Part of WDI Group (Surrey) Ltd
Can air conditioning keep your Banstead home warm for less this winter?
Published 21 October 2026 by the WDI Group (Surrey) Ltd team
October is when the heating questions start coming in. If you already have air conditioning at a home in Banstead, Nork, Tadworth or Kingswood, you may already have a heating-capable system — many installations can warm a room as well as cool it, and in the right circumstances they can do so economically. Here is an honest look at how it works and when it makes sense.
Could your air conditioner already be a heat pump?
Many modern split air conditioning systems are reversible heat pumps — specifically air-to-air heat pumps. Check your model's manual or specification sheet to confirm it supports heating before you rely on it. In summer a reversible system moves heat from inside the room to the outdoors. In winter it runs the same refrigeration cycle in reverse, drawing heat energy from the outside air (even when it feels cold) and releasing it indoors. Because the system is moving heat rather than generating it, it can deliver several units of heat for each unit of electricity it consumes. The Energy Saving Trust has a good plain-English overview of air-to-air heat pumps if you would like the general background.
This is why the wall unit in your Banstead bedroom, loft conversion or garden office is not just for the two hot weeks in July. Used well, it is a year-round heating and cooling system.
When can heating mode cost less?
The clearest saving is against direct electric heating. Panel heaters, fan heaters and oil-filled radiators turn one unit of electricity into one unit of heat. A heat pump in heating mode typically delivers around two to four units of heat per unit of electricity, depending on the model and the outside temperature. If you are currently heating a garden office in Woodmansterne or a loft room near Banstead Downs with a plug-in heater, a correctly sized air conditioning system will usually heat that room for noticeably less electricity.
It can also be economical when you only need to heat the rooms you are actually using. Many of the 1930s semis and larger detached houses around Nork and Banstead village have rooms that sit empty most of the day. Warming a home office or a snug with its own unit, rather than firing the whole central heating system for one occupied room, can be a sensible way to cut waste.
We would not claim it is always cheaper than gas central heating — that depends on your gas and electricity tariffs, your boiler's efficiency, how well your home holds heat and how cold it is outside. What we can say is that for individual occupied rooms, and anywhere currently relying on direct electric heaters, heating mode is well worth using.
A worked example (hypothetical numbers)
To show how the arithmetic works — purely as an illustration, not a quote or a current tariff — imagine a small wall unit drawing 0.8 kW of electricity while heating, on a hypothetical tariff of 25 pence per kWh:
0.8 kW × 25p per kWh = 20p per hour of electricity input
That same unit might be rated to deliver around 2.5 to 3 kW of heat in mild winter conditions. The important point is that the rated heat output is not the electrical input — the heat output figure is the warmth delivered into the room, which is exactly where the heat pump's efficiency advantage comes from. Your real figures will depend on your own tariff, the model installed and the weather on the day, so treat this as an explanation of the maths rather than a promised running cost. For model-specific efficiency figures, the manufacturer's published technical data for the exact unit is the reliable source.
What affects the real running cost
- Your electricity tariff. The pence per kWh you actually pay is the single biggest factor in the hourly cost.
- Heat demand and insulation. A draughty room loses heat faster, so the unit works harder. Loft conversions and garden rooms with good insulation are where these systems shine.
- Outside temperature. Efficiency is highest in mild weather and gradually falls as it gets colder. On frosty Surrey mornings the unit will periodically run a defrost cycle to clear ice from the outdoor coil — this is normal and built into the system's operation.
- Correct sizing. An undersized unit runs flat out and struggles; an oversized one cycles on and off wastefully. This is why we size systems from a proper room survey rather than a guess.
Getting the most from heating mode this winter
- Select HEAT mode. On most remotes this is the sun symbol. If the unit is left in AUTO it may hesitate between heating and cooling on mild days.
- Set a sensible thermostat. Around 19–21°C is comfortable for most rooms. Each extra degree costs more to hold.
- Clean the filters. Dusty filters restrict airflow and reduce efficiency. Check and clean them as your unit's manual describes — usually a quick rinse every few weeks in heavy use.
- Keep the outdoor unit clear. Leaves, and later in the year windblown debris off Banstead Woods and the Downs, can collect around the outdoor unit. It needs free airflow to work efficiently.
- Let defrost do its job. A brief heating pause on a cold day can be normal defrost — let it finish rather than switching the unit off. Persistent cold air, or fault codes that stay on the display, need assessment.
- Book a service. A pre-winter service checks coils, airflow and drainage and can identify faults. Follow the manufacturer's servicing conditions for warranty cover.
One thing heating mode will not do is dry the air the way cooling mode does — dehumidification is a function of the cooling cycle, so if condensation is the problem, that is a separate conversation.
Is it right for your Banstead home?
If you already have a system installed, try the heating mode before you reach for a plug-in heater this winter — you may be pleasantly surprised. If you are considering a new installation, a system chosen for both heating and cooling gives you a warm garden office in January as well as a cool bedroom in July, from one neat installation.
We cover Banstead and the surrounding SM, KT and RH postcode areas, and every job starts with a free survey and a written quotation. If you would like advice on heating with an existing system, a pre-winter service, or a new installation sized properly for your rooms, get in touch.
This article is general guidance for homeowners. Running costs vary with your tariff, property and the weather; the worked example uses hypothetical figures for illustration only. Banstead Air Conditioning is a local trading website operated by WDI Group (Surrey) Ltd.