Six years after Derby’s social housing development saw the installation of Vaillant’s aroTHERM air source heat pumps in 54-flats, the predicted benefits are continuing to be realised.

From ongoing energy cost savings and tenant satisfaction to a collaborative partnership between Vaillant and Derby Homes, the retrofit scheme has been positively received by all stakeholders.

In 2017, social housing provider, Derby Homes embarked on a major heating system retrofit project alongside long-standing partner Vaillant at its Rivermead House site, compromised of 54 one and two-bedroom flats.

Residents had found the legacy electric storage heating system hard to control and expensive to run. So, Derby Homes, with support and guidance from Vaillant, decided to embrace the benefits afforded by low carbon heating technology to provide a more reliable and cost-efficient heating solution, that would also be easy to install and maintain.

Located off the gas grid, Vaillant’s aroTHERM 5kW air source heat pump, was the ideal solution and was installed on the balcony of each of the flats.

Six years on since the completion of the installation programme, it is safe to say that all tenants remain very happy with the results of the air source heat pumps, and the decision taken by Derby Homes.

Both Derby Homes and their residents continue to enjoy a positive low carbon technology experience. Uncomplicated installation and ongoing maintenance benefits for the company are coupled with tenant energy cost savings and a high level of resident satisfaction with the low carbon heating and hot water solution.

The Challenge

Derby Homes is an arm’s length management organisation (ALMO) created by Derby City Council to manage, maintain and improve its social housing.As a non-profit entity, it received extra government support to carry out a major programme of repairs and improvement work. Having undergone a process of assessing all the properties in its portfolio, Rivermead House was identified as requiring a more efficient heating system to reduce carbon emissions and lower fuel bills for tenants.

The organisation initially considered running a microdistrict heat pump, using energy from the ground or the local river. However, these options were ruled out as potential costs were coming in at over £13,500 per flat. A solution which could be easily installed with as little disruption for tenants as possible, at an affordable price, was needed.

Upon surveying the site, the Vaillant team immediately recognised that the balconies of each flat would be an ideal space to house an air source heat pump. However, with pressure on budgets, savings needed to be made wherever possible. To do this, Derby Homes undertook the system fitting, as opposed to using a contractor.

Vaillant supported their in-house team of installers every step of the way, offering full training on the air source heat pumps, and visiting the site at least once a week to give continued assistance and guidance to the installers.

Each flat was installed with its own aroTHERM 5kW air source heat pump, VRC 700 weather compensating system control and a 150-litre slimline hot water cylinder. Costs were successfully kept to a minimum, with each flat fitted for £6,000 - a huge 30 per cent saving against a comparable quote.

Tenants have seen a huge reduction in their fuel bills. With the previous storage heating system, the average energy consumption of 13068 kwh equated to costs of around £1,250 a year. With aroTHERM heat pumps in place, bills have been slashed to £730 per annum, providing a typical saving of £520 a year per household.

The installation also means that Derby Homes can take advantage of the domestic Renewable Heat Incentive (RHI).

It is projected that over the next seven years, over £196,000 will be claimed by Derby Homes. What’s more, the training and professional qualifications that Derby Homes installers have now obtained can be applied to other projects in the future.

David Pickering, Gas Supervisor, Derby Homes:

“Thanks to Vaillant’s help throughout the process, the feedback and support of the tenants has been excellent, there have been no problems whatsoever. The new heat pump systems are a major improvement on the electric storage heaters, and now the residents can enjoy affordable control of their heating throughout the entire flat.”