A Cooler Home: Where Should You Start?
UK summer heat can build up in homes through sunny windows, warm roofs, poor airflow and everyday cooking or appliances. A bedroom can become especially uncomfortable when it does not cool down overnight. You don't always need air conditioning: first stop unwanted heat entering the home, then let cooler air circulate when it is safe.
1. Keep sunlight out
Use outside shading if possible; close sun-facing blinds or curtains before the room gets hot.
2. Release heat safely
Open windows when outside air is cooler, often at night or early morning, where secure and safe.
3. Add cooling only if needed
Start with a fan for comfort. If the room is still dangerously hot, consider properly specified active cooling.
Pay extra attention to top-floor flats, rooms with large west- or south-facing glazing, poorly shaded bedrooms and homes where safe cross-ventilation is difficult. UKHSA's home-overheating checklist explains the risks.
1. External Awnings & Shading
What: Retractable awnings, external blinds, shutters, canopies and carefully positioned planting stop part of the sun's heat before it passes through the glass. This is often more effective at preventing solar overheating than relying only on inside curtains.
Best for: sunny patio doors, large west- or south-facing windows and rooms that become hot in the afternoon. Check whether the chosen product actually shades the glass at the time the room overheats — the sun's angle changes throughout the day.
Costs: A small exterior window canopy and a large motorised patio awning are very different jobs. Published UK price guides show roughly £700–£1,100 supplied and fitted for a basic 3 m manual awning, with larger motorised systems costing significantly more. Use this only as an initial budgeting illustration; obtain quotes for your wall construction, required fixings, access and electrical work. 2026 published awning cost examples.
Installation and limitations: Wind resistance, rain, wall fixings, safe retraction and access matter. External shutters or major canopies may need planning or conservation permission, especially in protected buildings and flats. Check whether your lease, landlord or management company allows the change.
2. Blinds & Curtains
What: Roller blinds, lined curtains, reflective-backed blinds and shutters reduce sunlight and glare entering a room. Close them before direct sunshine warms the space. Light or reflective surfaces can help, but effectiveness depends on the glazing, fabric and fitting.
Best for: an affordable first improvement, especially bedrooms and rented homes where exterior work is impractical. Blackout fabric is useful for light control, but does not automatically provide the best heat reduction.
Costs: For context, Checkatrade's June 2026 guide lists a medium roller blind at around £44 supply-only, with typical straightforward fitting around £20–£30 per blind. Made-to-measure, motorised and large-window solutions can be far more expensive. Published blinds pricing guide.
Practical tips: Choose adequate coverage around window edges and check child-safe blind cords. Avoid restricting required ventilation or blocking emergency exits. Combine blinds with nighttime ventilation for better results.
3. Ventilation & Airflow
What: Ventilation replaces stale or warm indoor air with outside air. Timing matters: if it is hotter outside than inside, opening windows can let extra heat in. Open them when outdoor conditions are cooler and it is safe to do so.
- Cross-ventilation: open secure windows on opposite sides of the home when outside air is cooler, where available.
- Night purging: ventilate during cooler evenings and early mornings, considering noise, security, insects and outdoor air quality.
- Roof and loft heat: ensure existing ventilation is not obstructed; get professional advice before altering roof or mechanical ventilation systems.
- Extract fans: use kitchen and bathroom extraction appropriately to remove humidity and heat produced indoors.
Costs: using existing windows may cost nothing, while replacing or installing fixed ventilation may require professional quotes. A portable fan can support airflow but is not a replacement for adequate background ventilation in a building.
4. Fans — Inexpensive Personal Cooling
What: Desk, pedestal, tower and ceiling fans move air across the skin to help sweat evaporate and make you feel cooler. Fans do not lower the room air temperature. Their motor adds a small amount of heat to the room.
Best for: everyday personal comfort, workspaces, bedrooms with tolerable temperatures and helping move air at cooler times. Look at noise, stability, child guards, oscillation and actual electrical wattage.
Purchase and running cost: Basic UK retailer examples include pedestal and desk fans around £35–£40, with premium products costing much more. A 50 W fan at an illustrative electricity rate of 26.32p/kWh costs approximately 1.3p/hour, or 10.5p for eight hours. Retailer examples.
Limits: When air is extremely hot, fans may not provide safe cooling. UKHSA recommends using electric fans if room temperatures are below 35°C, and warns against relying on fans directed at the body in very high heat. Follow official heat-health advice for vulnerable people.
5. Evaporative Air Coolers — Water-Based Cooling
What: These appliances pass air across water-moistened pads. Evaporation can cool the local airflow, but it also adds moisture to the air. It is not the same as refrigerant air conditioning, and should not be advertised as equivalent.
Best for: relatively dry, ventilated conditions and local relief. Less suitable: humid rooms, homes with damp or mould, and closed spaces where moisture accumulates.
Costs: A typical example consuming 80 W at 26.32p/kWh costs approximately 2.1p/hour, or 16.8p for eight hours. Purchase prices vary considerably with size and features; compare product-specific quotes rather than assuming water coolers match the temperature reduction of an air conditioner.
Maintenance: Clean, empty and dry the water tank and pads according to the manufacturer. Stagnant water can support microbial growth. Do not add inappropriate chemicals or operate a poorly maintained unit.
6. Air Conditioning — Active Room Cooling
What: Refrigerant-based air conditioners use a compressor and heat exchanger to remove heat from inside the room and reject it outside. Unlike fans, they can lower room temperature. There are two main domestic options:
Portable air conditioners
These stand inside the room and discharge hot air through an exhaust hose, normally fitted into a suitable window kit. The hose must vent outside: a so-called “portable air con” without a heat exhaust is usually an evaporative cooler, not true air conditioning.
Typical purchase illustration: Checkatrade's 2026 guide lists portable units around £350–£650 for different capacities; some cheaper or more expensive models are available. They need a suitable seal around the exhaust and can be relatively noisy. A single-hose model can draw warmer replacement air into the house.
Fixed split-system air conditioning
A wall-mounted indoor unit connects to an outdoor heat-rejection unit. It is generally quieter indoors and may be more efficient than a portable model for comparable cooling, but installation is specialist work. Some reversible air-to-air heat pumps can provide both cooling and heating.
Typical fitted example: Checkatrade reports approximately £750 for a 12,000 BTU/h wall-mounted unit plus about £1,150 installation, before any property-specific electrical extras. Ask for a fully itemised, VAT-inclusive quote — additional rooms, wiring, scaffolding and planning requirements can materially change the price. Published 2026 installation-cost comparison.
Choosing capacity: “12,000 BTU/h” is a cooling capacity, roughly 3.5 kW of heat removal. It is not the appliance's electricity input. Room size matters, but sun exposure, insulation, window area, occupants and heat gains also matter. Our advisor offers an early sizing reference, not a substitute for an installation heat-load survey.
Comparing Purchase Prices and Electricity Running Costs
Rather than giving unrealistic guarantees, use three pieces of information: purchase and installation price, electrical input in watts, and your actual electricity tariff. The simple examples below assume each appliance draws its stated input continuously. Actual air-conditioning compressors may cycle or modulate.
| Option | Indicative purchase or installation | Illustrative electricity input | 8 hours at 26.32p/kWh |
|---|---|---|---|
| External awning/shading | Example 3 m manual fitted awning ~£700–£1,100; quote other sizes | Usually none for manual shading | £0 |
| Blind or curtain | Example medium roller blind ~£44 before fitting | None for manual operation | £0 |
| Ventilation using existing windows | Often £0; building changes quoted separately | None if passive | £0 |
| Fan | Budget examples ~£35–£40 | 50 W | £0.11 |
| Evaporative air cooler | Product-specific retail quote | 80 W | £0.17 |
| Portable air conditioner | Published examples £350–£650 | 1,000 W | £2.11 |
| Fixed split air conditioner | Published one-room example ~£1,900 before extras | 700 W illustrative average | £1.47 |
Example rate 26.32p/kWh uses Ofgem's published GB average for October–December 2026 (check your bill; Northern Ireland prices and individual tariffs differ). Calculation: watts ÷ 1,000 × hours × price per kWh. Rounded to nearest penny. Purchase examples come from 2026 Checkatrade, UK retailer and awning price guides; they are not quotations or guaranteed savings. Fixed AC electrical power varies heavily with size, duty and conditions; the 700 W input is an illustration, not a product rating. Costs exclude existing household standing charges, servicing and non-electric consumables.
What about a hot month?
At the same rate, 8 hours a day for 30 days would cost about £3.16 for a 50 W fan, £5.05 for an 80 W evaporative cooler, or £63.17 for a continuously drawing 1,000 W portable air conditioner. The air-conditioner figure can change substantially with duty cycle, room heat gains and thermostat setting.
Summer Health, Installation Safety and Available Support
Keep people safe in a heatwave
Keep drinking fluids, avoid unnecessary exertion, stay in the coolest part of the home, and check anyone who may struggle to cool down — including older people, infants, pregnant people and those with relevant health conditions. If a home stays dangerously hot, use a safer cool space where possible and follow current NHS or UKHSA advice. Seek medical help for heat-related illness and emergency assistance for signs of heatstroke.
Electrical, water and refrigerant safety
- Use fans and portable coolers on safe stable surfaces; keep cables clear and avoid overloaded adaptors.
- Maintain evaporative cooler tanks, and prevent leaks or damp around electrical sockets.
- For fixed AC, confirm a suitable power supply, drainage, outdoor-unit positioning, noise and servicing arrangements.
- Work on regulated refrigerants must be done by appropriately F-gas-qualified individuals and, where applicable, certified companies. Do not attempt DIY pipework or refrigerant handling. Official F-gas rules.
Planning, building rules and neighbours
For external awnings and air-conditioning condensers, check local planning and conservation rules, structural fixings, neighbour noise and permission from the freeholder or landlord. In England, the government has stated that standalone cooling-only AC units do not have general permitted-development rights; qualifying air-to-air heat pumps have a different legal route. Scotland, Wales and Northern Ireland have their own requirements. 2026 Parliamentary answer on AC planning.
Grants and assistance
There is no automatic UK-wide grant for an ordinary portable fan, air cooler or room air conditioner. In England and Wales, the Boiler Upgrade Scheme currently includes £2,500 for eligible air-to-air heat pumps, subject to full scheme conditions and certified installation. This is not a general grant for every split AC unit. Ask an installer whether a proposed heating-and-cooling system qualifies before committing. Official grant terms.
For Scotland, Northern Ireland and Wales, check the relevant domestic-energy advice programmes for current local support rather than assuming a cooling appliance is funded. If your home creates an extreme overheating health risk — particularly in rented accommodation — contact the landlord or local authority housing service for advice. Meridian's Funding Hub provides other energy support information.
Safety, electricity-rate and scheme details reviewed 31 October 2026. Grants and regional rules may change. Official guidance takes precedence.
Common Questions About Cooling a UK Home
Should I open windows during a heatwave?
Only if it is cooler outside and safe to do so. On very hot afternoons, closing sun-facing windows and blinds can prevent more heat entering. Ventilate when the outside temperature falls.
Will a fan cool a room down?
No. It improves how cool you feel as air passes over your skin, but does not actively remove heat from the room.
Is an air cooler the same as air conditioning?
No. Evaporative coolers use water and add humidity; air conditioners use a refrigeration cycle to move heat outside the room.
Can I put ice in front of a fan?
It may provide limited local short-term relief, but it is not equivalent to air conditioning. Avoid water spills near electricity.
Is a portable air conditioner enough for a bedroom?
It may be, if properly sized, vented and maintained, but consider the noise, power demand and window exhaust seal before buying.
Are fixed air conditioners cheaper to run than portable ones?
Some are more efficient for the same cooling output, but the exact electricity use depends on the models, heat load and operating conditions. Compare rated input, efficiency and installation cost.
Do awnings actually reduce overheating?
They can be effective where they prevent direct sunlight from reaching glazing. The orientation, window shape and shade position matter.
Can I fit air conditioning in a flat or listed building?
Permission may be needed from the freeholder, management company and local planning or conservation authority. Check before ordering.
Do I need a professional to install split air conditioning?
Yes, refrigerant and associated electrical work must be carried out by suitably qualified professionals, with applicable certifications and permissions.
How do I compare my own running costs?
Use the appliance's rated electrical input in watts, expected hours, days of use and your own pence-per-kWh tariff in the Home Cooling Advisor below.
Try the Interactive Home Cooling Advisor
Answer a few questions about your room, see suggested starting points and compare indicative purchase, installation and running costs. You can adjust the electricity tariff, appliance wattage and usage period. Your input remains on this page.