Ground Source Heat Pump Design

A Ground source heat pump (GSHP) system can reliably supply significantly more energy than it uses allowing a reduction in the running costs of many homes. To ensure that a ground source heat pump is operating efficiently it is important that the heat pump is correctly designed.

Heat from the ground is absorbed at low temperatures into a fluid inside a loop of pipe (a ground loop) buried underground. The fluid then passes through a compressor that raises it to a higher temperature, which can then heat water for the heating and hot water circuits of the house. The cooled ground-loop fluid passes back into the ground where it absorbs further energy from the ground in a continuous process as long as heating is required. Our design process for a ground source heat pump system adhere to the following steps:

Heat loss:

One of our initial steps is to carry out a room by room heat loss calculation of the property in accordance with MCS standard MIS3005. This process guarantees that the heat pump and associated equipment is appropriately sized to match the demands of the property and also ensures compliance with MCS standards.

Equipment selection:

Based on the heat demand and location of the property we are then able to suitably size the equipment. The equipment selected would typically include the heat pump, domestic hot water cylinder and any auxiliary equipment required and would meet the space heating and hot water demands of the property.

Depending on the land available we design a suitable ground loop system to extract energy from the ground. We design and installed both vertical groundloops and horizontal boreholes.

In horizontal ground loop systems piping is installed horizontally in trenches. The depth of the trenches will vary according to the design and soil characteristics, but is generally 1.5 – 2m deep. Horizontal loops require much more surface area than vertical loops.

The advantage of a vertical loop systems or ‘boreholes’, which consists of pipe inserted into vertical bore holes, is less space is required. Holes are spaced at around 5m intervals and can vary between 15m and 60m according to the design and soil characteristics.

Estimated running costs and benifits

We appreciate the importance of an accurate estimation of the financial savings of installing a heat pump. As well as the payments which you will receive through the RHI (Renewable heat incentive) we also aim to show you the savings that can be made against oil and LPG. We have found that well designed and installed heat pump system will save you up to 60%. Even after the RHI tariff payments cease after seven years you will continue to benefit from the lower running costs.