Addressing the specification of circulating pumps can save a great deal of energy and money, says David Spragg.
The total electricity consumption of all glandless circulating pumps operated in the European Union for heating and air conditioning is 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 likely to provide an energy saving of 23 terawatt hours 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 emissions of about 11 million tonnes 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 per cent of the glandless circulating pumps that were on the market in 2009. In fact, the new efficiency requirements will be practically impossible to achieve without using high-efficiency pumps with EC motor technology.
The 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, i.e. an average pump with the same hydraulic output.
From January 2013, the limit EEI value of glandless circulating pumps installed outside the heat generator will be defined as 0.27. The energy efficiency classes specified at present will then become superfluous because, as a rule, pumps will be better than the minimum requirements of the current class A. 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 ac systems which are equipped with pumps that have no speed control. Because of this, an unnecessarily high amount of electricity is consumed - up to 10 times more than the newest pump generation requires.
Models with low electricity consumption are already available. These not only benefit the environment but also offer significant benefits to the building owner and the consumer because of lower electricity bills.
Wilo-Stratos and Wilo-Stratos PICO single pumps, for example, offers potential electricity savings of up to 90 per cent compared to standard pumps without speed control.
The electricity saving potential of up to 90 per cent offered by speedcontrolled pumps makes them so attractive to some customers that they are already swapping them for their old energy guzzlers in advance of the deadline, which is good for everyone.
• The author is head of residential sales, Wilo UK