Water source heat pump in Whitchurch, Hampshire

This beautiful property in Hampshire was once where paper for the Bank of England was manufactured. The owners have spent many years transforming the grounds and gardens to stunning effect, reflecting the natural beauty of site while taking inspiration from their travels around the world.

The problem

Large, older buildings like those on this site have a high heat demand and, without extensive renovation, often a high rate of heat loss. The customer was seeking a efficient and cost-effective alternative to a fossil fuel system to install on a barn conversion on the property. With an existing water source heat pump on the property and access to a river which has powered the on site mill for centuries, the customer was well aware of the savings to be made from this technology.

The solution

A problem that can sometimes occur with open-loop water source heat pump systems, which pump water from a nearby source like a river or stream past a heat exchange before returning it to the source, is the sediment and other debris that can be drawn with the water. This can lead to problems with blocked filters which stop the system working – the existing water source heat pump on the property requires regular, fortnightly cleaning to keep it operational. The solution for this property, which has a slow flowing stream running through the site, was an energy blade, which sits in the water drawing heat energy from the water as it flows by, before converting it into higher temperatures for heating and hot water.

The benefits

The energy blade heat pump system is capable providing up to 24kW of heat with just a slight flow of water running past it (without a flow the water can potentially freeze). As it is a closed-loop system, no filtration of the water is required as no water is pumped from the source, so maintenance of the system is minimal. These practical benefits run alongside the savings and energy efficiencies that come with all WDS heat pump systems. The Government RHI payments paid against the heat energy produced provide a regular income which covers for the capital cost of the system within five to six years, while at the same time the system is around £400 a year cheaper to run than an equivalent fossil fuel system.