Why does my air conditioning feel cold in winter?

You switch the system on.
Heating is selected.
The room still feels cold.

This is a common frustration during winter. Many people assume their air conditioning is failing or unsuitable for cold weather. In most cases, the system is working. The issue sits in how heat is delivered, how the room reacts, and how the system is being used.

‍

Why air based heating feels different in winter

Air conditioning heats the air, not surfaces.

In winter, walls, floors, and furniture are cold. When warm air enters the room, those cold surfaces absorb heat quickly. This can make the space feel colder even though the system is adding heat.

The system is working.
The room is catching up.

The difference between feeling cold and being cold

There is an important difference.

A room can be warming while still feeling cold. This happens because moving air across skin increases heat loss from your body. Even warm air can feel cool when it first circulates in a cold space.

This effect is more noticeable in winter than summer.

Why the first 10 minutes often feel wrong

During the early stages of heating, the system focuses on stabilising itself.

Airflow may be gentle.
Heat output may be limited.
The fan may cycle slowly.

At the same time, cold surfaces absorb heat. This creates a delay between heat production and comfort.

After 10 to 15 minutes, the room should start to feel noticeably warmer.

Fan speed plays a bigger role in winter

Fan speed strongly affects how warmth feels.

Low fan speed can make the room feel cold because warm air stays near the unit. Medium or higher fan speeds distribute heat faster and reduce cold spots.

In winter, starting with a higher fan speed often improves comfort.

Why standing near the unit exaggerates the issue

Air leaving the unit may not feel warm straight away.

Standing directly under or in front of the unit makes airflow feel cooler due to air movement across skin. This does not reflect the overall room temperature.

Step back.
Give the room time.
Judge comfort after several minutes.

Auto mode increases winter discomfort

Auto mode allows the system to switch between heating and cooling.

In winter, this often causes problems. Sunlight, cooking, or body heat can raise local temperatures briefly. The system may respond by reducing heat or switching modes.

This creates uneven comfort and cold airflow.

Manual heating mode gives more consistent results.

Why raising the temperature does not stop the cold feeling

Increasing the temperature does not change how heat is delivered.

Air conditioning systems regulate output carefully. A higher temperature setting increases run time, not heat intensity. Cold surfaces and air movement still dominate early on.

Focus on mode, fan speed, and time rather than chasing the number.

Room factors that make winter heating feel weaker

Some spaces lose heat faster than others.

Common factors include
High ceilings
Large windows
Poor insulation
Open plan layouts
External walls
Frequent door opening

In these spaces, the system may need longer to overcome heat loss.

Common user actions that make rooms feel colder

These issues appear frequently during winter visits.

Low fan speed used continuously
Auto mode left active
Heating turned on and off repeatedly
Windows opened to check air quality
Timers switching the system off too early

Each one interrupts the heating process.

When cold feeling points to a real problem

Sometimes the feeling of cold reflects a genuine issue.

Possible causes include
System sized mainly for cooling
Outdoor temperatures limiting output
Incorrect unit positioning
Restricted airflow from dirty filters

These require assessment rather than setting changes.

When to seek professional support

Contact a specialist if
Heating mode is active for over 15 minutes with no improvement
The system cycles on and off constantly
Error codes appear
The outdoor unit does not operate

Before calling, note the model number, controller type, outdoor temperature, and how long the issue has been happening.

This speeds up diagnosis.

Related guidance

Further residential air conditioning guidance is available at
https://www.climateworks.co.uk/residential-air-conditioning

References

UK Government guidance on heat pump operation
https://www.gov.uk/guidance/heat-pumps-how-they-work

Building Regulations Approved Document L
https://www.gov.uk/government/publications/conservation-of-fuel-and-power-approved-document-l

ClimateWorks residential performance records from installations across Hampshire, Berkshire, Surrey, and Oxfordshire between 2022 and 2025

Author

Dr Julian Carter
Technical and Compliance Director
ClimateWorks

Dr Julian Carter has over 20 years of experience in building services engineering, air conditioning system design, and regulatory compliance. He advises on residential and commercial projects across the UK, covering system selection, installation standards, commissioning, and real world performance.

As Technical and Compliance Director at ClimateWorks, he oversees technical governance, installer training, fault diagnosis, and customer education. His work focuses on reducing user related issues, improving system reliability, and ensuring air conditioning systems perform consistently throughout their service life.

‍