Are you looking for new air-conditioning units for your home or office? Well, buying a new piece of air-conditioning system is not so easy, unless you have a certain goal in mind. The basic specifications one often has in mind are the day-to-day running costs and the level of energy efficiency your new equipment will offer you. Buying the most efficient air-conditioning system will benefit you later through lower operating costs.

The first and foremost aspect to consider while purchasing new air conditioning systems is to choose one with the most appropriate and effective cooling facility for your requirements. Make sure it offers you the required level of energy efficiency for both the design as well as installation charges right from the beginning. You must implement a control system for your new equipment and execute effective commissioning of your new air conditioning systems. If possible, create a maintenance plan or employ a maintenance contractor to keep you updated with the operation of the system at regular intervals after its installation. It is also advisable to provide appropriate training to your system users.

Three generic kinds of air-conditioning systems have evolved in response to the new directives issued by the UK government with regards to the excessive energy consumption by conventional buildings and carbon dioxide emissions. These systems are known to as centralised air systems, partially centralised air/water systems and local systems. Under centralised air systems, all heating and cooling process takes place in a central plant room and are then transmitted to the rooms through the ductwork system. A partially centralised air/water system involves the heating and cooling of air upon entry to the rooms, while in local systems, all operations are conducted locally.

Centralised air-conditioning systems supply cooling from large central chillers generating cold water, which is then pumped around the building wherever it is required through the pipe system. These systems are basically implemented around a packaged Air Handling Unit (or AHU). The AHU contains heating and cooling coils, filter, a humidifier and a fan for air movement. The incoming air is put into the AHU and then transmitted to the coils for heating or cooling the air as and when required. The conditioned air is then supplied to the rooms through the ductwork system inside the building. The cooling equipment is roof-mounted and put in central plant rooms. The refrigeration equipment or the chillers supply chilled water for the cooling coils in the AHU. The chiller may be cooled by a cooling tower or alternatively through outside air. Boilers placed in another plant room are used to heat water for heating coils. Air ducts can also be used for transferring heating and cooling to occupied spaces. Pipes are generally used to supply heated and cooled water to terminal units in all rooms.

If the external air is cooler than the internal temperature, the external air can be transmitted inside the building without having to use chillers. UK temperatures often go below 19 degree Celsius, which can be utilised as free cooling and refrigeration is not required. Centralised air systems are available in different modes, viz. Constant Volume (CV), Variable Air Volume (VAV) and Displacement Ventilation, promising efficient energy systems and occupancy comfort.

When the diversion to electricity was advocated by the UK Government, the electricity consumption in the country increased by 150% during the period 1948-mid 1960s. But later during the 1960s, the growth declined due to market saturation. During 2004, the total energy consumption in the UK was 161.1 million tonnes of oil, that is, 67.6% of the total energy.

During early 2000, there grew a fear of an energy gap in the country’s electricity generation capacity. It is anticipated that various coal fired power stations will shut down on account of its irresponsibility in cleaning the air requirements as per the European Large Combustion Plant Directive. The year 2015 will see the closing down of the four remaining Magnox nuclear stations and four of the AGR nuclear stations in the UK. The oldest of the seven AGR nuclear stations has had its life recently extended by ten years.

As per the industry reports (2005), there might be a shortfall of 20% in electricity generating capacity by 2015. There has also been a solution encouraged to construct new generation nuclear power stations that emit less carbon dioxide. The UK Government is also required to work strategically towards filling the energy gap in the country and exploring alternative power generation technologies so that the carbon dioxide emissions can be reduced substantially.

In June 2006, Centrica announced the construction of Langage Power Station, a conventionally gas-fired power station. Later in 2007, two new coal-fired power stations were announced for Tilbury (Essex) and Kingsnorth (Kent) in the UK, the first time a coal-fired power station would be constructed in the country for 20 years. Apart from these plants, other options suggested to provide new electricity generation capacity and reduce carbon emissions include fossil fuel power plants, nuclear power plants, offshore wind farms, wave power and tidal power, combined heat and power plants, gas from sewage and landfill (biogas), solar electricity, geothermal power, micro generation and sustainable community energy systems.

Is your building working at the correct energy efficiency levels or performing optimally? The air-conditioning system in a commercial building, as per the new ruling of the UK Government, should be well-maintained and operated so that it provides a safe and comfortable work environment and delivers maximum productivity. Nevertheless, very few newly-built buildings have been able to achieve a satisfactory level of performance and productivity because the systems have not been installed in correct order.

The most important aspect to consider for an existing building is to examine if the building has been designed to work in conjunction with the environmental conditions. The existing conditions of the building and the performance of the existing cooling systems should be assessed properly. The building and its systems should be well-documented in a language and format for the managers to understand with ease. Every problematic area should be well analysed and addressed for appropriate solutions. The internal work conditions should be adhered to at regular intervals so that nothing is left unturned to bring improvements in productivity and efficiency levels.

Building operations should be reviewed regularly and frequently to identify the areas where there is a need to evaluate the building controls and services, or replace the plant or equipment. Both plant and equipment should be regularly maintained and checked for wear and tear and its maintenance charges. Log books and records should be retained to determine the need for new and more efficient plant systems. Commissioning activities including control settings and re-balancing of air flows should be undertaken to integrate good performance and cut down the operational expenditure.

Do you know if the energy use of air-conditioning systems within your building is effective? Do you want to bring the energy usage to an optimum level? There can be numerous factors that should be taken into account while gauging the energy use of an air-conditioning unit.

Firstly, you need to analyse the design, layout and operational level of your building. This has a direct impact on the external environment influencing the internal environment in terms of temperatures and humidity. The internal temperature inside the building should be cooler with greater precision, while the air quality should be more refined. Secondly, the heat added to the building through lighting and equipment determines the cooling temperature required to be maintained inside the building.

Besides, you must be aware that the design and efficiency of air-conditioning systems in the building also plays a key role in providing control over cooling and moisture systems required in different internal areas of the building. Estimate the need for cooling systems by keeping a check on the air-conditioning equipments and the control systems. This will also assist you in reducing energy consumption, make more savings and provide a comfortable and healthy environment for your staff for working.

Buildings with optimum energy efficiency levels are more cost-effective as compared to conventional buildings.

Fully air-conditioned buildings can be checked for performance levels on the basis of three parameters, i.e. good design, suitable commissioning and effective maintenance of equipment and building. Today however, many commercial buildings with complex service systems lag behind in terms of occupancy and operational costs level. Only a few commercial buildings have been performing well with their simpler and free cooling systems, and reduced cost energy levels.

It is high time for building operators to start working on their existing air-conditioning systems to reduce carbon dioxide emissions and work aggressively on more energy savings. To start with, building fabrics could be improvised. Buildings operating with good insulation can help with heat savings and cooling expenditure. Any gaps in the fabric can let the heated or cooled air escape resulting in wasted energy and money. Therefore, the building fabric should be improved as well as replacing the existing air-conditioning system. Any gaps or holes in walls, doors, windows and skylights should be identified and targeted for immediate repairs.

Many commercial buildings are facing the problem of high levels of glazing due to overheating. To prevent this, it is recommended that fixed or moveable external shading for windows should be implemented, or window panes can also be replaced with special heat-reflective glass for the cause.

The basic control over existing cooling systems can be maintained by setting appropriate internal cooling temperatures inside every portion of the building. People normally feel comfortable in a temperature ranging from 18-26 degree Celsius, as per the climate conditions. Ideally, an office is not set over 3 degree Celsius below the external temperature. Therefore, the internal temperature should be set in for cooling in sync with the external temperature. Additionally, the internal staff should be dressed such that it goes well with the extreme environmental conditions, and must also be provided with appropriate guidance on operating temperatures and setting heating or cooling units properly. Louvres, for instance, is an important feature of air-conditioning system that guides the cooling or heating of air, and so training should be given to the staff so they can operate them properly.

Soon after the F-gas Regulation was passed, the phase out of R22 refrigerant has gained a speedy momentum in the commercial industry. A majority of manufacturers in commercial and industrial units have stopped using R-22 refrigerant and have moved to Hydro-Fluoro Carbons (HFCs) in its replacement. R-410, in particular, is increasing becoming a popular ingredient as an alternative to R-22 amongst various commercial manufacturers. Nevertheless, the commercial air-conditioning sector then was moving towards R-410 A for their equipments at a slower pace. Not more than 10 percent of the manufacturers were installing this equipment in the year 2007. In 2008, however, this number is predicted to amplify into 20 percent and up to 50 percent in 2009, especially in the residential equipments application.

As per the market analysts and the regulatory issues, no manufacturer will be allowed to make any unit with R-22 as its refrigerant with effect from January 01, 2010, whether it is in residential or commercial units. It is also expected that the market will fall short of R-22 units in the upcoming years, or especially that period, when the wholesalers might already had kept a stock of older units, and contractors will be found howling to work with the fading products.

A steady move towards R-410A at the end of 2009 would also result into a dearth in the supply of the equipment and there also won’t be enough supplies of R-22 for the service sector in the years to come, adds Powell. Therefore, it is imperative to promote awareness and educate people about the need of the hour to use only those equipments that run on HFCs, and help them understand the potential causes related thereon.

According to the Emerson survey in May 2007, it was found that 13 percent of contractors are offering only R-410A units to their clients, while 69 percent are quoting both R-22 and R-410A to their customers. 65 percent of the contractors were believed to have been training their technicians in working on R-410A, whereas, 57 percent of service vans now possess necessary tools and equipments to install and develop R-410A equipments.

The September 2007 Meeting of the Parties to the Montreal Protocol (MOP-19) exemplified a firm control over the supplies of HCFC-22 and the usage of the refrigerant R22. One of the important aspects of the agreement was that the R-22 can be continued to be used in the existing plant systems, or may be in the existing final phase out of its new production by the year 2020. However, these production units need to reduce the amount of manufacturing and supplies of these hazardous components and if any such production is already under progress, it needs to be produced faster in pace than its previous speed required. For instance, as per the previous regulations, the manufacturing of R-22 had to be diminished by the year 2010 by 65 percent from its base production in the year 1989. Nevertheless, this amount of deduction has now been increased to 75 percent from 65 percent in accordance with the new rulings.

As per the industry experts, this aggressive reduction can further result into a major negative impact on the aftermarket supplies of R-22, and so, more recovery and reclamation efforts need to be embarked upon. For example, industry experts predict that 2015 will be the crossover year that will witness shortage of supplies of R-22 in response to its demand. A few experts foresee years ahead of 2015 might face this kind of a situation.

In spite of the above, the target date set by the ruling UK Government still remains 2010, when all the industrial as well as commercial units will be banned from continuing with the usage of R-22 in their existing plants as well as any new plants. They are, therefore, advised to seek for a back-up plan, or consider good alternatives to replace their refrigerants to avoid any future problems.

Today, a majority of R-22 is being replaced by the alternative HFC. HFCs offer useful properties such as zero toxicity but with a high GWP. With the new regulation on place, the usage and ban of harmful refrigerants have been implemented until 2010. The new F-Gas Regulation suggest that there should be no ban on the usage of HFCs, except in air-conditioning of cars, that is, no car shall be allowed to make use of HFCs in their air-conditioning systems.

The most recently used alternative is R-410A. It is operated at higher pressures and has high cooling capacity with good heat transfer characteristics. R-410A has a high GWP and its design is mostly compatible with systems with higher head pressures. This refrigerant has been introduced into several equipments used for residential equipments at slow pace, and now, it is also being applied at commercial units for their existing plant systems.

As per the recent survey conducted by Emerson Climate Technologies in May 2007 involving in excess of 500 contractors and distributors, it was pronounced by Brandy Powell, Marketing Director for Air Conditioning business that around 23 to 26 percent of residential air-conditioning equipments that is being manufactured and installed run on R-410A. The figure was 20 percent in the year 2006, and is further expected to rise in 2008 by 35 percent and 55 percent in 2009.

However, the new ruling enforced on the usage and ban of HFCs also requires the industrial and commercial units and the end users to avoid the usage of HFCs to the maximum to improvise the cost structure and bring about safety. A few key alternatives to HFCs can be using Ammonia in large industrial enterprises as well as for air-conditioning chillers, use of Carbon Dioxide (CO2) for industrial purposes, supermarkets and air-conditioning. Hydrocarbons can be used only for small systems.

Today, almost every person who seems closely attached with refrigerants is now encouraging contractors to install and make use of leak-free equipments and maintain them during servicing. Some are even urging contractors to exhibit the real use of refrigerants, which must include the correct recovery and recycling procedures with strong recuperative efforts. To give this a successful implementation, a majority of wholesalers and manufacturers are seeking different methods to bring about a proper and effective recovery chain and better reward contractors who can later bring refrigerants for reclamation. Industry experts say that instead of speeding up the phase out of old refrigerants, the real market driver to bring about changes and new directions in refrigerants would only come if the manufacturers undertake proper reclamation efforts for their existing refrigerants.

Industry analysts suggest energy efficiency, applications, safety and environmental regulations as the foremost market drivers towards the paradigm shift in the usage of refrigerants. The Montreal protocol signed by the United States some 20 years ago emphasized the protection of ozone layer from its depletion by eradicating the production of the harmful substances responsible for the same, particularly CFCs and HFCs in the HVACR industry. Later, the Kyoto Protocol enacted measures to address global warming issues, targeting the HFCs again. However, the US Government never pay a heed to the Kyoto ruling due to issues that held developed countries such as the United States and Canada as of higher standard as compared to developing countries such as India and China, to impose these regulations upon. Presently, Kyoto is taking a legal approach to move into the United States. Various climate change proposals have been developed in Congress to control the production of HFCs in the States, thus levelling up with the Kyoto Protocol after 2020.

Keeping other things equal, it can be concluded that contractors are sooner going to put their refrigerants, be it old or new ones, to proper use, as they are increasingly becoming the most precious commodities today, the shortage in the supply of which can be easily foreseen in the future.