Technologies

Heat pumps

The Energy Saving Trust's heat pump field trial is the most wide ranging monitoring exercise of domestic heat pump installations and customer feedback undertaken to date in the UK. The field trial was undertaken to determine the key factors which impact the performance of domestic-scale heat pumps, including technical parameters (e.g. system sizing and installation) and customer feedback and behaviour.

The trial was launched in July 2008 to monitor the performance of 83 air and ground source heat pumps installed in UK homes for a period of at least 12 months.

The findings illustrate that heat pump performance is highly dependent upon appropriate sizing, installation and integration with the building’s existing heating system, as well as appropriate control by the customer.

The field trial has been extended for a second year to undertake additional monitoring and evaluation of areas highlighted as requiring additional research. We expect to publish findings of ‘Phase 2’ in spring 2012.

The field trial was undertaken with funding and support from DECC, the Scottish Government, the UK’s energy suppliers, six heat pump manufacturers, and one specialist heat pump installer.

Download the full report Getting Warmer: a field trial of heat pumps

The Energy Saving Trust has developed comprehensive guidance for the installation and commissioning of ground source heat pumps (GSHP). This guidance is currently being reviewed with key members of the industry and will be re-launched in winter 2011 based upon conclusions gathered in the Energy Saving Trust field trial.

The Energy Saving Trust worked with technical experts in policymaking, academia, and industry to develop peer-reviewed methodologies to monitor the in-situ performance of heat pumps.

Download the heat pump monitoring specification

Solar thermal systems

The Energy Saving Trust's field trial of in-situ domestic STHW installations is the most wide ranging monitoring exercise of the technology and customer feedback undertaken to date in the UK. The trial was launched in Summer 2009 to monitor the performance of 90 installations in UK homes for a period of at least 12 months. The field trial has completed and the final public report will be available for download in autumn 2011. 

The field trial is being undertaken with funding and support from DECC, the Scottish Government, Welsh Assembly Government, the UK’s energy suppliers, Sustainable Energy Ireland, and a number of academic partners.

The Energy Saving Trust has developed LINK a comprehensive set of best practice guidelines LINK for the design, integration, and installation of solar thermal water hearing systems, including flat plate and evacuated tube installations. The protocol has been designed to provide guidance for installers, developers, and housing professionals.

The Energy Saving Trust worked with technical experts in policymaking, academia, and industry to develop peer-reviewed methodologies to monitor the in-situ performance of solar thermal systems.

Download the solar thermal monitoring specification

Condensing boilers and advanced room thermostats

In early 2007 the Energy Saving Trust launched field trials of condensing boilers in a sample of 60 domestic homes. to undertake detailed in-situ measurements of boiler performance, environmental conditions and household energy use over two heating seasons. The key finding from the trial was that in-situ boiler efficiency of condensing boilers was typically 5% less than published SEDBUK ratings. 

Download the condensing boiler field trial report.

Following this, the trials were extended for a further 12 months at.52 properties. These were fitted with advanced room thermostats (with Time Proportional Integral (TPI) functionality) and monitoring continued with the objective of observing any change in energy use generated by the new controls.

The results from this trial did not identify a significant improvement in the heat efficiency of the heating systems from the operation of TPI controls. Periods of effective TPI control were identified from the dataset but these occurrences were not common. A key issue is that many of the homes do not reach their set-point temperature, essential for the TPI functionality to activate.

Download the TPI extension of the condensing boiler field trial report.

Advanced room thermostats

Alongside the detailed Condensing Boiler and Advanced Heating Controls field trials the Energy Saving Trust undertook a wider trial in 600 domestic properties to establish the energy saving potential of Time Proportional Integral thermostats (TPI) in a wider sample of properties..

LED lighting in communal areas of social housing

Building on research by the Energy Saving Trust, which concluded that good quality LEDs could potentially improve lighting levels while consuming less energy, the EST developed a field trial to evaluate the performance of LED lighting installed in 33 typical social housing sites. The majority of the products were simply retrofitted in place of the old lighting installations.

 Key conclusions from the work show that:

• the new LEDs have performed in line with the trial's performance specification
• lighting levels have significantly improved since the LEDs were installed
• the new LEDs will generate significant energy savings for the social housing tenants
• the long lifetime of the LEDs will significantly reduce lighting maintenance costs for the housing managers.

Domestic hot water monitoring field trial

The energy used to heat domestic hot water represents a significant proportion of a home's heating bill. The Energy Saving Trust undertook a field trial measuring temperatures of delivered hot water in 120 homes across the UK ti update knowledge on the amount of hot water used in domestic homes and the energy used to heat it.

Before the trial it was assumed that the temperature of domestic stored hot water was considered to be 60°C. The mean temperature among dwellings fitted with regular boilers was 52.9 ± 1.5°C. In houses with combi boilers it was 49.5 ± 2.0°C. This difference is highly statistically significant, and it was concluded that combi boiler owners routinely experience lower hot water delivery temperatures than conventional boiler users. These low storage temperatures also raised the potential of Legionella risk.

Cold feed temperatures were found to be higher than expected. This, coupled with the lower temperature of stored hot water, meant that the BREDEM model assumption of a 50°C temperature rise between cold feed and stored temperature was in reality only 37°C. The energy used to heat domestic hot water was therefore lower than previously thought and this element of the BREDEM model was significantly revised following the study.

Smart Home Energy Management (SHEM)

The Energy Saving Trust defines SHEM as a holistic, whole-house approach to using technology to radically change the way that energy is supplied to and used in the home. The technology is new to the global market and can take many different forms, from simple smart meters to whole-house control regimes. The Energy Saving Trust is working with a wide spectrum of the UK industry, including technology providers, energy suppliers and policymakers, to design a field trial of SHEM technology in customers’ homes.

Potential aims of such a trial might be:

• Home energy controlling hubs that will collect real-time or near real-time data on energy consumption data from smart household appliances and enable intelligent automation.
• Facilitating long-lasting behavioural change amongst end users
• Strengthening the distribution grid by providing control systems, management and decision support tools that enable the integration of renewable energy sources, both large scale production (e.g. wind and solar farms) and massively distributed production (e.g. residential and tertiary buildings).
• Advancing security and reliability, as well as protection of equipment, fault detection and alert, and self-healing through development of the necessary high power electronics.
• Development of data management infrastructures to allow electricity production and consumption to be measured, reported and controlled (and eventually credited or billed).
• Building consensus on industry-driven open standards to ensure the interoperability of smart grids control and management systems.

MicroCHP

The Energy Saving Trust is currently working with relevant technology providers and the trade bodies to develop a comprehensive proposal to undertake a UK-wide field trial of micro combined heat and power (mCHP) technology installed in customers’ homes. We are particularly interested in the impact of mCHP technology on local electricity networks. Please contact the team to find our more about our plans.

Solid wall insulation

The Energy Saving Trust commenced field trials of solid wall insulation in 2010 to identify the barriers and challenges of installing solid wall insulation, and understand customers’ perceptions of the installation process. 75 solid walled properties throughout England are involved in the trial.

The aims of the trials are:

• to establish the in-situ performance of a wide variety of solid wall insulation systems, with a focus on reduced energy consumption and carbon savings
• to gain valuable learning and experience of the issues relating to the installation of solid wall insulation by conducting trials
• to provide independent, verifiable data in order to demonstrate the energy efficiency potential of solid wall insulation measures.

The first phase of the field trial, completed in Spring 2011, collected baseline data from the energy and fabric performance of each dwellings. A wide range of measurements were undertaken, including air tightness testing, gas / electricity use, internal / external temperatures, wall U-Value measurements, internal / external thermography, SAP assessments, wall surface temperature measurements and internal humidity.

External and internal solid wall insulation will be installed as appropriate in the 75 properties during the summer of 2011, with post-insulation monitoring undertaken to determine the energy saving potential of the measure. The trial will also involve an evaluation of the customer experience the participating householders have received. We will also report on any issues encountered with planning permission activities. A final report will be released in Summer 2012.