Presentation on theme: "Future Comforts: Policy Studies Institute Do you want to control the Temperature? Max Fordham."— Presentation transcript:
Future Comforts: Policy Studies Institute Do you want to control the Temperature? Max Fordham
We can provide control of temperature People have preferences Control of temperature uses fossil fuel! But... People are adaptable How much control do we need?
1 kW/m 2 Short Wave Radiation from the Sun RADIATION RESPIRATION EVAPORATION 35ºC 25ºC CONVECTION Wet Air Dry Air Heat Exchange of the Body with the Environment
BedfordAir temperature & Radiation UK, Early 20 th century WebbEquatorial Comfort Index: Wet bulb temperature= Enthalpy ASHRAEAir temperature, Humidity, Air speed. (Statistics), US, Mid 20 th century Belding & HatchAll Parameters, Simple Physics US, Mid 20 th century Ole FangerAll Parameters ISO Recent. Dusan FialaDevelop Fanger add involuntary reactions. Recent. ASHRAEConsider Voluntary Reactions. Comfort Research Summary
Comfort Conditions by Fanger Cold comfort boundary Hot comfort boundary
Singapore (28°C, 90% r.H.) Psychrometric Chart Saudi Arabia (46°C, 20% r.H.) Average UK Winter (10°C, 20% r.H.) 10 Room UK Winter (20°C, 10% r.H.) Specific Enthalpy [kJ/kg] Dry Bulb Temperature [°C] Moisture Content [g Water/kg Air] Air leaving Body (35°C, 100% r.H.) 14 Room Condition (25°C, 50% r.H.) Convection Evaporation
Otterbourne 30C not enough to open sash windows 43 Gloucester Crescent Is it really 30 C? Hong Kong Teaching 27C 56% RH radiant temp =air temp Light clothes: no adjustment wanted 20 building professionals Anecdotes QED
References Fordham S M. Building Physics - Reducing air conditoining needs in extreme climates. CIBSE Conference Climate change and its impact. Meteorological Office, Health & Safety Executive. EH 40/97 Occupational Exposure Limits 1997, Table 2 Page 22. (ISBN ). Total Carbon Cycle (tba). Nuclear Energy - the future climate. The Royal Society and The Royal Academy of Engineering, 1999 (ISBN ). Fanger P O. Olf and decipol: New units for preceived air quality. Building Services Engineering Research & Technology, Fiala D. Dynamische Simulation des menschlichen Wärmehaushalts und der thermischen Behaglichkeit. De Montfort University, Field Studies of Thermal Comfort and Adaption. ASHRAE Technical Data Bulletin, Volume 14, Number 1. January 1998.