Munters Heat Exchangers DOAS Review: Cost to Operate & Energy Analysis Brad Perdew Applications Engineer 8/27/12 DOAS Review: Cost to Operate & Energy Analysis Mike Herwald Regional Sales Manager October 7, 2015 mike.herwald@munters.com

DOAS Unit Comparison Brute Force Condenser Heat Reactivated Desiccant (HCUc) Enthalpic Heat Recovery (Single Wheel) Enthalpic Plus Sensible Heat Recovery (Wringer Plus) Condenser Heat Reactivated Plus Enthalpic Recovery (ERV)

Assumptions Baltimore TMY Bin Data – All Hours 10,000 CFM, 45 Dew-Point, Neutral Supply Required $0.08/Kwh and $12/Million BTUH, COP=3, 80% Heat 75% Enthalpic Recovery 60% Sensible Reheat Effectiveness Reheat Available from Compressor – 15 Deg. Max Reheat Cost Assessed 72 Deg. and Cooler

Cost to Operate Comparison

HCUc vs. Single Wheel Base Line

HCUc vs. Single Wheel Base Line

Wringer Plus vs. DryCool ERV

Wringer Plus vs. DryCool ERV

Cost to Operate Comparison

DOAS Comparison Recap The Most Efficient Systems Provide Reheat that is not “Hot Gas Reheat” (Heat Exchanger or Desiccant Reheat) Dual Heat Exchanger Systems Dominate with Superior summer and winter performance characteristics Condenser Heat Reactivated Desiccant Provides the Minimum DH Compressor Size – Lower KW/Ton and Better MRE Efficient DOAS systems, ie Wringer Plus or ERV can payback very quickly vs. brute force options

DOAS Recap 45 Dew-Point Dry Air Required for “People Driven Outside Air” Reheat systems required, and reheat systems can drastically increase recovery potential All DOAS Systems should be viewed the same, chilled beam or not The most efficient Systems are not Necessarily the most Expensive Evaluate DOAS offering for meeting outdoor air needs – There are many offerings that DO NOT include required performance

Questions