Session Number: PR-17

Indoor airPLUS Version 2: Humidification and Dehumidification: Methods and Controls

Paul Raymer - Senior Advisor Building Science

ICF, Cambridge, MA

About this program:

Controlling moisture is a major component for controlling indoor air quality.  The first step is to keep the water out. EPA’s Indoor airPLUS Program starts with bulk moisture management, but there are other key factors to consider with regard to moisture control.


Relative humidity (RH) conditions vary throughout the country. In hot, humid climates, Indoor airPLUS has previously addressed moisture vapor control with additional requirements for HVAC controls or dedicated dehumidification. But is this only a concern in hot, humid climates . . . or could it be a concern with high-performance homes in other regions?  Can an energy recovery ventilator (ERV) or heat pump water heater be used in lieu of a dehumidifier?  What about controls like dehumidistats – would be it be a good idea to use one to control a bath fan? What are the most effective ways to control the humidity in a building, and how does ventilation impact RH? On the other hand, is there a low end of the relative humidity scale where humidity needs to be added to the building?  

This session will examine some common challenges and best practices that address moisture vapor issues.  Attendees will have a chance to preview various approaches to controlling RH and learn how requirements in EPA’s Indoor airPLUS Program are continuing to evolve in Version 2 of the Construction Specifications.


About the Presenter:

Paul H. Raymer has been working with building science for more than forty years.  He is a Senior Advisor with ICF and the Chief Investigator for Heyoka Solutions and President of the NorthEast Building Science Institute.  He is the author of the Residential Ventilation Handbook V2 (Salty Air Publishing, 2017), Recalculating Truth (a novel) (Salty Air Publishing, 2014), Residential QCI Handbook (Salty Air Publishing, 2015).  He was a member of the LEED EA Technical Advisory Subcommittee, BPI’s Standards Technical Committee, and is Subcommittee Chair for Heating, Cooling, and Ventilation of the NREL SWS.  He is BPI Envelope, Building Analyst, Heating Professional, AC/Heat Pump, and Healthy Home Evaluator certified and a certified HERS Rater. He is an IREC assessor, IREC Certified Master Trainer and he is a full member of ASHRAE (a voting member of the 62.2 SSPC).

Program Level: Intermediate-Advanced

Content Area(s): Building Design & Construction (including Green), Occupant Health/Medical Issues, Energy Efficiency, High Performance Buildings, Facility Operations & Management, Investigations, Testing & Research