Heating, Cooling and Energy: Where the Money Actually Goes

Home energy spending is concentrated in a few places, and the order of what to fix is fairly consistent: stop losing heat first, control it second, generate it more efficiently third. Doing that in reverse is how people spend a lot for a small result.

Stop the losses first

These are the cheapest interventions and usually the highest return:

• Draught-proofing — gaps around doors, windows, letterboxes, floorboards and unused chimneys. Materials cost very little and the effect is immediate.
• Loft insulation to the current recommended depth. Heat rises, and an under-insulated loft is where most of it goes. Check the existing depth before assuming it is adequate — older installations are often well below current recommendations.
• Curtains and blinds, closed at dusk. Genuinely effective and free if you already have them.
• Hot water cylinder jacket, if you have a cylinder.
• Pipe insulation on exposed runs.

Ventilation still matters — sealing a home completely causes condensation and mould. Draught-proof deliberately, and keep trickle vents and extractor fans working.

Control it

• A programmable or smart thermostat, set to match when you are actually home.
• Thermostatic radiator valves, so unused rooms are not heated to the same temperature.
• Lowering the thermostat by a degree. One of the largest single savings available, and usually barely noticeable.
• Boiler flow temperature — many combination boilers are set higher than needed, and reducing it can improve efficiency noticeably. Worth asking about at a service.

Where the electricity goes

Heating things uses the most electricity: heating water, heating air, heating food. Devices left on standby are a small share, though not zero.

The heavy users in most homes are electric heating, tumble dryers, electric showers, kettles and ovens. Reducing use of those matters more than unplugging chargers.

A plug-in energy monitor tells you what your own home actually uses, which is more useful than general advice, and they are inexpensive.

Cooling

• Keep heat out during the day — closing blinds on sun-facing windows does more than most cooling equipment.
• Ventilate at night when outside air is cooler.
• Fans cool people, not rooms. A fan running in an empty room does nothing.
• Portable air conditioners need their hot air ducted outside properly, or they are close to useless. Check the noise rating and the running cost, which is significant.

Reading appliance ratings

Energy labels state annual consumption in kilowatt hours based on standard usage. Multiply by your rate to get a cost, then compare that plus the purchase price over the years you will keep it. Ratings have been rescaled in some markets, so compare consumption figures rather than letters.

Before you order

Check the loft insulation depth you already have before buying more. Check whether a smart thermostat is compatible with your specific heating system. Check the ducting requirement and noise rating on any portable air conditioner. And for anything involving gas, electrics or the boiler itself, use a qualified installer — in many places it is legally required as well as safer.