Earth Notes: White Paper: OpenTRV North London Homes Trial (2015 to 2017)

Updated 2024-02-19.
Cost, comfort, control. Brief on OpenTRV's 58-home winter field trial of its TRV1.X smart thermostatic radiator valve in Wembley/Brent social housing.

Executive Summary

Radbot is an evolution for your heating systems.

Radbot saves tenants 30% to 50% of their heating bills and carbon footprint, while helping to manage property assets better.

Target Audience of this Paper

Local authority and other housing providers. Finance, sustainability and regeneration executives.

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Report PDF (20171208-1)

What is Radbot

Radbot brings tried and tested commercial building heating efficiency techniques to the home, by only heating rooms that are actually in use, driven by unobtrusive occupancy sensing and soft zoning, ie radiator-by-radiator control without new pipework. Radbot can be fitted without requiring skilled trades or building works. From a user perspective, it requires no complex interactions with apps or programmable displays, unlike other smart heating solutions. It's fit and forget, working intelligently in the background delivering real savings. Radbots can be fitted in place of individual traditional mechanical TRVs for a target 30% energy saving per upgraded radiator. Radbots can also be fitted alongside a companion boiler controller in place of a conventional whole-house two-wire mechanical thermostat to raise target savings to 50%.

Radbot superhero

How Does Radbot Work?

Radbot brings tried and tested commercial building heating efficiency techniques to the home, by only heating rooms that are actually in use, driven by unobtrusive occupancy sensing and soft zoning, ie radiator-by-radiator control without new pipework. Radbot can be fitted without requiring skilled trades or building works, or tricky programming or connecting to the Internet. Nor are there any complex interactions with the occupiers - fit and forget. Radbots can be fitted in place of individual traditional mechanical TRVs for a target 30% energy saving per upgraded radiator. Radbots can also be fitted alongside a companion boiler controller in place of a conventional whole-house two-wire mechanical thermostat to raise target savings to 50%. Those energy savings are money in the bill-payer's pocket, and also cut carbon emissions and climate change.

Case Study: Brent

Overview

Aim:
Test innovative energy saving products that have the potential to support fuel poor households
Lead Organisation:
Energy Solutions
Partners:
OpenTRV, Network Homes, National Energy Action [NEA] - Funder
Location:
58 social housing properties, Brent, North West London
Duration:
16 months – Dec 2015 – Mar 2017
Cost:
£35,000

The challenge

NEA launched its Technical Innovation Fund in 2015 with the aim of evaluating new innovative technologies that had potential to support UK households in fuel poverty. In partnership with local fuel poverty charity Energy Solutions and social housing provider Network Homes, OpenTRV secured funding to deliver a 16-month field trial of Radbot. The project presented an opportunity to test Radbot in a real-world scenario with the aim of verifying energy saving calculations and developing valuable insights into product user acceptability, installation and maintenance and data collection and analysis procedures.

From a pool of ~400 homes with EPC [EPC] ratings below C and identified as at risk by Network Housing, Energy Solutions conducted a user-engagement exercise recruiting 58 homes to participate in the trial. About 200 prototype Radbot units were installed during the winters of 2015--2017 along with gas consumption monitoring equipment to enable accurate energy use to be calculated. During the installation, each household also received face-to-face advice on how the product operated as well as general energy saving tips.

The results

The trial produced a number of useful insights.

  1. Verification of 30% energy saving — for households where a full data set was obtained (4), an average 30% reduction in gas consumption was observed. Drop outs and technical issues with remote data gathering unfortunately resulted in a smaller than forecast data set. This in part was due to the vulnerable and transient nature of the trial population group.
  2. Product acceptability — the majority of feedback on product usability and understanding was positive with people reporting that its similarity to a standard TRV made it easy to understand. Some households raised concerns over the noise of the motorised screw value particularly when located in bedrooms and the robustness of the mechanical connection of the device to the radiator valve. OpenTRV is using this feedback on the prototype to improve the design and performance of its next generation Radbot.
  3. Data sharing — participants were more receptive than anticipated to the sharing of data. 98% of households agreed to provide consent for their energy consumption and Radbot data to be collected and shared with selected third parties indicating that where a tangible benefit is perceived to exist for a household, the sharing and use of data sharing is acceptable.

Radbot Benefits in More Detail

Benefits for tenants

  1. Reduced energy bills — from the moment they are fitted, Radbots will start to optimise control of the heating system only providing warmth when it's actually needed. This has the potential to reduce consumption by 30%+ delivering saving of £200 - £300 pa for an average household using gas fired central heating. Carbon savings are expected to be ~0.2tCO2 to 0.25tCO2 per radiator per year.
  2. Improving comfort — tenants no longer have to suffer rooms that are either too hot or too cold. Radbot learns the individual occupancy and heating requirements for each room ensuring just the right temperature wherever you are in the house.
  3. Maximum benefit for minimum effort — nobody wants to spend time fiddling with complex controls or regularly logging into an app to control their temperature. Radbot takes care of the hard work, working intelligently in the background to save money and improve comfort.

Benefits for housing providers

  1. OpenTRV aims to empower housing providers to deliver affordable warmth for their tenants — reducing tenants' risk of fuel poverty and improving their finances which in turn can help to reduce the incidence of rental arrears.
  2. Sustainable communities — wide-scale rollout of Radbots has the potential to make a significant reduction in carbon emissions. We estimate that if a Radbot was fitted to every radiator in the UK this would reduce the UK's carbon footprint by 5%.
  3. Encouraging positive change — Radbot data can be analysed at an aggregate or individual level to provide direct feedback to tenants and encourage positive behaviour change eg drying clothes on radiators where high humidity is detected.
  4. Efficient asset management — remote occupancy monitoring for detection of illegal subletting or void management insurance criteria; early warning of damp and mould growth or trend analysis of boiler faults to improve maintenance interventions. When combined with other data sets these are just some of the ways in which Radbot data could be used to provide cost efficiencies.

These are just some of the ways Radbots could support housing associations deliver sustainable inclusive communities.

Technical Overview
Product Function Energy Savings [i] Cost Payback [ii] Installation Maintenance
Radbot Smart Thermostatic Radiator Valve (TRV) using real time occupancy and temperature sensing to provide room by room zonal heating control Up to 30% standalone ie ~0.2tCO2/y rising to 50% with boiler controller ~£30 ~1 year Simple screw-on replacement for existing TRVs – no skilled trade required Periodic battery replacement 1-2 years
Boiler controller Boiler control unit works in conjunction with Radbot devices to reduce boiler run-time Helps Radbot achieve 50% ~£60 ~1 year 2 wire connection to boiler thermostat circuit – qualified electrician None
Data service Secure AES-GCM real-time radio comms in various forms, typically including temperature, relative humidity, occupancy and device status Up to 60% on heat, savings on asset management Various service levels Typically one small data relay unit covering one or more dwellings None
  1. Energy Savings are calculated using typical scenarios and trial data.
  2. Target payback period based on forecast energy saving and purchase costs.

Conclusion

Radbot is a painless incremental low-risk route to improve tenants' heating and even health, especially where building fabric updates are difficult. Those savings are also in money and CO2 emissions.