Effective climate separation improves the energy efficiency of your building

The worldwide awareness towards energy efficiency and the need to reduce our carbon footprint play an important role in today’s building design. But why spending millions in isolating buildings and installing high energy efficient cooling equipment while at the same time a lot of energy is lost through the open doorway? By using the Biddle technology you do not only add comfort to your building climate, but also save substantially on your energy bill and reduce the excessive investment in cooling equipment. Biddle highly values the interest of the customer and environment by adapting its products and customer-specific advice to local conditions.

First, consider energy losses caused by convection forces. When two areas are connected by means of a door opening there usually is a temperature difference between these areas. The consequence of this ∆T is that inside and outside air start to mix; cold air moves to the warmer area via the bottom part of the opening and warm air penetrates into the building through the upper part. The energy losses caused by this effect of natural convection are often underestimated. A three by three meter door opening between a conditioned area of 20°C and an outside area of 40°C already causes a constant flow of energy of approximately 60kW. Together with this penetrating hot outside air, dust, insects, exhaust fumes and moisture from outside are also drawn into the building. The energy lost because of convection is even higher when the difference in relative humidity is taken into account. The entering latent heat including moisture requires easily five times more cooling capacity to be pumped away, meaning that the actual energy losses in this example are approximately 300kW.

High-efficient ambient air curtains considerably reduce the effect of moving air. Biddle understands that effective climate separation is more than just blowing air down a doorway. It starts with understanding the effect of convection and moving air. Fast blowing, cheap, simple and turbulent air curtains, which are widely applied now in the MENA region, often bring rather more negative than positive results. The speed is very critical for the performance of an air curtain and should be fast enough to bring the flow of air down to the ground but gentle enough not to collide with the floor. Another critical aspect is the level of turbulence of the air-flow. Due to Biddle's patented rectifier technology a non-turbulent air-flow at low velocity can be realised, which penetrates to the floor without mixing inside and outside air. The use of the rectifier technology results in real climate separation with over 90 percent efficiency and a comfortably cool indoor climate.

Without an air curtain, the incoming warm and humid air needs to be cooled down by the air conditioning units.  A high-efficient air curtain reduces the outflow of cold inside air to a minimum, which allows the air conditioner to operate at lower capacity. When climate separation is included in the energy calculations in an early design phase, a lower number of air conditioning units or units with lower cooling capacity need to be installed. Furthermore, an air conditioner blows out cool air only at a few spots in the room. An air curtain sucks this cool air and increases the recirculation effect, which means that large temperature differences are prevented and the comfort in the building is maintained at the desired level.

The prestigious Masdar City will be a 100 percent sustainable city in the UAE, making use of renewable energy sources and energy saving solutions. The designers of Masdar Institute of Science and Technology have understood well that an investment in real climate separation contributes substantially to their challenge to become the world's most ambitious eco-city. Biddle air curtains have recently been delivered to be installed above the entrances of this building in order to meet their challenging demands.

We would be most pleased to advise you how Biddle air curtains can reduce your energy bill and improve the comfort in your building.

Rob Schomaker is Director of Biddle Export Worldwide, a leader in innovative solutions in the field of climate separation in retail, public sector, cold and chill rooms. His background is electrical/mechanical engineering and through 20 years of experience in export his main skills are building long-term relationships with his key customers.