Impact of Temperature on Occupants: Theory vs. Reality OPFMA 2004 Annual Conference November 17, 2004 EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Thanks & Introductions Hi, my name is… Thanks & Introductions Stephen Petty, P.E., C.I.H. Energy & Environmental Solutions, Inc. President Joseph A. Ventresca Energy Coordinator, City of Columbus EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Objective(s) ASHRAE 55 – Impacts Effects of Register Temp. On Human Comfort Real World Thermal Comfort Experiences. What is This All About ... EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

ASHRAE 55 – 2004/1995/1992/1981 EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

ASHRAE 55 Overview Basis: Defines indoor human thermal comfort conditions for any building types. Based on majority conditions – 80% overall acceptability (80% satisfied; 20% dissatisfied). Based only on thermal (temperature) so: No lower limit set since no lower limit relates to thermal comfort. Nevertheless, upper limit(s) provided since non-thermal factors affect comfort. EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

ASHRAE 55 – Changes in Upper Humidity Limits With Time Date Value Basis 1981 Humidity Ratio: 0.012 IAQ Considerations 1992 Summer: 60% R.H. Relative Humidity Winter: 60% R.H. (Environmental Basis) 1995a Summer: 68F w.b. Wet-Bulb Temperature Winter: 64F w.b. (Thermal Not Environ. Basis) 2004 Humidity Ratio: 0.012 Back to 1981; systems designed to control humidity. D.P. 62.2 F (R.H. of 76% at 70F and R.H. of 54.6% at 80F). EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

ASHRAE 55 – Humidity Plots 2004 Edition 1995a Edition EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

ASHRAE 55 – Other Comfort Conditions (Floor Temp ASHRAE 55 – Other Comfort Conditions (Floor Temp./Temp Variations – 15 minute Intervals) Floor Temp: Basis: 10% Dissatisfied – 66.2F to 84.2F wearing normal indoor Shoes; doesn’t apply to people who are barefoot or sitting on the floor. 15 Minute Interval Temperature Variation: 2.0F. EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

ASHRAE 55 – Other Comfort Conditions (Indoor vs. Outdoor T) EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

ASHRAE 55 – Other Comfort Conditions (Radiant Temps.) EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

ASHRAE 55 – Other Comfort Conditions (Air Speed) EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Delivered Air At Register Real World Example EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Delivered Air At Register For the Same Load, How Does Different Delivered Air Temperatures Impact Comfort? EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Consider the Following Situation Home Load: 66,500 BTUH (e.g., 80,000 BTUH furnace at 82% efficiency) Return Air Temperature: 65F Relative Humidity: 50% Delivered Air Temperature: 70F to 120F What is the Volumetric Flow Rate and Velocity vs. Supply Temperature? EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Observations For the same heat load to the home, the amount of air required changes from 2,445 CFM at 90F supply air to 1,186 CFM at 120F supply air (drop of 51%) What happens to air velocity at the register? EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Consider the Following Situation Home contains 15 registers. Each register is 4” x 12” in size. Each register has 75% effectively open area. What is the Velocity vs. Supply Temperature? EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Observations For the same heat load to the home, the amount of register air velocity changes from 652 CFM at 90F supply air temperature to 316 CFM at 120F supply air temperature. Compare with real world delivered air temperatures. EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004© Typical For Heat Pump Typical For Warm Air Furnace Body Temp. EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

Implications EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004© Lower temp. air supply systems like heat pumps supply air at temperatures less than body temperature – feels cold. Lower temp. air supply systems like heat pumps must deliver more air (i.e., higher velocity air to provide the same amount of heat). Higher temp. air supply systems like warm air furnaces supply air at temperatures above the body temperature and at lower velocities. New higher efficiency equipment (both gas and electric) will supply air at lower temperatures and higher velocities – Implies that efficiency does not correlate with comfort! EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

THANK YOU ANY QUESTIONS? EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©

E E Thank You S EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004© Stephen E. Petty, P.E., C.I.H. 84 N. High Street, Suite 2B Dublin, OH 43017 Phone: (614) 798-4123 Fax: (614) 798-4118 www.eesinc.cc EES ENERGY & ENVIRONMENTAL SOLUTIONS, INC. 2004©