QAI (qualité de l´air intérieur) = IAQ (indoor air quality)
April 20, 2012, Rouen, France
Swegon Air Academy most recent seminar was held in a beautiful small chalet near Rouen and Moulineaux in Normandy, France. The very charismatic Susanne Deoux presented her research on health in buildings and the background of the hygiene in French building standards. Susanne´s presentation put high focus on indoor climate issues including sources of pollutants, health consequences, good indoor climate and sources of pollutions. Susanne also presented the effects of pollutions and ways how to limit the pollutions using a good ventilation strategy. Susanne described various techniques of getting the fresh air to the buildings such as ground loop heat exchanger with good measurement results of no radon contamination. Furthermore, Susanne talked about various types of lighting and their effects on health such as fluorescent or LED lighting.
In her presentation, Susanne focused greatly on why the indoor air is important part of the building design. The bad indoor air can cause respiratory problems in children´s development. Susanne showed some examples of concentration of various organic volatiles and biological pollutants such as COV, fibers or dust mites, among many others. Susanne also talked about the ways how to improve indoor air climate and different indoor climate assessment techniques.
Susanne´s engaging presentation was followed by the favourite Pascal Valladont who talked about the renovation of a former school into offices. Pascal focused more on technical aspects of renovation. He talked about the DHL´s headquarters located in Besançon; formerly an old school of 2,036 m2, it was renovated in 2005 with aim to reach 50 kWh/(m2.a) of final energy for HVAC use. The walls have been renovated with 100 mm of insulation from interior and another 120 mm of polystyrene on the exterior. The roof has 80 mm of rigid insulation plus another 260 mm of mineral wool insulation which results in U-value of 0.25 W/(m2.K). In summer, this mass of insulation delays the heat coming through the roof by 5-7 hours after employees have left the office. The aluminum framed windows are double glazed filled with argon (solar factor of 38%, high transmission of 70%, U = 2.0 W/(m2.K) with limited window surface area of 28% of the façade area.
To minimize energy consumption, the occupancy detectors were installed in all walkways and service areas, along with extra control of HVAC in meeting rooms. Distribution terminals are chilled beam modules operating at high temperatures in summer of 17°C and low temperature in winter of 35°C. The air is brought in through the rotary heat recovery unit (efficiency of 80%) with two fans with variable speed drive and coupled with air diffusers and chilled beams. Hygroscopic coating on the rotary heat exchangers enables latent recovery and humidifies new air in winter and dries it in the summer. Hot and cold water is produced by two glycol/water heat pumps with heating power of 32.6 kW and cooling power of 25.4 kW. Heat pumps are connected to 10 vertical geothermal bore holes (penetration depth of 100 m of each). This system supports the geo-cooling in summer and in winter water from the probes goes to the heat pump to produce heating.
The building is equipped with energy monitoring system and the result from the first year show heating & cooling needs of 55 kWh/(m2.a) and usage consumption of 57.6 kWh/(m2.a). The further refinement in second year led to the decrease of heating & cooling down to 49 kWh/(m2.a) and usage consumption of 50.1 kWh/(m2.a) where HVAC consumption accounting for less than 1/3 of this amount.
HDL wanted to show its clients how to master energy efficiency in the most credible possible way; leading by example.
On a personal note, I wish that there were more of these companies like this! Even though my language “incompatibility”, I have fully enjoyed the Swegon Air Academy seminar in French style in Normandy. I felt like I have met a very large French family of 23 people where all members came eager to learn more about health and energy in commercial buildings.
Photo by Susanne Deoux