skip to content
Select Your Language

Selecting a language changes the language and content on the Trane site.

  • United States English
  • Canada English French
  • Argentina Spanish
  • Mexico Spanish
  • Brazil Portuguese
  • Aruba English
  • Bahamas English
  • Belize English
  • Bermuda English
  • Bolivia Spanish
  • Bonaire English
  • Chile Spanish
  • Colombia Spanish
  • Costa Rica Spanish
  • Dominican Republic Spanish
  • Ecuador Spanish
  • El Salvador Spanish
  • Grenada English
  • Guadeloupe English
  • Guatemala Spanish
  • Guyana English
  • Haiti English
  • Jamaica English
  • Martinique English
  • Netherland Antilles English
  • Nicaragua Spanish
  • Panama Spanish
  • Paraguay Spanish
  • Peru Spanish
  • Puerto Rico Spanish
  • Saint Lucia English
  • St. Vincent & Grenadines English
  • Suriname English
  • Trinidad & Tobago English
  • Venezuela Spanish
  • Armenia English
  • Austria German
  • Belarus Russian
  • Belgium English
  • Croatia English
  • Czech Republic Czech
  • Denmark English
  • Estonia English
  • Finland English
  • France French
  • Georgia English
  • Germany German
  • Greece Greek
  • Hungary Hungarian
  • Israel English
  • Ireland English
  • Italy Italian
  • Kazakhstan Russian
  • Latvia English
  • Lithuania English
  • The Netherlands Dutch
  • Norway English
  • Poland English
  • Portugal Portuguese
  • Romania English
  • Russia Russian
  • Serbia Russian
  • Slovakia Czech
  • Slovenia English
  • Spain Spanish
  • Sweden English
  • Switzerland French German Italian
  • Turkey Turkish
  • Ukraine English
  • United Kingdom English
  • Azerbaijan Русский
  • Tajikistan Русский
  • Uzbekistan Русский
  • Turkmenistan Русский
  • United Arab Emirates English
  • Qatar English
  • Kuwait English
  • Egypt English
  • Lebanon English
  • Mainland China Simplified Chinese English
  • Korea, Republic of (South Korea) Korean English
  • Vietnam Vietnamese English
  • India English
  • Australia English
  • Japan Japanese
  • Guam English
  • Thailand Thai English
  • Taiwan Traditional Chinese English
  • Hong Kong SAR English
  • Indonesia English
  • Malaysia English
  • Philippines English
  • Singapore English
  • New Zealand English

ComfortSite Login

Trane ComfortSite is an extranet site designed to save you time. With your secure login, you can:

  • Order Equipment, Parts, Literature and track Order Status
  • View product literature
  • Register for Training programs
  • Complete Warranty requirements online
  • Search for specific Product Information
  • Use interactive Product Support functions
  • View and print invoices through Account Track Online
  • and More
Log In

Trane Connect

This is the login for Trane® Connect™ and other Trane® commercial applications. Trane® Connect™ is our secure, cloud-based customer portal to access your building systems to remotely monitor and manage building systems, and conduct routine maintenance.

Log In
Trane Commercial
  • Services
    • Services
    • Decarbonization & Electrification
      • Decarbonization & Electrification
      • Decarbonization Solutions
      • Energy Efficiency Solutions
      • Electrification of Heat Solutions
      • Refrigerant Management Solutions
      • Renewable Energy & DERs
    • Energy Services
      • Energy Services
      • Monitoring & Validation
      • Sustainability & Decarbonization
      • Distributed Energy Resources (DERs) for Resilience
      • Conservation & Optimization
      • Financing & Implementation
      • Infrastructure Renewal
    • Operate, Maintain & Repair
      • Operate, Maintain & Repair
      • Connectivity & Cloud Services
      • HVAC System Management
      • HVAC System Repair
    • Upgrade & Modernize
      • Upgrade & Modernize
      • Building Systems
      • HVAC System Retrofits
      • HVAC Equipment Upgrades
      • Infrastructure Renewal
      • Financing & Implementation
    • Rentals
      • Rentals
      • Air Conditioners
      • Air Handlers
      • Cooling Towers
      • Chillers
      • Heating Equipment
      • Generators
      • Emergency Response
      • Planned Maintenance
      • Contingency Planning
    • Indoor Environmental Quality (IEQ) Solutions
      • Indoor Environmental Quality (IEQ) Solutions
      • Indoor Air Quality
      • Thermal Comfort
      • Our 3-Step Process
      • Lighting
      • Acoustics
      • IAQ Services
  • Products & Systems
    • Products & Systems
    • VRF & Ductless Solutions
      • VRF & Ductless Solutions
      • N-Gen CITY MULTI VRF
      • P Series
      • Nv Series
      • HVRF
      • SMART MULTI®
    • Chillers
      • Chillers
      • Air-Cooled Chillers
      • Chiller Heaters
      • Comprehensive Chilled Water Systems
      • Comprehensive Chiller-Heater Systems
      • Modular Chillers
      • Process Chillers
      • Water-Cooled Chillers
    • Packaged Units & Split Systems
      • Packaged Units & Split Systems
      • CoolSense® Integrated Outdoor Air Systems
      • Intelligent VAV Systems
      • Zoned Rooftop Systems
      • Rooftop Units
      • Split Systems
      • Self-Contained Units
      • Water Source Heat Pumps
      • Dedicated Outdoor Air Units
    • Heat Pumps
      • Heat Pumps
      • Heat Pumps
      • Air-to-Water Heat Pumps
      • Electrification of Heat
      • Comprehensive Chiller-Heater Systems
    • Controls & Building Automation Systems
      • Controls & Building Automation Systems
      • Controls for Large Buildings & Campuses
      • Controls for Small Buildings
      • Wireless Systems
      • Lighting Solutions
      • Controls Solutions for Light Commercial Contractors
      • Cybersecurity
    • Air Handling
      • Air Handling
      • CoolSense® Integrated Outdoor Air Systems
      • Sensible-Cooling Terminal Unit
      • Terminals
      • VAV (Variable Air Volume) Units
      • Performance Air Handlers
      • Air Handler Accessories
      • Unit Heaters
      • Air Rotation Units
    • Thermal Energy Storage
      • Thermal Energy Storage
      • Thermal Battery Systems
      • Thermal Energy Storage Solutions
    • Design & Analysis Software
      • Design & Analysis Software
      • TRACE® 3D Plus
      • Trane® Design Assist™
      • myPLV®
      • Trane® Select Assist™ (Formerly known as TOPSS™)
      • myC02e™
      • Calculators & Charts
      • View All Design & Analysis Tools
    • Trane Drives
      • Trane Drives
      • TR200 Variable Frequency Drive
    • Liquid Cooling Systems
      • Liquid Cooling Systems
      • Coolant Distribution Unit (CDU)
  • Training & Support
    • Training & Support
    • Education & Training
      • Education & Training
      • Trane HVAC Education & Training
      • Trane University
      • Trane Education Center
      • Design & Analysis Tools Training
      • Engineers Newsletters & Engineers Newsletters Live!
      • Becoming a Trane Technician
    • Engineer & Contractor Support
      • Engineer & Contractor Support
      • Engineering Support
      • Contractor Support
      • Trane C.D.S. Software Support
      • BIM-Revit Library
    • Financing Support
      • Financing Support
      • OMNIA Partners
      • Anticipation Discount Program
      • Energy Savings Performance Contracting (ESPC)
      • Cooperative and Group Purchasing
      • Financing
    • Legislation and Incentives Resource Center
      • Legislation and Incentives Resource Center
      • View Legislation and Incentives Resource Center
      • Trane Equipment Rebate Finder
  • Industries
    • Industries
    • Commercial Real Estate
    • Data Centers
    • Food & Beverage
    • Federal Government
    • Fulfillment Centers
    • Grocery & Supermarkets
    • Healthcare
    • Higher Education
    • High Tech
    • Hospitality
    • Indoor Agriculture
    • Industrial
    • K-12
    • Life Sciences
    • Local Government
    • Restaurants
    • Retail Buildings
    • National Accounts
  • About
    • About

    • About Us
    • Contact Us
    • Locate a Sales Office
    • Trane Newsroom
    • Customer Stories
    • Trane Blog
    • Events & Webinars
    • Press Releases
    • Looking for Parts?
    • Safety Data Sheets
      • North America

      • United States English
      • Canada English French
      • Latin America

      • Argentina Spanish
      • Mexico Spanish
      • Brazil Portuguese
      • Aruba English
      • Bahamas English
      • Belize English
      • Bermuda English
      • Bolivia Spanish
      • Bonaire English
      • Chile Spanish
      • Colombia Spanish
      • Costa Rica Spanish
      • Dominican Republic Spanish
      • Ecuador Spanish
      • El Salvador Spanish
      • Grenada English
      • Guadeloupe English
      • Guatemala Spanish
      • Guyana English
      • Haiti English
      • Jamaica English
      • Martinique English
      • Netherland Antilles English
      • Nicaragua Spanish
      • Panama Spanish
      • Paraguay Spanish
      • Peru Spanish
      • Puerto Rico Spanish
      • Saint Lucia English
      • St. Vincent & Grenadines English
      • Suriname English
      • Trinidad & Tobago English
      • Venezuela Spanish
      • Europe

      • Armenia English
      • Austria German
      • Belarus Russian
      • Belgium English
      • Croatia English
      • Czech Republic Czech
      • Denmark English
      • Estonia English
      • Finland English
      • France French
      • Georgia English
      • Germany German
      • Greece Greek
      • Hungary Hungarian
      • Israel English
      • Ireland English
      • Italy Italian
      • Kazakhstan Russian
      • Latvia English
      • Lithuania English
      • The Netherlands Dutch
      • Norway English
      • Poland English
      • Portugal Portuguese
      • Romania English
      • Russia Russian
      • Serbia Russian
      • Slovakia Czech
      • Slovenia English
      • Spain Spanish
      • Sweden English
      • Switzerland French German Italian
      • Turkey Turkish
      • Ukraine English
      • United Kingdom English
      • Azerbaijan Русский
      • Tajikistan Русский
      • Uzbekistan Русский
      • Turkmenistan Русский
      • Middle East

      • United Arab Emirates English
      • Qatar English
      • Kuwait English
      • Egypt English
      • Lebanon English
      • Asia Pacific

      • Mainland China Simplified Chinese English
      • Korea, Republic of (South Korea) Korean English
      • Vietnam Vietnamese English
      • India English
      • Australia English
      • Japan Japanese
      • Guam English
      • Thailand Thai English
      • Taiwan Traditional Chinese English
      • Hong Kong SAR English
      • Indonesia English
      • Malaysia English
      • Philippines English
      • Singapore English
      • New Zealand English
  • Decarbonization & Electrification
  • Decarbonization Solutions
  • Energy Efficiency Solutions
  • Electrification of Heat Solutions
  • Refrigerant Management Solutions
  • Renewable Energy & DERs
  • Energy Services
  • Monitoring & Validation
  • Sustainability & Decarbonization
  • Distributed Energy Resources (DERs) for Resilience
  • Conservation & Optimization
  • Financing & Implementation
  • Infrastructure Renewal
  • Operate, Maintain & Repair
  • Connectivity & Cloud Services
  • HVAC System Management
  • HVAC System Repair
  • Upgrade & Modernize
  • Building Systems
  • HVAC System Retrofits
  • HVAC Equipment Upgrades
  • Infrastructure Renewal
  • Financing & Implementation
  • Rentals
  • Air Conditioners
  • Air Handlers
  • Cooling Towers
  • Chillers
  • Heating Equipment
  • Generators
  • Emergency Response
  • Planned Maintenance
  • Contingency Planning
  • Indoor Environmental Quality (IEQ) Solutions
  • Indoor Air Quality
  • Thermal Comfort
  • Our 3-Step Process
  • Lighting
  • Acoustics
  • IAQ Services
  • VRF & Ductless Solutions
  • N-Gen CITY MULTI VRF
  • P Series
  • Nv Series
  • HVRF
  • SMART MULTI®
  • Chillers
  • Air-Cooled Chillers
  • Chiller Heaters
  • Comprehensive Chilled Water Systems
  • Comprehensive Chiller-Heater Systems
  • Modular Chillers
  • Process Chillers
  • Water-Cooled Chillers
  • Packaged Units & Split Systems
  • CoolSense® Integrated Outdoor Air Systems
  • Intelligent VAV Systems
  • Zoned Rooftop Systems
  • Rooftop Units
  • Split Systems
  • Self-Contained Units
  • Water Source Heat Pumps
  • Dedicated Outdoor Air Units
  • Heat Pumps
  • Heat Pumps
  • Air-to-Water Heat Pumps
  • Electrification of Heat
  • Comprehensive Chiller-Heater Systems
  • Controls & Building Automation Systems
  • Controls for Large Buildings & Campuses
  • Controls for Small Buildings
  • Wireless Systems
  • Lighting Solutions
  • Controls Solutions for Light Commercial Contractors
  • Cybersecurity
  • Air Handling
  • CoolSense® Integrated Outdoor Air Systems
  • Sensible-Cooling Terminal Unit
  • Terminals
  • VAV (Variable Air Volume) Units
  • Performance Air Handlers
  • Air Handler Accessories
  • Unit Heaters
  • Air Rotation Units
  • Thermal Energy Storage
  • Thermal Battery Systems
  • Thermal Energy Storage Solutions
  • Design & Analysis Software
  • TRACE® 3D Plus
  • Trane® Design Assist™
  • myPLV®
  • Trane® Select Assist™ (Formerly known as TOPSS™)
  • myC02e™
  • Calculators & Charts
  • View All Design & Analysis Tools
  • Trane Drives
  • TR200 Variable Frequency Drive
  • Liquid Cooling Systems
  • Coolant Distribution Unit (CDU)
  • Education & Training
  • Trane HVAC Education & Training
  • Trane University
  • Trane Education Center
  • Design & Analysis Tools Training
  • Engineers Newsletters & Engineers Newsletters Live!
  • Becoming a Trane Technician
  • Engineer & Contractor Support
  • Engineering Support
  • Contractor Support
  • Trane C.D.S. Software Support
  • BIM-Revit Library
  • Financing Support
  • OMNIA Partners
  • Anticipation Discount Program
  • Energy Savings Performance Contracting (ESPC)
  • Cooperative and Group Purchasing
  • Financing
  • Legislation and Incentives Resource Center
  • View Legislation and Incentives Resource Center
  • Trane Equipment Rebate Finder
  • Commercial Real Estate
  • Data Centers
  • Food & Beverage
  • Federal Government
  • Fulfillment Centers
  • Grocery & Supermarkets
  • Healthcare
  • Higher Education
  • High Tech
  • Hospitality
  • Indoor Agriculture
  • Industrial
  • K-12
  • Life Sciences
  • Local Government
  • Restaurants
  • Retail Buildings
  • National Accounts
  • About Us
  • Contact Us
  • Locate a Sales Office
  • Trane Newsroom
  • Customer Stories
  • Trane Blog
  • Events & Webinars
  • Press Releases

CONTACT A TRANE EXPERT

Blog

Published: May 24, 2023

Trane Engineers Newsletter: Using Hot Gas Reheat for Humidity Control

Quick Facts

Topics
Engineers Newsletter
Greg DuChane, Applications Engineer

About the Authors

Greg DuChane, Applications Engineer

 

 

 

Greg joined Trane in 1989 after earning a Bachelor’s Degree in Mechanical Engineering from Purdue University. Throughout his 34-year tenure, he’s worked with large, national retail and restaurant chains in various capacities—first as an account executive for Trane National Accounts, then as a regional sales manager for Trane’s global business development group, and recently as Key Accounts Sales Leader. His considerable experience with the application of unitary and dedicated outdoor-air systems, as well as ventilating the commercial kitchens of large restaurant chains, gives him a unique perspective on how such applications affect the HVAC systems in restaurant and retail applications.

Greg is past Chair of ASHRAE Technical Committee 5.10, Commercial Kitchen Ventilation, and is the current handbook chair. He is also a member of the Restaurant Facilities Managers Association (RFMA) Education Committee, a frequent speaker at their conferences, and a member of SPECS where he served on the Advisory Board.

Eric Strum, Applications Engineer

Eric Sturm, Applications Engineer

 

 

 

 

Eric joined Trane in 2006 after graduating from the University of Wisconsin – Platteville with a Bachelor of Science degree in Mechanical Engineering. Prior to joining the Applications Engineering team, he worked in the Customer Direct Services (C.D.S.) department as a marketing engineer and product manager for the TRACE™ 700 load design and energy simulation application.

In his current role as an applications engineer, Eric’s areas of expertise include acoustics, airside systems, indoor agriculture, and indoor air quality. He is currently involved with ASHRAE® as a member of the Standard 62.1 project committee, the indoor agriculture technical committee, and the sound and vibration technical committee. Eric is the recipient of the ASHRAE Distinguished Service Award and Young Engineers in ASHRAE Award of Individual Excellence.

The humidity level inside a building is a core component of occupant comfort. For decades, many HVAC systems have relied on coincidental (or “passive”) dehumidification, which attempts to maintain zone humidity through the active control of zone temperature. This meant that systems were controlled to maintain the zone dry-bulb temperature at a desired setpoint and hope that the resulting flow of cool, dry supply air was sufficient to prevent the zone humidity level from rising too high.

Beginning with its 2019 version, ASHRAE® Standard 62.1 (Ventilation and Acceptable Indoor Air Quality) includes a more stringent requirement for the control of indoor humidity. This standard now requires a maximum indoor dew point temperature of 60°F, during both occupied and unoccupied hours, whenever the outdoor air dew point temperature is above 60°F. This will likely result in more HVAC systems being designed with “active” humidity control.

tc-enl-gas-reheat.jpg

Particularly in packaged, direct-expansion (DX) equipment, hot gas reheat is a popular means for providing active humidity control. Hot refrigerant vapor leaving the compressor is diverted by a valve so that it flows through a reheat coil, which is located downstream of the cooling coil (evaporator) in the airstream. Heat is transferred from the hot refrigerant vapor to reheat the cool, dehumidified air leaving the evaporator. This can enable active control of both the zone dry-bulb temperature and the zone humidity level. And it uses heat that is recovered from the refrigeration system; heat that would otherwise have been rejected outside the building.

In this Engineers Newsletter (EN), Trane applications engineers Eric Sturm and Greg DuChane explain the new humidity control requirement in Standard 62.1, walk through a psychrometric analysis that demonstrates the need for “active” humidity control at part-load operating conditions, explain how hot gas reheat is controlled in both a single-zone system and a multiple-zone VAV system, and discuss the benefits of modulating control of the hot gas reheat valve compared to staged or cycled control.

Download the latest issue of the Engineers Newsletter (EN) to read it now.

Engineers Newsletter

Subscribe to the Engineers Newsletter

More about Trane Engineers Newsletters

Engineers Newsletters are topical, informative articles that provide engineering professionals who design HVAC systems with reliable, objective, and technologically current information in a non-commercial format. They've been published by Trane’s Applications Engineering team since 1972 and have long been a trusted technical resource throughout the industry. Subjects range from HVAC system configurations to acoustics to interpretation of ASHRAE standards.

Engineers Newsletters are provided to customers free-of-charge. Current and past issues can be viewed on trane.com/EN, and you can even subscribe to receive e-mail notification when a new issue is published.

  • Energy and Building Services
  • Products and Systems
  • Education & Training
  • Newsroom
  • About Us
  • About Trane
  • Wellsphere™
  • Newsroom
  • Customer Stories
  • Contact Us
  • Locate a Sales Office
  • Engineering Support
  • Contractor Support
  • Careers
  • Environmental Compliance
  • Quality
  • Ethical Business Conduct
  • Supplier Terms
  • Facebook
  • Twitter
  • LinkedIn
  • YouTube

Privacy Policy  |   Terms of Use

All trademarks referenced are the trademarks of their respective owners.

© 2025 Trane. All Rights Reserved.

Trane Technologies