The short version: air source offers similar performance for significantly less system cost and...
When considering the benefits of air-source heat pumps (ASHPs) over gas or oil boilers, one aspect that stands out is their positive impact on local air quality. Unlike fossil-fuel boilers, which rely on the combustion of fossil fuels, air-source heat pumps operate using electricity to harness and intensify the energy that is abundant in the local environment. This difference has significant implications for the air we breathe, particularly in densely populated urban areas.
Elimination of Combustion Emissions
Traditional boilers, whether they run on fossil gas or heating oil (kerosene), produce emissions as products of combustion. Waste gases and particles are then released into the environment through the exit flue. The most concerning of these are nitrogen oxides (NOx), sulphur dioxide (SO₂), carbon monoxide (CO), and particulate matter (PM). These pollutants contribute to a range of health problems, including respiratory issues, cardiovascular disease, and premature death.
No smoke without fire. Combustion is the source of many harmful gasses and particles in the home.
In contrast, air-source heat pumps do not produce any on-site emissions since they don’t burn fuel. Instead, they work by transferring heat from the outside air into the building. This means that the use of ASHPs directly eliminates the local emission of harmful pollutants, leading to cleaner air in and around homes and buildings equipped with these systems.
Improving Urban Air Quality
Urban areas, in particular, stand to benefit significantly from the widespread adoption of air-source heat pumps. Cities often suffer from poor air quality due to the high concentration of vehicles, industrial activities, and residential heating systems that rely on fossil fuels. In fact, residential heating is a significant contributor to air pollution in many cities, particularly during the colder months when heating demand is high.
By switching from conventional boilers to air-source heat pumps, urban areas can reduce one of the key sources of local air pollution. This is especially important in areas where air quality is already compromised, and where regulations on emissions are becoming increasingly stringent. The reduction in emissions can lead to measurable improvements in public health, decreasing the incidence of pollution-related illnesses and reducing the strain on healthcare systems.
Improving Indoor Air Quality
In addition to improving outdoor air quality, air-source heat pumps (ASHPs) also have a positive impact on indoor air quality. Traditional boilers, especially those that rely on fossil fuels, can pose indoor air quality concerns. For instance, gas or oil boilers can sometimes lead to indoor pollutants such as carbon monoxide (CO) and nitrogen dioxide (NO₂) if there are issues with ventilation or if the equipment is not properly maintained (at a minimum, a thorough annual service). These pollutants can accumulate indoors, posing serious health risks including headaches, dizziness, and even life-threatening conditions in the case of carbon monoxide poisoning.
Air-source heat pumps, however, do not involve combustion, thus eliminating the risk of these dangerous indoor pollutants. By operating without burning fuel, ASHPs ensure that the air circulated within the home remains free of combustion byproducts related to space heating and hot water.
To fully address indoor air quality concerns, consider how food is cooked. Gas hobs and ovens can also be a source of indoor pollutants - special attention should be given to proper ventilation and extraction. Consider changing to electrified cooking. Electric ovens are the standard these days, whereas gas hobs remain popular with many householders. Induction hobs are gaining popularity and offer an experience that is arguably superior to a gas hob in terms of controllability and ease of cleaning. Once a heat pump is installed in a property a homeowner can also switch to an induction hob and fully eliminate those harmful pollutants from their home (and their gas standing charge!).
Contribution to Broader Environmental Goals
Beyond the immediate local benefits, the reduction in emissions from residential and commercial heating also contributes to broader environmental and public health goals. For instance, the European Union and many other regions have set ambitious targets for reducing air pollution and greenhouse gas emissions. Transitioning to air-source heat pumps is aligned with these goals, as they can significantly lower the overall carbon footprint of heating systems.
Noise Considerations
Air-source heat pumps installed in residential areas have an often cited nemesis: noise. The external unit of an ASHP, which houses the compressor and fan, produces audible sounds during operation - all units have a manufacturer tested and declared sound pressure level in decibels.
Nuisance noise has been a genuine concern in quiet residential areas or in situations where the unit is placed close to windows or neighbouring properties.
The good news is that advancements in heat pump technology have led to the development of much quieter models, and careful selection of installation positioning actively mitigates noise concerns in line with MCS installation standards and local planning requirements. Positioning the unit away from sensitive areas, using noise-dampening mounts, partial screening and regular maintenance all help mitigate any disturbance related to audible noise.
Noise is no longer a real issue with correct specification and installation. All Fornax supplied heat pumps are carefully specified, installed and maintained to ensure that noise will never be an issue.
Conclusion
The transition to air-source heat pumps from conventional boilers offers significant benefits for local and indoor air quality. By eliminating the need for combustion, ASHPs reduce the emission of harmful pollutants that contribute to respiratory and cardiovascular diseases, particularly in densely populated urban environments (and in homes) where air quality is a pressing concern. This makes air-source heat pumps not only a smart choice for individual homeowners but also a critical tool in the broader effort to improve public health and achieve environmental sustainability.
