Energy-saving deadline for circulators is nigh
EU legislation aimed at halving the energy used by glandless circulating pumps by 2020 amounts to the output of six medium-sized coal-fired power stations, reducing CO2 emissions by about 11 Mt a year. Gary Wheatley of Wilo has the details.
2013 will see the start of a pumping revolution. And it’s every bit as important as that statement sounds. The European Union has recognised that to achieve anywhere near its requirements for reducing carbon emissions and to see significant reductions in the energy needed to power heating and hot-water systems across the 27 member states, it has to lay down the law.
The UK Government has set out very ambitious targets for energy and carbon reduction and is looking for significant help from the heating and hot water and air conditioning sectors to achieve them. Having addressed the issues relating to the energy efficiency of boilers and begun the process of encouraging the introduction of renewables on a wider scale, albeit perhaps a little half-heartedly due to the economic constraints, the UK has had to adjust to of late, the Government has had to turn its attention to other components of the heating system to find other sources of savings that will make a healthy contribution to the totals required to make a dent in the targets with which it is faced.
Clearly one of the key components of a heating or cooling system that currently uses too much energy — although quite small in size and overlooked by many as a key user of electricity — is the pump.
The total electricity consumption of all glandless circulating pumps operated in the European Union for heating and air conditioning — the normal small circulating pumps — has to be halved by 2020. This is the objective of an EU ordinance under the European ErP (Eco-Design) Directive which will regulate the energy efficiency of this type of pump, from 1 January 2013 onwards, with a further tightening of requirements planned for 1 August 2015.
Overall, these changes are thought to be likely to provide an energy saving of 23 TWh [1 TWh, terawatt hour, is 1000 GWh] for the EU as a whole. This corresponds to the electricity generated by about six medium-sized coal-fired power stations or a reduction in EU-wide carbon dioxide (CO2) emissions of about 11 Mt per year.
To achieve this goal set by the European Commission, the EU ordinance prohibits the sale of technically outmoded, inefficient pump models from 2013 onwards. This will mean a ban on sales of about 90% of the glandless circulating pumps that were on the market in 2009. The reality is that the new efficiency requirements will be practically impossible to achieve without using high-efficiency pumps with EC motor technology.
The important new yardstick for determining which pump models can continue to be used in future is referred to as the energy efficiency index (EEI). This is calculated using a process defined in the ordinance — (EC) 641/2009. The average electrical power of a pump is calculated on the basis of a load profile in relation to a reference pump, that is, an average pump with the same hydraulic output.
|Wilo’s Stratos PICO pump could reduce electricity consumption by up to 90% compared to standard pumps without speed control.|
From January 2013, the limit EEI value of glandless circulating pumps installed outside the heat generator (external pumps) will be defined as 0.27. The energy-efficiency classes currently specified will then become superfluous because, as a rule, pumps will be better than the minimum requirements of the current A-rated pumps.
From August 2015, the EEI limit value will be reduced to 0.23. This will also apply to glandless circulation pumps designed to operate in newly installed heat generators or solar-thermal systems (integrated pumps).
In the last implementation stage, the regulations starting from 2020 will also apply to the replacement of integrated pumps in existing heat generators. The regulations apply to all glandless circulating pumps in heating and air-conditioning applications, with the exception of drinking-water circulation pumps.
Looking at the current pump population, there are still many heating and air-conditioning systems with fixed-speed pumps using up to 10 times more electricity than the newest pump generation requires. Models with extremely low electricity consumption are already available from many manufacturers, including Wilo.
The two main technology changes which influence the energy savings available are the move away from standard induction motors to permanent-magnet motors and the move from standard-speed technology to variable-speed technology.
Wilo’s Stratos and Stratos PICO series of single pumps, for example, offer potential electricity savings of up to 90% compared to standard pumps without speed control. They already comply with the limit values of the second stage of the glandless circulating pump ordinance due for 2015 and are already prepared for the future, without any restrictions.
These electronically controlled glandless circulation pumps have maintenance-free frequency converters that automatically adjust to the changing operating status of the heating system. Especially in the partial-load range, which makes up as much as 94% of the operating time of a heating pump, a considerable reduction in power consumption can be achieved compared to an uncontrolled pump. In addition, they have what are known as electronically commutated (EC) motors that make it possible to double efficiency compared to electronically controlled pumps with conventional drives.
Gary Wheatley is technical manager with Wilo UK.