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Air conditioning: the ecological approach

“Green” refrigerating fluids, energy savings: air conditioning has been overcome by a green wave. Often under fire because of their use of electricity, systems are becoming more efficient and eco-friendly.

Air-conditioned restaurants, and cool rooms: the comfort of guests in the summertime comes with a cost. While the cost remains high, both in terms of initial investment and energy consumption, hoteliers cannot get around buying into an efficient air conditioning system. “Commercially, it isn’t possible anymore,” observes Philippe Mongreville, CEO of the company Atmosph’Air. This expected service is no longer just a sales pitch, it can even assume a defensive aspect. While the upscale and midscale have long been converts, the economy segment adopted it more recently. The heat wave of 2003 acted as a reminder of how important having air conditioning or a less costly air-cooling system is for avoiding seeing hotel guests run off with the competition. The movement is widespread: commercial restaurants have adopted it and, in the hotel industry, in the wake of major brands such as Etap Hotel or B&B, the 0-1* are quick to display signs on their roofs boasting “Air conditioned”, to reassure clients.Regular maintenance of air conditioning systems is primordial. A dirty device means lower airflow and higher energy consumption. Regular cleaning of filters in each unit as well as maintenance of batteries in outside units guarantees optimal performance. Carrying out maintenance on an installation guarantees not only the best efficiency but is also important in terms of hygiene. In fact, the collecting bin for water condensation requires proper attention to prevent the propagation of disease. “All air conditioners produce water. But stagnant water with cool air blowing across it is propitious to bacterial propagation and must therefore be treated regularly with bactericidal products,” remarks Philippe Mongreville. Atmosph'Air thus recommends two to four maintenance visits yearly – before the high and peak seasons – and even more often in polluted city centers.But since investment is costly, hoteliers must be careful about all the details. Quality, durability and reliability are the three pillars of successful air conditioning. At a time when cheap cooling systems are invading the market, it is still preferable to opt for well-known manufacturers, and for installation to trust companies that frequently work with the hotel industry. With integrated teams and confidence, they know how to work at an occupied worksite. “It is our obligation to work with short deadlines and under the constraint of returning a fully operable room when our work is finished. This means no drilling before 10am and leaving the space clean at 5pm,” explains Philippe Mongreville.When choosing, several elements must be verified in order for the air conditioning system to be in line with the property’s needs and its economic model: low energy consumption, an installation enabling easy maintenance and, of course, optimal acoustic comfort to avoid disturbing clientele. Another major alternative must also be considered: water vector or refrigerating fluid? Today, from an energy and acoustic perspective, direct expansion refrigeration systems using a refrigerating fluid has gained ground on chilled water, which is now used mostly by big industrial structures and very tall buildings. Less cumbersome, split technology uses tubes with smaller diameters making their installation possible in more complex settings. Another advantage: zero risk of Legionnaire’s disease, which develops in stagnant water between 25° and 40° Celsius.Although it is often more expensive to install than chilled water technology, it costs less to operate and maintain. Moreover, direct expansion refrigeration systems are reversible, making it possible for it to do double duty thanks to a heat pump system: thermodynamic heating in the winter or cooling in the summer. This makes substantial energy savings possible. The top of the line in this regard is the VRF system (Variable Refrigerant Flow), which is exclusive to licensed Asian brands such as Daikin or Mitsubishi. This technology optimizes the split system which makes it possible to condition a high number of units (more than 50 rooms for a hotel). It exists in two versions. The two-tube VRF system, less flexible, produces either heat or cold. The three-tube VRF system allows use on-demand. “Between seasons, the client may need to heat in the morning and to cool during the day,” explains the CEO at Atmosph’Air.Thanks to the VRF system, in addition to greater acoustic comfort, the hotelier may adapt the volume of refrigerant in function of his property’s needs by adapting production to occupancy. These systems may be coupled with a control center that allows the hotelier to set the level of air conditioning in each room by establishing minimum and maximum temperatures – 20°C minimum in the summer and 25°C maximum in the winter for example – or by setting an economy mode during the daytime.These technological advancements combine with requirements to reduce energy bills for both economic and environmental reasons. “Japanese manufacturers have launched the COP -coefficient of performance-– battle,” observes Philippe Mongreville. The best air conditioning systems have a COP of 5 – meaning restitution of energy 5 times higher than the energy absorbed – while bad ones fall between 3 and 3.5. Among the most efficient systems, is the Zubadan model launched by Mitsubishi last year. Even when the temperature outdoors is negative, the heat pump suffers no loss of power. This allows the system to maintain a high COP even when it is extremely cold.Air conditioning has long been singled out for its consumption and important use of gases with a greenhouse effect. Regulations thus became more drastic. From 2004, the production of systems using the fluid R22 – better known as Freon – was banned. And in just a few months, in 2010, it will also be forbidden to recharge systems that use this gas , except for the use of recycled R22 which will be authorized until 2015. “But a word of caution: recycled R22 may be stocked for no more than 5 to 6 months. The slightest problem means recharging the system and cannot be guaranteed,” warns Atmosph’Air’s CEO.Hoteliers who have not planned on this transition could find themselves highly unprepared if there is a leak. To replace R22, hoteliers will have to shift to systems using a “green” fluid: R410A. This will require new equipment. In the best of cases this means changing each unit and the outside unit and, in certain cases, all new piping. The transition towards eco-friendly air conditioning has begun. While R410A is “ozone friendly”, this fluid is not the panacea. Its GWP (Global Warming Potential) is 1730 meaning the equivalent of 1730 kilos of CO2. According to Ademe (French agency for environment and energy control), effort still needs to be made in order to make air conditioning systems that are truly ecological. Should we expect stricter legislation in the years to come?For the hotelier who wants to completely avoid this issue, a 100% natural cooling system is available. Controlled air fanning using a noiseless, low energy consumption motor with a lifetime guarantee: the ceiling fan fits perfectly into a sustainable approach. While not as powerful as traditional air conditioning, the fan effect offers the guest wellbeing. And in the winter, reversing the direction of the blades pushes heat back down. Thus, in a space where there is a fireplace, a fan makes it possible to gain 2 to 4°. And 1 degree gained in the winter represents 6% of the heating bill.Contrary to air conditioning systems – although manufacturers are trying to work on their aesthetics – ceiling fans fit into spaces very well. “The ceiling fan can be an architectural centerpiece, the way a chandelier can,” promotes Claude Pichegru, manager of Guibb, the official distributor of American Hunter fans. In order to adapt to all designs, this company offers 80 models. “Today we are seeing colors such as anthracite, old brick or new bronze”. The best sellers are Savoy for the classic range, Tribeca for the design range and Carrera for the modern range which present the same characteristics: a capacity to mix 13,500 m3/h, a diameter of 1.32 m and 85 watt power. Energy consumption is 1 euro per two weeks operation 24 hours a day. With all these advantages, in the eyes of the United States where this product has gained favor, Europe offers a wide growth margin for ceiling fans with just 2 million fans sold each year versus 17 in the United States.Avoiding breakdowns and disease: opt for maintenance Regular maintenance of air conditioning systems is primordial. A dirty device means lower airflow and higher energy consumption. Regular cleaning of filters in each unit as well as maintenance of batteries in outside units guarantees optimal performance. Carrying out maintenance on an installation guarantees not only the best efficiency but is also important in terms of hygiene. In fact, the collecting bin for water condensation requires proper attention to prevent the propagation of disease. “All air conditioners produce water. But stagnant water with cool air blowing across it is propitious to bacterial propagation and must therefore be treated regularly with bactericidal products,” remarks Philippe Mongreville. Atmosph'Air thus recommends two to four maintenance visits yearly – before the high and peak seasons – and even more often in polluted city centers.

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