How heat pumps are helping commercial greenhouses to extend growing and lower costs

Rising fuel prices and the effects of climate change have made energy efficiency more critical than ever – including in horticulture.

In the race for greater sustainability, air ground and water source heat pumps are proving themselves an increasingly popular way to decrease costs and emissions.

So, as specialists in constructing and equipping commercial greenhouses – including installing renewable energy options – we thought we’d take a look at why heat pumps are proving so effective for commercial growers:

What is a heat pump?

Though long-established technology, heat pumps can sometimes be misunderstood.

A heat pump extracts heat from the surrounding environment and then transfers it to where it is needed. For glasshouses, this is typically in the form of hot water piped to heat emitters such as heating pipes or fan coils.

There are three principal types of heat pump.

Ground source heat pumps extract heat from the ground via a coil of pipe buried in the soil, either in an array or a borehole. The liquid within the pipework absorbs the heat before it is compressed to raise and concentrate the temperature.

Air source heat pumps use the same principle extracting heat energy from the air as it passes over it.

Water source heat pumps can extract heat from rivers, large bodies of water or even sewage treatment plants.

Though air, ground and water sources may seem cold – particularly in the winter – they actually contain significant heat energy which a heat pump can collect and compress to produce a usable heat.

The warmth which heat pumps gather from the environment is free and sustainable. However, the heat pump itself requires electrical energy to power it’s actions. The process is therefore not entirely renewable (unless powered by renewable electricity from sources such as solar or wind).

However, it is much more energy efficient than burning fossil fuels like gas and directly produces zero carbon emissions.

The amount of heat produced by a heat pump for every unit of electricity it consumes is known as the Coefficient of Performance (CoP). For example, if a heat pump has a CoP of 3.0 it will give out three units of heat energy for every unit of electricity energy used.

What is a greenhouse heat pump?

The technology which we install into greenhouses uses the same principles as domestic heat pumps but at a much larger scale.

Greenhouse are typically large spaces with poor thermal insulation properties and thus require significant heat.

Most heat pump systems often operate at relatively low temperatures, requiring more heat emitters to achieve the desired temperatures. Typically, in a glasshouse this would require more pipework, or additional fan coil heat emitters to supplement the existing pipework.

We also install ultra-modern heat pumps which can operate efficiently as higher flow temperatures, which are particularly well suited for very large glasshouse projects

This means that the heat pump can be easily integrated into an existing heating system designed for higher temperatures.

What are the advantages?

Heat pumps have three significant advantages.

The first is the major increase in energy efficiency.

By extracting heat from the atmosphere – rather than using gas, oil or electricity – they generate abundant heat with much less input. They also produce zero direct emissions, helping greenhouse operations become much more sustainable and work towards carbon neutrality.

The second major benefit for commercial horticulture is the reduction in energy costs.

Results vary depending on the specific situation but overall heating costs are typically less than conventional heating. When partnered with other renewable technologies for the electricity supply, the savings can be huge.

Growers also benefit from the ability to more accurately plan energy spend and usage throughout the year.

How can Bridge Greenhouses help?

Established in 1985, Bridge Greenhouses has been at the forefront of UK glasshouses for almost four decades, establishing commercial greenhouses throughout Britain for edible crops, medicinal plants, plant nurseries and flowers.

As well as erecting greenhouses, we supply and install screens, lighting and other control technology which helps operators maintain ideal growing conditions.

With specialist experience in the renewable heating sector, we’re increasingly installing carefully configured heat pump systems which take advantage of existing heating infrastructure and deliver industry-leading Coefficients of Performance (CoP).

If you’d like to reduce costs and increase efficiency with a heat pump in your commercial greenhouse, we’d be delighted to help.

More information on can be found at https://www.bridgegreenhouses.co.uk/renewable