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❄️ HEATING & COOLING IN ONE SYSTEM

Cooling from
Ground Source
Heat Pumps

As well as providing year-round heating and hot water, ground source heat pumps can work in reverse to deliver passive and active cooling — replacing the need for traditional air conditioning with a more efficient, sustainable solution.

2-in-1
Heat & Cool
Zero
Carbon*
£7,500
BUS Grant

*When paired with a renewable electricity tariff

Cooling with a ground source heat pump diagram

Two Ways to Cool Your Property

Ground source heat pumps offer both passive and active cooling

🌿

Passive Cooling

Also known as "Free Cooling"

The brine circulates through ground collectors where it is naturally cooled by the lower ground temperature, then passes through a heat exchanger to provide chilled water. The heat pump compressor is not used — only the circulation pump runs, making it extremely energy efficient.

How it's distributed:

Fan Coil Units Underfloor Cooling
✅ Advantages
  • Very low running cost — only circulates fluid
  • No compressor needed — minimal energy use
  • 100% carbon-free with renewable electricity
  • Recharges ground heat for improved winter efficiency
  • Simple integration with existing GSHP system
⚠️ Considerations
  • Less effective than active cooling — not as cold
  • Condensation risk with underfloor — dewpoint measurement recommended
Best for: Properties that don't get excessively hot
❄️

Active Cooling

Compressor-driven cooling

The heat pump's evaporator and condenser circuits are reversed, allowing the compressor to actively extract heat from the building and transfer it into the ground via the boreholes or ground collectors. This delivers much colder temperatures comparable to traditional air conditioning.

How it's distributed:

Fan Coil Units Underfloor Cooling
✅ Advantages
  • Maintains a set cooling temperature — much more effective
  • Performance comparable to traditional air conditioning
  • 100% carbon-free with renewable electricity
  • Recharges ground heat for improved winter efficiency
  • One system for both heating and cooling
⚠️ Considerations
  • Slightly higher running costs than passive (still far less than AC)
  • Can be limited by borehole capacity to disperse heat
  • If brine overheats, compressor efficiency drops
How It Works

The Ground Is Your Natural Coolant

Below around 15 metres, the ground holds a near-constant 10–12°C year-round — significantly cooler than summer air. Your heat pump uses this to cool your home and recharge the ground for more efficient winter heating.

1
🏠

Heat Absorbed

Warm energy is collected from your rooms via fan coil units or underfloor pipes

2
🔄

Heat Transferred

The warmth is carried by brine fluid to the heat pump and then onwards to the ground collectors

3
🌍

Ground Absorbs Heat

The earth naturally absorbs the warmth, cooling the fluid before it recirculates back

4
❄️

Cool Air Delivered

Chilled water returns to your property, providing comfortable, even cooling throughout

☀️ Summer Cooling = Better Winter Heating

When you cool your home in summer, you're transferring warm energy into the ground. This pre-charges the earth with heat, so when winter arrives your heating system extracts it back more efficiently — a natural seasonal energy cycle that improves year-round performance.

☀️
Summer
→ 🌍
Heat stored
❄️
Winter
🌍 →
Heat extracted
vs Traditional AC

Why Choose a Heat Pump Over Air Conditioning?

One system, year-round comfort, lower bills

💷

Lower Running Costs

The system uses significantly less energy than traditional air conditioning, helping reduce your monthly utility bills. Passive cooling uses barely any electricity at all.

🔄

One System, Not Two

Heating, cooling and hot water all from a single system. No need for separate air conditioning units — saving space, cost and complexity.

🌱

Zero Carbon Potential

Pair with a renewable electricity tariff and the entire system — heating and cooling — runs 100% carbon-free. Far more sustainable than conventional AC.

🔇

Silent & Hidden

No noisy outdoor unit like air conditioning. Ground source systems operate virtually silently with all equipment inside or underground.

🔧

Low Maintenance

Heat pumps require minimal maintenance with a lifespan of 20+ years for the unit and 100+ years for the ground loops. No annual refrigerant checks or filter changes like AC systems.

🏛️

£7,500 Government Grant

The Boiler Upgrade Scheme provides up to £7,500 towards installing a heat pump — a system that heats and cools. No equivalent funding exists for standalone air conditioning.

Do Ground Collectors Affect Cooling Performance?

Yes — the type of ground collector makes a difference. Boreholes and water source collectors are the most effective for cooling because they typically interface directly with groundwater, which allows much higher heat transfer rates.

There's also a dual benefit: when you use your ground source heat pump for cooling in summer, you're transferring warm energy into the ground. This pre-charges the ground with heat, making your heating system even more efficient when winter arrives — a natural seasonal energy cycle.

Summer
☀️ → 🌍
Heat stored in ground
Winter
🌍 → 🏠
Heat extracted back

Frequently Asked Questions

Common questions about cooling with a heat pump

Most modern ground source heat pumps can provide passive cooling, and many models also support active cooling. However, this needs to be specified at the design stage so that the correct equipment and controls are included. Not all heat pumps have active cooling capability built in, so it's important to discuss your requirements early.

If your property doesn't get excessively hot and you want the most energy-efficient option, passive cooling is ideal — it uses virtually no electricity. If your property reaches uncomfortably high temperatures in summer and you want air-conditioning-level performance, active cooling is the better choice. Both options are far more efficient than standalone air conditioning.

Yes, chilled water can be circulated through underfloor heating pipes to provide gentle, even cooling across the floor surface. However, care must be taken with condensation — if the floor surface temperature drops below the dewpoint, moisture can form. We recommend using a dewpoint measurement controller to manage the cooling water temperature and prevent this.

Fan coil units are compact devices installed in individual rooms that blow air over a coil carrying chilled water. They provide rapid, controllable cooling similar to a traditional air conditioning unit but powered by your heat pump system. You would need one in each room that requires climate control.

The £7,500 Boiler Upgrade Scheme grant is for installing a heat pump to replace a fossil fuel heating system. The grant covers the heat pump itself — which can then also provide cooling. So while the grant doesn't specifically fund "cooling", by installing a qualifying heat pump you gain both heating and cooling capability from the same subsidised system.

Passive cooling costs very little to run — only the circulation pump uses electricity. Active cooling uses more energy as the compressor is engaged, but running costs are still considerably lower than traditional air conditioning systems. Both methods are far more energy-efficient than standalone AC units.

❄️

Interested in Heating & Cooling from One System?

Get in touch for a free, no-obligation estimate or speak to our team about adding cooling capability to your ground source heat pump installation. We'll help you choose between passive and active cooling based on your property and preferences.

Up to £7,500 available through the Boiler Upgrade Scheme