A north-facing room usually has a lower solar load than the same room facing south, so the air conditioner can be smaller. It can still overheat from people, computers, a kitchen next door, or heat drifting from a landing. Survey it anyway. Do not skip the visit because the room feels fine in April. Size the hot afternoon you actually dislike, then pick a 230 V reverse-cycle split and a lawful outdoor position.
Gentler glass, and heat that is still in the room
North light is valued because it is even, and the cooling peak from the glass is gentler. Internal gains remain: two people working, a desktop computer, lamps, and a closed door that traps heat. A north kitchen still has the hob. Expect a smaller solar gain, then prove it. Include occupants and equipment.
Tell the installer the room faces north and what time of day it feels worst. The answer might be modest cooling plus a better blind on a roof window you had forgotten to mention.
A small north bedroom should stay a small split
A small north bedroom is a common 2.0 or 2.5 kW split. Jumping to 3.5 kW because that is what the living room has will oversize it. Oversized units in small rooms short-cycle and handle humidity poorly. The saving belongs on the correct kW and a value or quiet indoor to match how you sleep, not on deleting the survey fee.
Winter on a wall that never sees sun
North rooms lose sun in winter and are often the ones that feel dank. Winter heating can matter more on a cold north wall. A reverse-cycle unit, the air-to-air heat pump Energy Saving Trust describes, can warm that room without running every radiator. Check output at low outdoor temperature.
Cooling and heating share the same pipes and the same outdoor unit. The install cost is mostly already there once you decide the room needs either function.
Frequently asked questions
Can I skip a survey because the room faces north?
No. Solar gain is lower, and people, equipment and heat from other rooms can still justify a unit. The survey stops you buying the living-room size by habit.
Are north-facing bedrooms easier to cool?
Often yes, compared with a south bay of the same size. Many still want a small split for hot nights. Confirm the kW rather than assuming zero.
Is heating more useful than cooling on a north wall?
Sometimes. Price a reverse-cycle unit and read the heating table if the room is cold all winter and only occasionally too warm.
What if the door to a south-facing diner stays open?
The load leaks through the opening. Say how you use the doors. A survey of the north room with the door imagined shut will be wrong if the door is always open. Watch borrowed heat from hotter rooms.
Does a smaller outdoor unit skip planning or F-gas?
No. A smaller outdoor unit is easier to place and usually quieter, and it still needs airflow, a drain for its own condensate in heating, and a legal position. In England, use the Planning Portal conditions. F-gas rules are the same at 2.0 kW as at 5 kW.
Core buying guides
Start with these high-intent guides, then dig into the rest of the library.
Related guides
Sources and further reading
How this guide was prepared
This guide was written by the Local AC Installers Editorial Team. We compare official guidance, legislation and established consumer information, separate general information from project-specific advice, and show publication dates and sources. We do not accept installer accreditation claims at face value.