What temperature is actually needed in a bathroom?(and why is it different from other rooms?)

🟧 1. A bathroom is not a “regular room”

A bathroom is one of the most specific spaces in a home.

Several factors come together here at the same time:

• high humidity

• rapid temperature fluctuations

• direct contact with water

According to CIBSE:

the recommended temperature is:

22°C – 26°C

That is already higher than in most other rooms.

🟧 2. Human physiology changes comfort

In a bathroom, comfort is determined not only by the room itself, but also by the human body.

• no clothing

• wet skin

• rapid cooling after a shower

According to ASHRAE:

• humidity + skin condition significantly increase heat loss

🟧 3. Comfort = operative temperature

According to ASHRAE 55:

Comfort is determined by:

• air temperature

• surface temperature (MRT)

Approximately 50% / 50%

This means:

• You do not feel the air alone — you feel the walls, the floor, and the mirror

🟧 4. The main problem — cold surfaces

Even at +24°C, a bathroom can still feel uncomfortable.

• cold tiles

• cold walls

• mirror condensation

What happens physically:

• the body radiates heat toward cold surfaces

• -this creates a sensation of cold

  
  

🟧 5. Infrared radiation — especially suited to this space

This is where the fundamental difference appears.

Convection:

• heats the air

• surfaces remain cold

• comfort is delayed

• Infrared radiation:

• heats surfaces and objects

• increases MRT

• reduces condensation

The result: comfort at the same — or even lower — air temperature

🟧 6. Thermostat + smart control = real savings

A bathroom is not used 24/7.

In reality, it is mainly used:

• in the morning

• in the evening

• in short intervals

This means:

• there is no need to maintain 24°C all day long

With a thermostat:

a lower temperature can be maintained (for example 18–19°C)

and raised only before use

🟧 7. Fast warm-up time — a critical advantage

This is where infrared heaters clearly stand out.

Warm-up time: ~5–7 minutes

This means:

the room does not need to be kept warm all the time

comfort is reached quickly, exactly when it is needed

switch it on → comfort is felt within minutes

🟧 8. The logic of energy savings

With traditional heating:

• a constant temperature must be maintained

• heat losses continue all day long

With infrared heating:

• you can operate on demand

• operating time is shorter

• the average temperature can be lower

This gives you:

🟧✓ lower electricity consumption

🟧✓ lower energy bills

🟧✓ greater control

🟧 9. A practical model

Standby mode:

17–19°C

Before use:

22–24°C (switch on 5–10 minutes beforehand)

After use:

automatic return to a lower setting

Conclusion

• A bathroom requires a higher level of comfort

• Comfort is determined by surfaces, not just by air

• A thermostat can significantly reduce energy consumption

• Fast warm-up time = shorter operating time

💥 An infrared heater allows you to maintain a lower temperature while achieving higher comfort

The key idea

💥 Comfort is not what the thermometer shows.

Comfort is what a person feels.

🟧 CTA

For projects where comfort, energy efficiency, and a stable indoor environment matter,

it is worth looking at and comparing infrared heating solutions in practice.

🟧 The Sundirect approach

100% heat to you. Not the air.

📚 Sources

CIBSE — CIBSE Guide A: Environmental Design

ASHRAE — ASHRAE Handbook – Fundamentals

ASHRAE 55

ISO 7730

Mean Radiant Temperature (MRT)

Radiant Heating Systems