Water heating Keeping E
ver since the introduction of the initial batch of ErP Directive requirements, manufacturers have been continuously working on meeting (if not exceeding) those. While the energy label might seem familiar as it comes
directly with a product, it is only applied to lower output water heaters ≤70kW and hot water storage tanks ≤500 litres. However, the wider scope concerns the Ecodesign requirements which affect water heaters with an output of ≤400kW and storage volumes of ≤2,000 litres – a large part of the commercial sector. These are general product design requirements regarding water heating energy efficiency, storage volume, nitrogen oxide levels, and standby losses etc.
Load profiles and energy efficiency requirements
To determine the energy efficiency level of water heaters, they are divided into different “load profiles”. These range from 3XS to 4XL and are based on a given sequence of water draw-offs in a 24-hour cycle that the water heater can provide. Every water heater meets at least one, but the declared profile is either the maximum or one below the maximum load profile. On 26 September 2015, we saw the introduction of Tier 1 of the minimum energy efficiency requirements for water heaters. Also enforced were maximum
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water heaters compliant
In September this year, manufacturers are facing the introduction of more stringent rules for water heaters stemming from the ErP Directive. The aim of these rules? To help achieve carbon reductions of 20% compared to the 1990 baseline by 2020. Kevin Potter, business development manager for hot water solutions, Hamworthy Heating, examines what has happened since the first requirements were enforced in 2015 and what is to be expected from the future
storage volumes (only applies to 3XS – S maximum load profile water heaters) and minimum volumes of mixed water at 40°C (only applies to M – 4XL maximum load profile water heaters). For heat pump water heaters, maximum sound power levels became applicable. Energy labels for lower output models were introduced, with energy efficiency classes ranging from A to G. The enforcement of minimum energy efficiencies has been a welcome step
towards the reduction of CO2 emissions, thanks to lower gas use. Additionally, it has had a positive effect on energy bills. The application of energy labels has also allowed consumers for the first time to identify how efficient a new product is.
The shift in the market and impact on manufacturing
On 26 September last year, stricter energy efficiency requirements (Tier 2) were introduced. Additionally, standing loss limits for hot water storage tanks and solar water heaters became applicable. These are aimed at reducing energy wastage caused by heat being lost to the environment. Some manufacturers deliver their cylinders with thermal jackets to counteract this. To reflect the shift in products towards higher energy efficiency, the energy label was also updated to range from A+ to F, as products rated as “G” would not meet the requirements anymore. On 26 September this year, energy efficiency requirements will tighten again
(Tier 3). NOx emissions limits to combat air pollution will also be introduced. For conventional water heaters, the limits are 56 mg/kWh (gaseous fuels) and 120 mg/kWh (liquid fuels). What are the implications? Water heater models with NOx emissions
exceeding the limit and low maximum load profiles will be phased out. This will mostly affect atmospheric water heaters which can make like-for-like replacements difficult. It may be possible to supply water heaters not meeting the ErP requirements after 26th September, providing there are units already in the market (existing stock holding or through distribution) and only whilst stocks last. However, more efficient condensing water heaters will be the product of choice.
Dealing with condensate
A full flue system change is required when changing from an atmospheric to a condensing water heater to deal with the acidic condensate. If there is a bank of
38 April 2018
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