Upgrading water heating systems in social housing stock

Thursday, July 27, 2017
Anyone with a role in the development, maintenance or refurbishment of Social Housing properties will understand the range of potential issues that arise when work has to be undertaken.

One key area of any upgrade is the heating and hot water supply, which in itself offers various challenges, from costs and installation time, to space and sizing.

Of course, upgrading a hot water system is vital to future-proofing any property and to ensure that both tenant and landlord are receiving acceptable performance allied with maximum energy efficiency. This is to ensure that energy costs remain affordable and that tenants receive a good service.

Social Housing varies enormously across the UK, from family-sized detached homes to one-bedroom flats. Each will therefore have a very different requirement from a hot water system, whether that be heating, bathing or general use.

The refurbishment of this system often requires more than a straight-forward exchange. The scope of works can include removal of existing cylinders, storage tanks and external vessels, replacing pipes and potentially constructing new storage spaces.

Challenges can arise with the physical size of a cylinder and the space available to install a new vessel. For high-rise or multi-storey properties access can also be a problem.

This can all lead to rising costs as the installer will have to spend more time on the planning and ultimately the installation itself. It is therefore mandatory to spend time beforehand checking the exact specifications of product, property size, likely hot water usage and available space.

Manufacturers generally provide a range of models with differing volumes and in some cases a slimline model to fit tighter spaces where access may be limited, which will still deliver high flow rates to meet the modern demand for hot water.

For example the Fabdec SuperSlimline is only 450mm in diameter, so was a perfect solution for one social housing client who was retrofitting a block of flats and had restrictions with cupboard size.

Once the cylinder is installed, certainly in the case of an unvented or pressurised system, there will be a need for regular maintenance – annual checks are recommended. Also on life-cycle costs, a key point for consideration is that a sub-contractor will have to liaise directly with the tenant to gain access to their property.

Some of these tenants could be vulnerable persons and will therefore need to be treated accordingly. There could also be issues with tenants being unable or unwilling to answer their door and allow access.

Having to return to properties and complete the necessary administration is a further pitfall.

However, there are ways to minimise the impact of this.

When unvented cylinders were first approved for use in the UK in 1986, to accommodate for the expansion of the water as it is heated inside the water tank, an external pressurised expansion vessel had to be installed in the piping system.

Whilst there was also an allowance for limited internal expansion in the system, the expansion vessel was a necessary additional fitting which could cause multiple installation issues. It would need extra space and was another functioning part of the system that would require regular maintenance – including having to be re-pressurised throughout its life cycle.

As technology developed, the next innovation was an internal expansion device – commonly known as a floating baffle – which is still used extensively today.

This causes issues however, as the air gap or ‘bubble’ has to be re-charged, which may or may not be frequent dependent on the conditions of use.

Because the baffle is designed to move up and down the dip tube outlet length (as the water level fluctuates) there is wear-and-tear plus the outer ring can never fully seal against the inner wall of the vessel; so ultimately, the system still requires maintenance.

At Fabdec we researched a system that would be totally self-sustaining, replenishing the internal expansion device permanently, with no need for recharging or regular servicing.

The resulting 3S Technology is now used across our Excelsior WXI unvented water heater range, which has no internal, moving parts in the cylinder and is very much a fit-and-forget product. Maintenance is minimised to the extent that only a pressure relief valve check would be necessary, a simple and quick process.

Housing Associations can spend a lot of time planning for the regular upkeep and maintenance of water heating systems, as well as liaising with sub-contractors to carry out work and respond to call-outs when problems arise.

With the fast-improving technology and design in the water heating sector, replacing cylinders as part of improvement works is easier than ever; and in the long-term, the efficiency and financial savings will far outweigh any initial cost outlay on purchasing a product and paying for its installation.