Energy efficient entrances to buildings can be achieved by correctly fitting and maintaining an effective air barrier. CIBSE approved CPD presentations available to consultants and architects.
2. Air Curtain Fundamentals * Usually mounted over doorway, alternatively at sides * Reduces outside air entering building * Creates a warm air stream * Reduces mixing of inside / outside climates * Energy saving device * Improves internal environment * Can be installed in different applications
3. Air Curtain Fundamentals * Usually mounted over doorway, alternatively at sides * Reduces outside air entering building * Creates a warm air stream * Reduces mixing of inside / outside climates * Energy saving device * Improves internal environment * Can be installed in different applications
4. Air Curtain Fundamentals * Usually mounted over doorway, alternatively at sides * Reduces outside air entering building * Creates a warm air stream * Reduces mixing of inside / outside climates * Energy saving device * Improves internal environment * Can be installed in different applications
5. Air Curtain Fundamentals * Usually mounted over doorway, alternatively at sides * Reduces outside air entering building * Creates a warm air stream * Reduces mixing of inside / outside climates * Energy saving device * Improves internal environment * Can be installed in different applications
6. Air Curtain Science * Most efficient leaving air velocity 6.5~7.5 m/s * Optimum leaving air temperature 36~38ºC. * Achieve laminar flow of air stream * Designed to work with ambient air temperature of between 16~20ºC * Not a barrier, the air stream tempers incoming infiltration * Can be used throughout Summer & Winter
7. Factors Affecting Air Curtain Performance * Building design * Building leakage / extract rates * Surrounding geography * Prevailing weather conditions * Installation of air curtain * Leaving air temperature/velocity * Method of control
8. Factors Affecting Air Curtain Performance * Building design * Building leakage / extract rates * Surrounding geography * Prevailing weather conditions * Installation of air curtain * Leaving air temperature/velocity * Method of control
9. Air Curtain Pitfalls * Installed too high. * Leaving air temperature too low * Not covering full width of door * Used as a primary heat source * Leaving air temperature too high * Inadequate method of control * Incorrectly installed (i.e. too far away from door opening)
10. Correct Installation * Cover full width of door opening * Outlet grille as close as possible to top of door * Install within correct mounting height * Controls method * Consider aesthetics / environment * Units can be mounted vertically and horizontally Air curtain not covering full width, air bypass at sides Plan view showing cold air bypass at sides
11. Scenarios * Air Curtain Operating Building leakage 5m3/h/m2 Minimal infiltration Good climate separation * Air Curtain Operating Building leakage rate increased 20m3/h/m2 Infiltration is at slightly higher level. Climates still well separated * Air Curtain Switched Off Building leakage rate 20m3/h/m2 Infiltration rate high, cold spots around doorway. Climates mixing, thus entrance cooling. Temperature profile very uneven
12. BSRIA Study Findings (BSRIA report 77710/1) * Correct installation is vital. * Outlet grille design is important. * Building design affects the performance. * Building leakage greatly affects performance. * Too high leaving temperature affects air stream. * If outside air entering the door way exceeds 3m/s (13 MPH) the warm air stream begins to breaks down.
13. Controls * Manual / stand alone operation * Interface with building management systems * Door switch / time clocks * Thermostatic control * External sensors * Intelligent controllers ~ latest technology
14. “Enetec” Energy Saving Controller * Enetec intelligent controller (tested by BSRIA) * Monitors external and internal temperature, modulates heat output * Heater output regulated proportionally, instead of staging * Savings of between 30 & 60% have been recorded. (compared to standard air curtain control) * Units can be linked in master / slave scenario * Links into BMS
15. Conclusions * Take into account influencing factors * Size units correctly * Consider control options * Ensure correct installation. * Do not be influenced by others