Close Shutters at Night: How Much Do You Really Save?
A simple gesture that reinforces your window insulation.
Recommended Materials
- Shutters (rolling or swinging)
- Thick curtains
Steps to follow
Step 1
The physical principle: A window, even with recent double glazing, is the weak point of insulation (it is 5 to 10 times less insulating than a wall). At night, the temperature drops and the window becomes a cold radiator that sucks heat from the house. Closing the shutter creates a buffer air layer between the glass and the outside cold.
Step 2
The gain: Closing rolling or swinging shutters reduces heat loss through the window by 30% to 60%. It's huge. Over a heating season, this represents several tens of euros in savings.
Step 3
The right reflex: In winter, close the shutters as soon as night falls (around 5-6 pm), don't wait until you go to bed! That's when the cold falls. In summer, it's the opposite: close everything during the day to keep the cool.
Step 4
The winning combo: Closed shutter + Thick curtain inside. The curtain cuts the sensation of a cold wall and prevents the warm air of the room from licking the cold glass. Choose curtains with a thermal lining for maximum efficiency.
Step 5
Automation: If you have electric shutters, domotize them (see dedicated guide). Program an automatic closing 'At sunset'. It is the best way to never forget and maximize savings.
Frequently Asked Questions
Louvered shutters ?
They are less effective than solid shutters because air circulates through them, but they still break the wind and protect the glass from the cold radiation of the night.
Precautions
- Do not trap curtains in radiators.
- Ventilate anyway 5 min per day.
