Condensing technology can aid compliance

The introduction of the CRC Energy Efficiency Scheme earlier this year has made it even more important for organisations to look at their carbon emissions and find ways to reduce them. In addition to complying with the legislation, businesses will also find they save money by becoming more energy efficient.

The CRC Energy Efficiency scheme (originally called the Carbon Reduction Commitment) was introduced in April 2010 and requires certain organisations to assess how much energy, from all fuel sources, they are likely to consume in the forthcoming year. They will then have to purchase a carbon allowance, and if the company uses more than this, they will be charged a penalty. Those which use less will be given a bonus.

The scheme encompasses many large UK organisations, as well as the public sector, with approximately 5,000 organisations being affected. The overall aim of the scheme is to reduce carbon emissions and companies need to register by October 2010, but would be advised to look at ways to reduce their carbon emissions now. This will not only help them comply, but will also save them money on their energy bills.

Efficient solution

While hot water generation may not have the biggest impact on carbon emissions, looking for a more energy efficient solution will certainly ensure reductions are achieved. Solar thermal technology has so far proved to be the most popular LZC technology, which some businesses and organisations have embraced as a way to lower emissions and cut costs. Solar is a relatively simple solution for organisations to implement, and from a heating engineer’s point of view, it is fairly easy to integrate a solar system in conjunction with a conventional water heater.

An additional benefit of solar technology is that it is highly suitable for retrofit projects as well as new builds. In light of the recent budget announcements by the Government, new build projects are likely to continue declining. For this reason, companies and organisations are more likely to find ways to improve existing buildings, and solar can be introduced relatively simply when compared to other renewable technologies.

While solar thermal clearly has many benefits, it is important to remember it will only usually provide a maximum of 25 to 30% of the annual hot water requirement for commercial buildings. To supplement the hot water generated by solar, one of the most effective ways is to use direct gas fired water heaters. The hot water from solar gain will be used to provide pre-heated feed water to the gas-fired water heater installation. As the largest proportion of a building’s hot water demand will therefore be generated via the traditional method rather than the solar technology itself, the correct selection of this primary source of hot water is equally, if not more, important than the solar gain proportion.

The use of twin coil cylinders is commonplace in residential dwellings, with the lower coil being used to transfer the solar gain, and the upper coil being supplied with hot water via the buildings central heating boiler. However, the effect of the solar gain is reduced by the indirect coil from the heating boiler and furthermore, this indirect method of generating hot water is not as efficient as a direct, gas-fired water heater.

If you take this into account when specifying for a commercial application, there is clearly a strong argument for using gas-fired water heaters in conjunction with solar thermal systems. Based upon the principles of low storage but fast recovery of hot water, this technology therefore uses fuel more efficiently than an indirect system. This concept has been utilised for more than 30 years, and currently most water heater manufacturers now use condensing technologies. The operating efficiencies of this equipment can reach as high as 98% based upon gross CV.

Reduce emissions

Air source heat pumps provide another renewable option and, as with solar it can be relatively easy to install on existing buildings. It will certainly be one technology that companies consider introducing to reduce carbon emissions and help compliance with the CRC Energy Efficiency Scheme. Looking again to retrofit applications, installation of an air source heat pump is relatively straightforward and can provide a fairly good return on investment. As with solar, the heat pump will provide pre-heated water to a gas-fired water heater, which will be the primary method of generating hot water in commercial settings.

In addition to choosing the most suitable technology, when looking to specify new equipment for a retrofit project, an important consideration is the amount of space available. Manufacturers recognise that every project is different, and therefore provide a wide range of equipment to suit all needs. For example, Lochinvar offers an extensive choice of gas-fired water heaters including the EcoForce range, which include floor standing and wall hung models. This provides options in terms of the best siting of the water heater and such options can be particularly beneficial when space is at a premium.

Renewable hot water generation technologies will clearly play a role in compliance with the CRC Energy Efficiency Scheme, but building owners and occupiers should also remember the importance of the primary equipment. Condensing gas-fired water heaters offer high operating efficiencies and can be integrated with renewable technologies relatively easily. As such, they are ideal for projects where carbon emissions need to be reduced, and this is where the technology has a role in helping companies to comply with legislation.

Going green

Lochinvar recently provided an air source heat pump and gas-fired water heater to the Great Western Arms pub and restaurant at Aynho near Banbury. A refurbishment of the property included the conversion of some disused space into four guest bedrooms and as part of the project, the heating and hot water systems were upgraded.

In a bid to become more energy efficient, the brewery opted for an air source heat pump, combined with a Lochinvar EcoForce gas fired condensing water heater. This LZC package provided a greener system for the brewery, while offering reliable and efficient hot water generation.

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