Air Conditioning Running Costs for Summer 2025.
We’ve put together a short article to help you understand the costs involved with running a modern air conditioning system in the UK in 2025. Here we based our calculations on the UK’s most popular house type (a 3-Bedroom Detached House) and made our calculations for the highest months of consumption (May–August). We hope you find this article helpful!
Our UK summers becoming increasingly warmer, more households are considering air conditioning as a practical solution for indoor comfort. However, many of you remain uncertain about the ongoing costs, especially in moderately sized properties such as a 3-bedroom detached house. This article breaks down the estimated daily running costs of air conditioning during the typical usage months of May through August.
1. Factors Affecting Air Conditioning Costs. The running cost of air conditioning depends on several variables:
- System type: Most UK homes use split-system air conditioning or portable units.
- Energy efficiency: Measured via SEER (Seasonal Energy Efficiency Ratio) or EER.
- Usage hours per day
- Electricity tariff: Averaging £0.28 per kWh as of 2025.
- Indoor and outdoor temperature differentials
- Home insulation and shading
2. Typical Usage Patterns (May–August)
| Month | Avg. Daily Use (Hours) | Temperature Range (°C) |
|---|---|---|
| May | 2–4 | 12–18°C |
| June | 3–6 | 15–22°C |
| July | 5–8 | 18–26°C |
| August | 4–7 | 17–24°C |
The hottest days may drive longer usage, particularly during heatwaves, while cooler or cloudy days result in little to no use.
3. Estimated Daily Running Costs. Assuming a split-system A/C unit with a 3.5kW cooling output and 1.2kW electrical input (a standard unit for medium rooms), here’s the estimated cost range:
| Month | Usage (Low–High hours) | Daily Cost Range (Low–High) |
|---|---|---|
| May | 2–4 hours | £0.67 – £1.34 |
| June | 3–6 hours | £1.01 – £2.02 |
| July | 5–8 hours | £1.68 – £2.69 |
| August | 4–7 hours | £1.34 – £2.36 |
These figures assume cooling in two main living spaces, such as a lounge and master bedroom. Running A/C in more rooms or using older, less efficient units would increase costs.
4. Total Summer Running Costs
By adding up estimated usage over the period we can see:
- Low-use total (May–August): ~£150–£180-
- High-use total (May–August): ~£280–£320
These costs represent an average and will vary by household habits, insulation, thermostat settings, and the number of cooled rooms.
5. Cost-Saving Tips
- Use smart thermostats to avoid overcooling
- Shut doors and windows to maintain internal temperature
- Run during off-peak hours if using time-of-use tariffs
- Pair with passive cooling like blinds, ventilation, and ceiling fans
Conclusion
While air conditioning does come with running costs—typically between £0.67 and £2.69 per day for a 3-bedroom detached home during summer—the benefits can far outweigh the expense. Beyond simply cooling your home, air conditioning offers a marked improvement in comfort, sleep quality, and productivity, especially during increasingly frequent UK heatwaves. It also helps control humidity, improving indoor air quality and reducing allergens like mould and dust mites. For families, older adults, or anyone working from home, having a controlled, comfortable indoor climate can significantly enhance daily wellbeing. With smart controls and energy-efficient models, it’s possible to enjoy these advantages without breaking the bank. Get a free no obligation air conditioning quote today.
Use our online air conditioning quote tool right here.