An overview from Latent Heat Edinburgh
If you’re considering switching to a greener, more energy-efficient heating system, air source heat pumps (ASHPs) are a leading solution for homeowners across Edinburgh and the Lothians. But how exactly do air source heat pumps work, and why are they so efficient—especially in Scotland’s climate?
At Latent Heat Edinburgh, we specialise in designing and installing high-performance heat pump systems tailored to your home. In this guide, we break down the science behind how air source heat pumps operate, step-by-step.
What Is an Air Source Heat Pump?
An air source heat pump is a low-carbon heating system that extracts heat from the air outside and uses it to heat your home and provide hot water. It works much like a refrigerator in reverse—pulling heat in rather than pushing it out.
Despite common assumptions, heat pumps don’t require high outside temperatures. They can extract usable heat from the air even when it’s as cold as -15°C, making them perfectly suited to the Edinburgh climate.
Step-by-Step: How Air Source Heat Pumps Work
Understanding the heat pump cycle can help you appreciate just how efficient and sustainable this system is. Here’s a breakdown of how air source heat pumps generate heat:
1. Air Intake
A fan draws in outdoor air and passes it over a coil filled with refrigerant. Even cold air contains thermal energy, which is absorbed by the refrigerant fluid.
2. Evaporation
The refrigerant has a very low boiling point. When it absorbs heat from the air, it evaporates into a gas.
3. Compression
A compressor increases the pressure of the gas, which causes its temperature to rise significantly—this is where most of the heat is generated.
4. Heat Exchange
The now-hot gas passes through a heat exchanger and transfers its energy to your home’s heating system (radiators, underfloor heating, or hot water cylinder).
5. Condensation
As the refrigerant cools, it condenses back into a liquid and is ready to repeat the cycle.
This process is powered by electricity, but because it moves heat rather than generates it, an air source heat pump can produce 3 to 4 times more energy than it consumes.
Types of Air Source Heat Pumps
There are two main types of air source heat pumps, each suited to different property types:
✅ Air-to-Water Heat Pumps
These are the most common in UK homes. They transfer heat to your wet central heating system and hot water cylinder. Compatible with radiators and underfloor heating.
✅ Air-to-Air Heat Pumps
These systems blow warm air directly into rooms and don’t heat water. They’re ideal for open-plan homes or commercial spaces.
Latent Heat Edinburgh specialises in air-to-water systems, which are ideal for most properties in and around the capital.
Why Is This Technology So Efficient?
Air source heat pumps are classified as renewable heating systems because:
- They extract natural heat from the air, reducing reliance on fossil fuels.
- They can reach efficiencies of over 300%, compared to gas boilers which typically operate at 90-95%.
- When powered by renewable electricity (or paired with solar panels), they can operate entirely carbon-free.
Performance in Cold Climates: Do Heat Pumps Work in Scotland?
Yes—they do! Modern air source heat pumps are engineered for year-round performance. Even during chilly Edinburgh winters, there’s still enough ambient energy in the air to keep your home warm.
Systems can be designed to perform effectively down to -15°C or lower, which covers even the coldest days in the Scottish climate although most often they are designed to a few degrees below zero.
Real-Life Efficiency: What You Can Expect
- Coefficient of Performance (COP): This measures how much heat is produced for each unit of electricity used.
- If you imagine a traditional electric bar fire with a 1kW element for a moment, switching that on for one hour uses 1 kW hour of electricity (kWh) and gives you 1 kW hour of heat energy. The COP is 1. 1 kWh in and 1 kWh out.
The COP will vary considerably from hour to hour, day to day and month to month and to give a clearer view, manufacturers state a SCOP (SeasonalCoefficient of Performance) Most systems have a COP of 3.0 to 4.0, meaning 1kW of electricity yields 3–4kWh of heat.
Our team at Latent Heat can carry out a detailed home survey to calculate your potential savings and performance.
Advantages of Air Source Heat Pumps
- Lower Heating Bills (if switching from oil, LPG, or electric)
- Reduced Carbon Footprint
- Minimal Maintenance Requirements
- Eligible for Government Grants like the Home Energy Scotland Loan and Grant Scheme
- Future-Proof – No reliance on gas or oil
Expert Installation with Latent Heat Edinburgh
We’ve installed air source heat pumps in a wide range of properties across Edinburgh, East Lothian, and Midlothian. Our expert engineers take care of everything, including:
- Site assessments
- System design
- Grant application – where to secure your funding
- Professional installation
- Long-term servicing and support
With MCS accreditation, we ensure you’re eligible for all available government funding and that your installation meets the highest industry standards.
Get a Free Quote or Home Survey
Thinking of making the switch to a more sustainable heating solution? We offer free consultations across Edinburgh and surrounding areas.
📞 Call us: 0131 445 1457
📩 Email: [email protected]
🌐 Website: www.latentheat.co.uk
Let’s help you heat your home smarter—with clean, renewable energy.