Air Source Heat
Pump FAQ Hub
Frequently Asked Questions
Your questions, answered by the experts at Adlår.
Whether you’re new to heat pumps or already an Adlår customer, this FAQ hub is your go-to guide for everything you need to know. From how heat pumps work to how much they cost, we’ve answered your most common questions – and included links to in-depth blogs for those who want to dig deeper.
Heat Pump Basics
An air source heat pump extracts heat from the outside air and transfers it into your home to heat your radiators and hot water. → What Is an Air Source Heat Pump?
Modern heat pumps work efficiently in cold UK temperatures, even down to -15°C.
→ Can an Air Source Heat Pump Work in Cold UK Winters?
It replaces your boiler by providing heating and hot water using renewable energy.
→ Understanding the Efficiency of Heat Pumps: COP and SCOP Explained
Yes, many heat pumps can be reversed to provide cooling during warm weather.
→ Can a Heat Pump Provide Cooling in Summer?
Not constantly. They run in cycles and are designed to maintain steady temperatures efficiently.
→ Common Misconceptions About Air Source Heat Pumps
Yes. When installed properly and maintained, they are extremely reliable for UK homes.
→ Common Misconceptions About Air Source Heat Pumps
Like any heating system, an air source heat pump performs best when it is properly maintained, periodically reviewed, and kept operating within its intended design conditions. Over time, even small changes in controls behaviour, circulation, airflow, or system balance can gradually affect comfort, efficiency, running costs, and overall performance.
A standard air source heat pump uses air source heat from outside to heat water through a refrigeration cycle.
The Adlår FJORD cylinder includes a self-contained heat pump built into the unit. Its self-contained system draws external air in via a small ducting route to maintain consistent hot water temperatures without ever diverting energy from our space heating. → Hot water and heat pumps.
The noise of the Aurora II is between 22 and 50 decibels. Of course, this does depend on various factors such as how loud it is running, how far it is from the property boundary, living spaces, and how it is set. Our goal is to install a whisper-quiet heat pump so that, using our patented technology, the decibel level is only 22 decibels at 5 metres away.
Typically, a well-maintained air source heat pump in the UK will last between 15 and 20 years. However, several factors can increase the lifespan of an air source heat pump to 25 years or more, such as the quality of the system, optimal installation methods, and maintenance practices.
Costs & Savings
Installation typically ranges from £7,000–£14,000, but government grants can significantly reduce costs.
→ Heat Pump Costs vs. Gas Boiler Costs: A Long-Term View
Homeowners can save up to £1,000 per year depending on home efficiency.
→ How Much Can I Save on Energy Bills with an Air Source Heat Pump?
No – they are much cheaper to run than traditional heating when installed correctly.
→ Are Air Source Heat Pumps Cheap to Run?
The average UK heat pump uses 3,000–5,000 kWh annually.
→ How Much Electricity Does a Heat Pump Use?
Most homeowners recover their investment within 5–7 years.
→ What Is the Payback Period for a Heat Pump?
Yes – the Boiler Upgrade Scheme offers £7,500 off installation.
→ How Does the Boiler Upgrade Scheme Make Heat Pumps Affordable?
→ How to Apply for the Boiler Upgrade Scheme (BUS)
→ How UK Homeowners Can Access Government Grants for Energy Efficiency
From 21 July 2026, eligible oil and LPG-heated properties can receive a £9,000 Boiler Upgrade Scheme grant towards an air source or ground source heat pump installation.
While gas boilers are cheaper upfront, heat pumps save more money over time, so for homeowners looking for long-term value, heat pump installation is the smarter choice.
→ Heat Pump costs vs Gas Boiler costs: A detailed comparison.
Installation Requirements
Yes.
Heat pumps can work exceptionally well in old houses.
The key factor isn’t the age of the property. It’s whether the heating system has been designed around the building’s specific requirements. → The Truth About Period Properties & Heat Pumps
Yes.
Many cottages are suitable for heat pumps.
In fact, many cottage owners are surprised to discover that their property is more suitable than they initially expected.
The challenge is rarely the cottage itself.
The challenge is understanding how the property behaves and designing the heating system around those characteristics.
Sometimes. It depends on your home’s current efficiency and system size.
→ Do I Need to Upgrade My Radiators or Insulation for a Heat Pump?
Our dual air source heat pump installation is quick (1–2 days) and managed entirely by Adlår's in-house team.
→ Air Source Heat Pump Installation: What to Expect
Most systems require 1–2m² of outdoor space and a cylinder indoors.
→ Air Source Heat Pump Installation: What to Expect
Some compact systems can be wall-mounted. It depends on the model and property layout.
→ Air Source Heat Pump Installation: What to Expect
For sizing suggestions, follow these steps:
- Calculate Your Home’s Square Footage.
- Estimate the Required kW Output.
- Adjust for Relevant Factors.
During Adlår’s free consultation and site survey, our qualified technicians will guide you through the entire ASHP installation process, including how to choose the best size and model for your needs.
The heat loss report shows a design flow temperature. This figure often raises questions because heat pumps perform best at lower flow temperatures (ideally 35–40°C). Here’s why the report might show a higher number and how realistic it is to run at lower temperatures in practice.
Why the Report Shows a Higher Temperature
The flow temperature figure is based on MCS modelling standards, which are deliberately conservative. These calculations include safety margins to ensure the system will still deliver reliable comfort even in worst-case scenarios (very cold weather, higher heat loss than expected, etc.).
In reality, most homes perform better than these conservative figures. There is typically a built-in error margin of around 30% in heat loss calculations.
The system is also built to cover the full heating load under negative temperatures outside in worst case scenarios, usually around -2~-3°C. In reality, the UK only experiences the MCS outside design temperatures for an average of 100 hrs a year. In contrast the average UK mean winter temperature is closer to +7°C.
Combining all the safety margins put into the MCS calculation, in reality, the real-world flow temperatures are often significantly lower than the design value shown in the report.
The Advantage of the Adlår Dual Heat Pump System
One of the biggest benefits of the Adlår system is that we separate the heating and hot water demands.
- In a conventional single heat pump system, the same unit has to produce both space heating and hot water. This increases the load on the heat pump and often forces it to work at higher temperatures.
- With the Adlår dual system, the Aurora II is dedicated purely to space heating, while the Fjord handles hot water independently.
By removing the hot water load from the heating heat pump, the Aurora II can operate at lower flow temperatures for much of the time. This improves efficiency and reduces running costs.
How Realistic Is 35–40°C in Practice?
It is realistic for most homes to operate regularly at 40°C, and often closer to 35°C, during normal day-to-day use — provided the home has reasonable insulation and correctly sized emitters.
You can further improve your ability to run at lower temperatures by:
- Upgrading radiators (or adding fan-assisted radiators)
- Improving insulation
- Ensuring good hydraulic balancing of the system
Summary
| Factor | Heat Loss Report (Conservative) | Real-World Performance with Adlår Dual System |
|---|---|---|
| Design flow temperature | 50°C | Often 35–40°C |
| Hot water demand | Combined with heating | Separated (lower load on heating heat pump) |
| Safety margin | Included | Real-world results are usually better |
| Potential for lower temperatures | Not always shown | Very achievable in most homes |
Bottom line: The flow temperature figure in the report is a cautious design value. With the Adlår dual system, it is realistic and common to run at significantly lower flow temperatures in everyday use.
Efficiency & Optimisation
They deliver 3–4x the energy they consume – up to 400% efficiency.
→ Understanding the Efficiency of Heat Pumps: COP and SCOP Explained
Yes – combining solar and a heat pump further reduces running costs and carbon output.
→ How Air Source Heat Pumps Work with Solar Panels
Smart controls optimise heating patterns, reduce waste, and allow remote control.
→ The Role of Smart Controls in Maximising Heat Pump Efficiency
→ How to Make the Most of Smart Heating Controls
Two essential metrics to consider are the Coefficient of Performance (COP) and the Seasonal Coefficient of Performance (SCOP).
COP measures how efficiently a heat pump operates under specific conditions.
SCOP takes COP a step further by measuring a heat pump’s efficiency over an entire heating season rather than at one fixed point.
Heat pump commissioning is the process of configuring, balancing, and optimising the heating system after installation.
This stage ensures the system operates correctly in real-world conditions rather than simply functioning mechanically.
→ Why Heat Pump Commissioning Matters More Than Most Homeowners Realise
Most homeowners assume that once a heat pump is installed, its performance is fixed. In reality, that’s rarely the case. The biggest improvements in energy efficiency, comfort, and running costs often come after installation through correct optimisation and the right upgrades.
Smart heating controls, weather compensation, and heating curves determine how your home actually feels day to day. They influence how the system responds to changing weather, maintains stable comfort, and protects long-term seasonal efficiency.
→ Smart Heating Controls, Heating Curves and Weather Compensation Guide
When installed alongside basic insulation, a heat pump can easily shift a property from E or D to C or even B.
→ How to Maximise Your Home’s Energy Performance Certificate (EPC) Rating
The efficiency of the Aurora II heat pump improves significantly when it operates at lower flow temperatures. This is why we always aim to design systems that can run at the lowest comfortable temperature possible.
Below are the MCS SCOP values for the Aurora II range at different flow temperatures:
Aurora II SCOP by Flow Temperature
| Flow Temperature | Aurora II 6kW | Aurora II 10kW | Aurora II 14kW |
|---|---|---|---|
| 50°C | 3.48 | 3.47 | 3.46 |
| 45°C | 3.82 | 3.79 | 3.77 |
| 40°C | 4.15 | 4.09 | 4.10 |
| 35°C | 4.49 | 4.40 | 4.42 |
Key Takeaways
- Lower flow temperature = Higher SCOP (better efficiency)
- Running at 35°C or 40°C instead of 50°C can improve efficiency by 25–30%
- The 6kW model performs particularly well at lower temperatures
What This Means in Practice
| Flow Temperature | Efficiency | Running Cost Impact | Typical Use Case |
|---|---|---|---|
| 50°C | Good | Higher | Older radiators, high heat loss |
| 45°C | Very Good | Lower | Mixed systems |
| 40°C | Excellent | Significantly lower | Modern radiators or good UFH |
| 35°C | Best | Lowest | Well-insulated homes with UFH |
Recommendation
Wherever possible, we design systems to run at 40°C or below during normal operation. This is achievable in most homes with correctly sized emitters and good insulation.
Upgrading radiators or improving insulation will allow your system to run at these lower, more efficient temperatures for longer periods — delivering both better comfort and lower running costs.
Sustainability
They are a key part of decarbonising UK homes and future-proofing heating systems.
→ What Are the Environmental Benefits of Heat Pumps?
→ How Sustainable Is Your Home? A Self-Assessment Guide
→ Future-Proofing Your Home with Renewable Heating
Much lower than gas boilers – up to 70% less CO₂ emissions.
→ How Air Source Heat Pumps Help Reduce CO₂ Emissions
→ What’s the Carbon Footprint of an Air Source Heat Pump?
It’s significantly lower than fossil-fuel systems, especially when using newer refrigerants.
→ What Is the Global Warming Potential (GWP) of Your Heating System?
The UK is phasing out gas boilers by 2035, with heat pumps as a main replacement.
→ How the UK Plans to Phase Out Gas Boilers by 2035
→ What Is the Future of Home Heating in the UK?
→ The Role of Heat Pumps in the UK’s Energy Transition
→ How UK Government Net Zero Targets Impact Home Heating
They contribute to SDG 7: Affordable and Clean Energy.
→ The Role of Heat Pumps in Achieving SDG 7
Insulation, smart heating, heat pumps, and energy-efficient appliances are great places to start.
→ Top 5 Low-Cost Ways to Make Your Home More Sustainable
→ What Are the Best Ways to Reduce Your Home’s Carbon Footprint?
→ Understanding Your Home’s Carbon Footprint
Insulation, smart heating, and efficient systems like heat pumps make a huge difference.
→ How to Retrofit Your Home for Energy Efficiency
→ The Importance of Home Insulation for Energy Efficiency
Need Personalised Advice?
Every home is different. If you’re still unsure, book a free consultation or site survey to get expert guidance tailored to your property.
- 01252 268 669
- info@adlar.co.uk
- Monday–Friday, 9:00am–6:00pm
- Adlår Castra UK, Farnham, Surrey
