Issue 8 - Ground Source Heat Pumps

Issue Date : 23rd June 2009

Welcome back to the Newry Democrat’s Renewables and Energy saving section brought to you by Kellys Renewable Energy Solutions (www.kellys.uk.com). This week we will discuss ‘Ground Source Heat Pumps’. Due to fluctuating fuel costs, people are looking to alternative economical ways to heat their homes.

Ground Source Heat Pumps (GSHP) takes low-grade energy from the ground and converts it into usable energy at a higher temperature for space and water heating. They work on the same principle as a refrigerator but operating in reverse. The ground is usually heating to a temperature of 12°C by the sun, with the heat pump actually making use of solar energy.

The most common type of GSHP is that of a closed-loop system. In a closed system the heat exchanger in the ground consists of a sealed loop pipe which is buried in horizontal trenches or if space is restricted horizontally the pipes are installed in vertical boreholes between 50m and 90m deep.

GSHP’s require energy to run the pump. The ratio of the kW (Kilowatt-unit of electricity) of heat energy produced by the system to the kW of electrical energy needed to power the pump is known as the coefficient of performance (CoP). The majority of systems have a CoP of between 3 and 5, meaning that up to five times the amount of energy is produced than it takes to run the system. GSHP’s are normally only appropriate for new builds due to the required area needed outside and secondly they work best with an under floor heating system as it runs at a lower temperature than conventional radiators. At Kellys we supply, install and commission all ground source heat pumps, and with our GSHP you can obtain a grant of up to £1,200.