The way we heat our homes is a crucial aspect to consider in the pursuit of sustainable living and reducing carbon emissions. One technology that's gaining traction in this regard is the air source heat pump. But what exactly is an air source heat pump, and how does it work?
In essence, an air source heat pump (ASHP) is a renewable heating system that extracts natural heat from the outside air to warm your home and provide hot water. Despite their name, these pumps can operate efficiently even in colder climates, making them suitable for various regions.
But if you’re thinking about investing in this amazing technology, you need a better understanding of how they work and whether they’re worth it.
So, to help you in your quest, here’s the Heat Pump Gang guide to understanding air source heat pumps!
At their core, air source heat pumps function on the well-established principle of thermodynamic heat transfer, using a special liquid refrigerant gas to move heat from one place to another. Here's a closer look at the simplified stages involved:
Unlike traditional gas boilers that generate heat through combustion, ASHPs are incredibly resourceful. They can extract heat even from surprisingly chilly outside air, thanks to the laws of thermodynamics. Even at temperatures as low as -15°C, there's residual heat present in the air, albeit at a much lower level than what we typically feel as comfortable warmth. The ASHP's outdoor unit acts like a special heat sponge, cleverly designed to absorb heat from this low-grade thermal energy from the surrounding air.
Once the heat is absorbed by the refrigerant, it's time to get it up to temperature. This is where the magic of compression comes in. The ASHP uses a compressor, similar to the one in your fridge but much more powerful, to squeeze the refrigerant. This process of pressurising the refrigerant has a fascinating side effect: it concentrates the absorbed heat energy, significantly raising its temperature.
Now that the refrigerant is warm, it's time to put that heat to good use! The high-temperature refrigerant travels indoors and passes through a cleverly designed component called an internal heat exchanger. This exchanger acts like a bridge, transferring the energy from the warmed-up refrigerant to the water circulating in your central heating system (like radiators) or even to a hot water cylinder for showers and baths.
After giving up its heat, the refrigerant is now significantly cooler. It travels back outside to the outdoor unit, ready to start the whole process over again. This continuous cycle ensures a steady flow of heat into your home as long as heating or hot water is needed.
It's important to note that throughout this cycle, the refrigerant remains in a closed-loop system. This means the same refrigerant circulates repeatedly, absorbing heat outdoors, getting compressed to raise the temperature, transferring the heat indoors, and then returning outside to start anew. The only external input the system requires is a small amount of electricity to power the compressor and other components.
it's important to understand that there are two different types of air source heat pump system to choose from, each with its own strengths and applications:
Air-to-Water Heat Pumps
Air-to-water heat pumps (AWHPs) are designed to provide both central heating and hot water for your home.
Here's an explanation of the process:
Air-to-Air Heat Pumps
Air-to-air heat pumps (AAHPs) take a more direct approach to heating your home. They function similarly to air conditioning units, but with a clever twist: they can also reverse the process to provide warmth during those chilly months.
This is how they work:
The decision between an AWHP and an AAHP depends on your specific needs and existing home setup. AWHPs are a great choice if you're looking for a complete heating and hot water solution, particularly if you already have a water-based (wet) central heating system. AAHPs offer a more targeted approach, ideal for heating specific areas or providing year-round climate control with both heating and cooling capabilities. Consulting with a qualified heating engineer can help you determine the best ASHP type for your home.
There are several compelling reasons to consider an air source heat pump for your home, although it’s always wise to weigh up all the facts before committing yourself.
Heat Pump Gang is here to guide you in your decision! We believe in openness and transparency to provide the consumer with a fair and honest assessment. With this in mind, here are the pros and cons of air source heat pumps.
We'll begin with the obvious plus points before moving on to explore any possible downsides;
Compared to traditional gas boilers and conventional heating systems, ASHPs can be much more efficient. They can potentially deliver up to three times more heat energy than the electrical energy they consume, resulting in lower annual energy bills and a reduced carbon footprint.
You get heating and cooling all in one system! There's no need for a separate heater and air conditioner; with an air source heat pump, you can enjoy comfortable temperatures in your home year-round, adjusting to your needs with ease.
We should also address a common myth about underfloor heating; heat pumps aren't just used to power underfloor heating! As we've seen above, they can provide cool air and heating independently of underfloor heating, although these systems are a wise investment as well that will save money on your heating bills.
Some consumers may be able to take advantage of financial incentives to encourage the switch to ASHPs, making them a more attractive option. For example, the Renewable Heat Incentive (RHI) provides financial support to homeowners who install renewable heating systems like air source heat pumps, helping to offset the initial investment and promoting sustainable energy use.
Air source heat pumps provide consistent heating and cooling, maintaining a comfortable indoor environment regardless of the outdoor temperature. They also offer precise temperature control, allowing you to set the perfect temperature for different rooms in your home.
Unlike some traditional heating systems that can be noisy, air source heat pumps operate quietly, ensuring a peaceful living environment.
While air source heat pumps offer numerous advantages, there are a few things to keep in mind:
Installing an ASHP can be more expensive upfront than traditional heating. However, it's essential to consider the long-term savings on energy bills and potential government incentives, which can offset the initial investment. Another example is the Boiler Upgrade Scheme (England and Wales only), where you get £7,500 towards the cost of an air source heat pump.
Check out: Air Source Heat Pump Cost
While ASHPs can extract heat from cold air, their efficiency may decrease in extremely cold weather. However, technological advancements have improved the performance of ASHPs in colder climates, making them a viable option for many regions.
ASHPs work best in well-insulated homes. Proper insulation helps retain the heat generated by the heat pump, maximising its efficiency and reducing energy consumption. Before installing an ASHP, it's advisable to assess your home's insulation and make any necessary improvements to ensure optimal performance.
Also, ASHPs don't produce the same level of heat as gas boilers, so you may need to invest in bigger radiators for space heating.
Discover: Advantages And Disadvantages Of Air Source Heat Pumps
In addition to the two choices (air-to-air or air-to-water), there's an alternative to these two air source heat pumps that it's only fair to mention; ground source heat pumps (GSHP).
We won't go into too much detail here, as you can read all about this subject in the Heat Pump Gang blog, What Is a Ground Source Heat Pump?
However, here's a brief summary of the differences:
Instead of relying on outside air, ground source heat pumps draw heat from the constant ground temperature below the surface. This ground temperature remains fairly stable year-round, making GSHPs highly efficient, even in very cold weather. Installing a GSHP requires digging trenches or boreholes for pipes, which can be more expensive upfront compared to ASHPs.
It's difficult to say, as each has its benefits, and both are far more efficient heating methods than gas boilers or electric storage heaters.
While the GSHP is perhaps better for colder weather, air source heat pumps work more efficiently all year round, as the air temperature is generally warmer than the ground. A ground source heat pump is also better suited to larger properties.
Both rely on ambient heat, but one draws it from the air and the other from the ground.
Ultimately, it depends on your budget and how much you are prepared to invest. While both air and ground source heat pumps offer impressive energy efficiency, the question remains: will the long-term savings outweigh the initial cost of installation? The answer depends on your location and its impact on ground and air temperatures.
If you're unsure about the answer, the friendly team at Heat Pump Gang would be delighted to offer their expertise!
While air source heat pumps are a fantastic energy-efficient option for heating your home, they might not always be the perfect solution in very cold climates (as mentioned above).
Hybrid heat pumps overcome this issue by combining the eco-friendly nature of an ASHP with the reliable warmth of a traditional gas boiler, offering the best of both worlds.
Here's a basic idea of how they do this:
During most of the year, the ASHP handles things. As explained earlier, it efficiently extracts heat from the outside air, even on cooler days, and transfers it to your home's heating system. This makes the most of renewable energy and keeps your running costs down.
When the outdoor temperatures plummet, and the ASHP struggles to maintain comfortable warmth, the gas boiler seamlessly kicks in to provide additional heating. This ensures your home stays cosy and warm, even on the frostiest days.
Hybrid systems are equipped with smart controls that constantly monitor the outside temperature and your home's heating demands. This allows the system to automatically switch between the ASHP and the boiler, ensuring efficient and cost-effective operation.
To be fair, they require a larger investment, as you need to install both a heat pump and a boiler. Average costs for hybrid systems generally come somewhere between £10,000 and £19,000, depending on the size and scale.
This area can be a source of concern for consumers, understandably! Nobody wants too much disruption around the home, and it's only natural to know how long this job will take and whether it will cause a mess.
Let's run through the Heat Pump Gang air source heat pump installation process and put any fears to rest:
Air source heat pumps have emerged as a strong contender, but are they the answer to our future heating needs? Let's explore the reasons why they might just be...
By weighing the benefits and considerations, you can make an informed decision about whether an air source heat pump is the right choice for your home. Consulting with a qualified Heat Pump Gang air source heat pump installer can also provide valuable insights and help you determine the most suitable heating solution for your needs.
Even so, we'll summarise what we've learned here with the top-five FAQs to help you figure out the answer...
1. Can an air source heat pump keep my home warm enough in winter?
ASHPs can efficiently heat most homes in the UK climate. They function well down to temperatures around -15°C. However, in extremely cold spells, their efficiency might dip slightly (which is why some people prefer the ground source heat pump, as it copes better in cold conditions). Some ASHPs can be paired with a conventional boiler system to provide backup heating for these rare occasions.
2. Are air source heat pumps expensive to run?
No, ASHPs can be very cost-effective in the long run. They boast high efficiency, meaning they use less electricity to generate heat, even when compared to an a-rated gas boiler. This translates to potential savings on your energy bills. Additionally, government grants can help offset some of the upfront installation costs.
3. Can an air source heat pump also cool my home in summer?
Many ASHPs function as reversible air conditioners. They can extract heat from your home during hot weather, providing a cool and comfortable environment. This eliminates the need for separate air conditioning units, potentially saving you money on additional systems and electricity bills.
4. Is my home suitable for an air source heat pump?
A well-insulated home is ideal for an ASHP to function at its most efficient. A qualified heating engineer can assess your home's insulation levels and advise on the suitability of an ASHP system.
5. How much does it cost to install an air source heat pump?
The installation cost can vary depending on the size and brand of the system, as well as any modifications needed for your home. As a rough guide, expect to pay between £8,000 and £14,000.
However, the government makes this a more financially attractive option for homeowners seeking a sustainable heating solution.
Now you know how a heat pump works, along with all the positives and negatives. Now it's time to make that decision to future-proof your home with an air source heat pump from Heat Pump Gang!
