Smart Ways to Cut AC Costs This Summer

As summer approaches, UK households are bracing for higher energy costs. The energy price cap for a typical dual-fuel household is set at £1,849 per year from April to June 2025, marking a 6.4% increase from the previous quarter. Air conditioning (AC) usage can significantly contribute to these rising bills, especially during heat waves. However, by implementing proactive measures, you can reduce your cooling expenses and enhance comfort.

1. Understand the Cost of Running an Air Conditioner

Before diving into savings strategies, it’s essential to grasp the financial impact of using an AC unit. The average electricity price in the UK is approximately 27.03p per kWh. For instance, running a 780w portable AC unit for an hour would cost around 21p. While this may seem minimal, prolonged usage can lead to substantial costs over time.

2. Optimise Thermostat Settings

Even minor thermostat changes can lead to substantial improvements in energy efficiency. Increasing the thermostat setting from 72°F to 78°F during the summer can reduce cooling costs by 6% to 8% for each degree above 75°F. Additionally, utilising a smart thermostat allows for scheduling and remote control, ensuring efficient operation even when you’re away.

3. Enhance Home Insulation

Maintaining a comfortable indoor temperature relies heavily on proper insulation. Heat gain during hot weather can cause your AC system to work harder, increasing energy consumption. Improving insulation in walls, attics, and around windows can help keep cool air in and hot air out, reducing the load on your AC unit.

4. Seal Windows and Doors

Sealing windows and doors is a fundamental step in enhancing your home’s energy efficiency. Even minor air leaks can lead to significant energy loss, especially during the summer when air conditioning systems are in use.​

Effective Sealing Techniques

• Weatherstripping: This involves applying materials like foam, rubber, or felt to movable parts of windows and doors to prevent air infiltration. It’s particularly effective for sealing gaps around window sashes and door frames.
• Caulking: For stationary components such as the perimeter of window and door frames, caulking is used to fill cracks and gaps. Silicone or acrylic latex caulk is commonly used for this purpose.

5. Use Ceiling Fans

With ceiling fans, you can raise your thermostat by 4°F and still enjoy the same level of comfort due to improved air circulation. Ensure fans are set to rotate anticlockwise during summer to create a wind-chill effect.

6. Maintain Your AC Unit

Consistent HVAC maintenance of your air conditioning (AC) unit is key to maintaining peak performance and energy efficiency. Overlooking scheduled AC maintenance in the UK often results in greater energy use and higher operating costs.

Key Maintenance Tasks:

• Clean or Replace Filters Regularly: Dirty filters obstruct airflow, forcing the system to work harder. Regular filter maintenance—every 1 to 3 months—can greatly improve energy performance and air purity.
• Inspect and Clean Coils: When evaporator and condenser coils become dirty, they lose their ability to absorb and release heat effectively. Regular cleaning ensures efficient heat exchange. ​
• Check Refrigerant Levels: When refrigerant levels are low, cooling efficiency is compromised. An HVAC professional can evaluate and restore refrigerant to optimal levels.
• Clear Debris Around Outdoor Unit: Ensure the outdoor condenser unit is free from leaves and debris to maintain proper airflow. 

By adhering to these maintenance practices, you can enhance your AC unit’s efficiency, prolong its lifespan, and reduce energy costs.​

7. Utilise Natural Ventilation

Opening windows during cooler parts of the day allows fresh air to circulate through your home, reducing the need for air conditioning. By reducing reliance on mechanical cooling, this natural ventilation strategy can contribute to lower energy costs. Its effectiveness, however, is contingent on external elements such as weather conditions and air quality.

In areas with extreme temperatures or pollution, natural ventilation may not be beneficial. Therefore, it’s essential to consider local conditions when deciding to utilise natural ventilation. In the UK, where summer temperatures can vary, homeowners should assess the suitability of this approach based on their specific circumstances.

8. Implement Solar Shading

Implementing solar shading is an effective strategy to reduce indoor temperatures and minimise reliance on air conditioning. By installing blinds, shades, or reflective window films, you can block a significant amount of solar heat gain. Exterior shading devices like awnings or pergolas further enhance this effect by preventing direct sunlight from entering your living spaces.

These measures not only lower cooling costs but also improve indoor comfort by maintaining a more stable temperature. Incorporating solar shading into your home design is a sustainable approach to energy efficiency, especially during the warmer months. ​Installing blinds, shades, or reflective window films can block a significant amount of solar heat gain. Exterior shading devices like awnings or pergolas can also be effective in reducing indoor temperatures.

9. Upgrade to Energy-Efficient Appliances

Upgrading to an energy-efficient air conditioning (AC) unit can significantly reduce energy consumption and lower utility bills. Designed with cutting-edge technology, modern AC units boost cooling performance while lowering energy usage. By replacing older, less efficient models with newer, energy-efficient ones, you can achieve substantial savings over time.

Additionally, many energy-efficient AC units come with features such as programmable thermostats and smart controls, allowing for better temperature management and further energy conservation. Investing in an energy-efficient AC unit not only benefits your wallet but also contributes to a more sustainable and environmentally friendly home.

10. Explore Alternative Cooling Methods

Through the evaporation of water, evaporative coolers efficiently lower surrounding temperatures. This method is particularly effective in dry climates, where low humidity levels enhance the cooling efficiency.

By consuming significantly less energy than traditional air conditioning units, evaporative coolers offer an eco-friendly and cost-effective alternative for cooling indoor spaces. In humid environments, their performance declines because the air’s ability to absorb extra moisture is limited. Therefore, it’s essential to assess your local climate conditions before opting for this cooling solution.​

Conclusion

By taking proactive steps such as optimising thermostat settings, enhancing insulation, sealing air leaks, and maintaining your AC unit, you can significantly reduce your cooling costs this summer. Implementing these measures not only leads to financial savings but also contributes to a more sustainable and comfortable living environment.

Remember, small changes can make a big difference in managing your energy bills. Start planning and implementing these strategies now to enjoy a cooler and more cost-effective summer.