The decision on whether to adopt an air source heat pump or gas boiler is increasingly becoming a critical issue among the UK residents. There are gas boilers in more than 20 million UK homes and the heating in your home contributes to about 14 percent of the carbon emissions in the UK, so your heating system can make a big impact on the environment.
Efficiency
Although the current condensing gas boilers should have a minimum efficiency of 90 percent, the air source heat pumps do have amazing efficiency levels of 300 percent to 400 percent.
Nevertheless, the initial cost difference is high as a heat pump is usually four to five times more expensive than a gas boiler but the government is offering a 7,500 pounds grant on installation.
Long-Term Performance: It is worth mentioning that a properly installed heat pump will continue to serve the purpose to perfection after 20 years, which is why this decision is made concerning both short and long-term requirements. Regular maintenance is key to ensuring optimal performance over time.
How Air Source Heat Pumps and Gas Boilers Work
It is highly important to know the basic principles of both heating systems so that you can make an informed choice on the heating solution to your home.
Gas Boiler Operation
Gas boilers have a very simple process that starts with combustion. The natural gas is introduced into the boiler where it is mixed with air to burn in the combustion chamber.
It produces a high temperature flame which transfers the heat to a metal heat exchanger. This heat is then exchanged to water that flows within the boiler.
Gas Boilers also have a Well Timed Sequence of Ignition
The ignition is sent one or two seconds before the gas line opens to prevent the build up of harmful gas. When heated the water goes through radiators or under floor pipes warming up your home due to the convection process as the hot radiators heat up the air in the area.
New condensing gas boilers have an efficiency rating of up to 94, which has a lot more in common with old fashioned models.
However, a certain amount of heat is bound to be lost through the flue system when waste gases are released.
Air Source Heat Pump Works Operation
Through the air source heat pumps, the existing heat is extracted and transferred to your house unlike gas boilers which produce heat and are operated in reverse making the air source heat pumps analogous to refrigerators. This procedure consists of four major steps:
1. Evaporation: The refrigerant takes in the heat of the external air and hence evaporates into a gas.
2. Compression: A compressor is an electrically powered compressor that raises the temperature of the gas due to an increase in its pressure.
3. Condensation: The warm air is sent through a heat exchanger through which it supplies the water in your home.
4. Expansion: Due to the expansion, the refrigerant cools down and prepares itself to take in more heat.
Note: Moreover, heat pumps do not make heat but pump it, which makes it incredibly efficient with a rating of 300-400%. Learn exactly how an air source heat pump works.
Installation and Costs
The initial cost on either of the heating systems is largely different. Time and money are very significant aspects that you should weigh in making your decision.
Installation Time (1 Day vs 3-7 Days)
The installation of gas boilers normally takes one day. This is very fast as this process primarily includes the connection of the boiler with the existing gas supply and heat system. The installation could be simply 4-6 hours in case of simple replacements.
Note: If you’re in Scotland, you may also be eligible for a boiler grant to reduce your installation costs.
On the other hand, the installation of an air source heat pump requires much more time, and the average time spent to install an air source heat pump is between 3-7 days.
This period is attributable to the fact that there is a need to:
- Install the outdoor and indoor units.
- Install or change the hot water cylinder.
- Install the system on the heating system of your home.
- Commissioning system and describing controls.
Initial Cost Comparison
The difference between the price of these heating systems is large. Typically gas boilers are between 2,750 pounds and 5,000 pounds with installations. Some of the factors that influence this price are the size of the boiler, its type, position and presence of extra pipework.
In the meantime, air source heat pumps are extremely expensive to invest in costing between 10,000 pounds and 22,000 pounds without grants.
Check out how much air source heat pumps really cost.
Government Grants
The Boiler Upgrade Scheme is a significant financial aid to promote the usage of low-carbon heating. Learn how the scheme helps homeowners switch from gas to green technology. Homeowners in the UK can receive 7,500 pounds towards an air source heat pump installation. This grant practically lowers the average cost to 5,000 pounds to 5,900 pounds and this varies according to the size of the property.
The scheme will be in operation up to 2028 and will enable heat pumps to be more affordable.
Find out more about the air source heat pump grant and how to apply.
Operation Costs and Effectiveness
Annual Use of Energy
The difference in the level of energy used in these systems is remarkable. The UK average household having a gas boiler consumes about 13, 600 kWh of gas per year to heat the home.
By comparison, air source heat pumps only need 4,000-5,000 kWh of electricity to provide the same heating, and this is mainly due to the fact that they use extra energy in ambient air.
Efficiency Ratings
Gas boilers: New A-rated condensing boilers have an efficiency of about 90 percent, that is, 10 percent of the energy is wasted as the flue.
Air source heat pumps: These are usually 300-400 percent (SCOP) efficiency, which provides 3-4 kilowatt-hours of heat per one kilowatt-hour of electricity used.
Intelligent Control
Both systems are currently providing more advanced smart controls. New boilers and heat pumps are also controlled through smartphone applications and they offer the ability to schedule, adjust the temperature and monitor energy consumption. In terms of maintenance, the maintenance of every system is to be conducted in a year in order to ensure efficiency and validity of warranties.
Lifespan
The average gas boiler has a lifespan of 10 to 15 years (with maintenance) and the heat pump has a much longer life-span (20 to 25 years on average). This long life span is what makes heat pumps more economical in the long run even though it has a higher cost at the start.
Key Takeaways
The question of which one to use: a gas boiler or an air source heat pump will always be up to you, your priorities, and your long-term plans. Despite the familiarity, cheaper initial investment, and shorter assembly time, gas boilers have a prospective option, the heat pumps, which have a high efficiency level and a better environmental impact.
Important: The other strong point of longevity is a point to consider when making your choice. The 20+ years life of a heat pump over a gas boiler 10-15 years implies that you are likely to change your gas system at least once throughout the working life of a heat pump.
This is due to the fact that a large percentage of the original cost is reduced by the long service life and low maintenance needs.
Environmental Impact: Heat pumps emit less than half as much carbon as gas boilers and this will decrease more as the UK electricity grid becomes more renewable in its sources. The heating system selection as such is thus a considerable individual input towards the carbon reduction objectives. Learn more about the effectiveness of air source heat pumps and their environmental impact.
Whichever of the two extremes you put into consideration, such as the low initial costs and familiarity or long-term performance and eco-friendliness, knowing these major differences would assist in the right choice of the heating solution that would satisfy the needs of your household as well as your visual perspective. Get a free quote today to explore options according to your budget
Frequently Asked Questions (FAQs)
Air source heat pumps are much more efficient with efficiency of 300-400% compared to the efficiency of 90% in gas boilers. This implies that the heat pumps have a potential of generating 3-4 units of heat per unit of electricity used.
The initial cost of heat pumps is more expensive between 10,000 pounds to 22,000 pounds whereas a gas boiler costs between 2,750 pounds to 5000 pounds. The cost difference is however narrowed by the UK government that provides a 7,500 pounds grant on condensate installations.
The environmental impact of heat pumps is much less and the emissions are approximately 850kg of CO2 per year as opposed to 2,200kg of gas boilers. The carbon footprint of heat pumps will continue to reduce as the electricity grid in the UK is made greener.
Heat pumps have a longer lifespan and typically have a lifespan of 20-25 years under good maintenance whereas gas boilers have a lifespan of 10-15 years under good maintenance. This increased life time is able to counter the increased cost of heat pumps in the short run.
