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Curtain heater

Calculates the air flow needed for a curtain heater to prevent cold draft.

Curtain heater

Input Result
Opening width B=
Opening height H=
Air density outside ρu= kg/m3
Air density inside ρi=
Pressure difference ΔP= Pa
Wind speed v=
Gravitational coefficient g= m/s2
Flow coefficient Cd=
Wind direction coefficient Cv=
Air flow due to temperature QT=
Air flow due to pressure QP=
Air flow due to wind QV=
Total air flow Qtot=

Explanations

Opening width

Refers to the width of the current door or door where the curtain heater is located.

Opening height

Refers to the height of the current door or door where the curtain heater is located.

Gravitational coefficient

Refers to the earth's gravity at the place where the curtain heater is located.

Flow coefficient

A coefficient that is between 0.6 and 0.9

Wind direction coefficient

A coefficient between 0.5 and 0.6 in the wind is perpendicular to the opening and between 0.25 and 0.36 in diagonal wind direction.

Temperature outside

The temperature outdoors or the cold side of the curtain heater.

Temperature inside

The temperature indoors or the hot side of the curtain heater.

Air density outside

The density of the cold air.

Air density inside

The density of the warm air.

Pressure difference

Refers to the pressure difference between outside and inside. A curtain heater rarely manages to handle a pressure difference exceeding 5 Pa.

Wind speed

Refers to the rush of wind that any wind blows towards the opening.

Air flow due to temperature

The air flow needed to offset the temperature difference on each side of the curtain.

Air flow due to pressure

The air flow needed to offset the pressure difference on each side of the curtain.

Air flow due to wind

The airflow needed to offset the wind load against the curtain.

Total air flow

The total airflow on the curtain.

Formula

Air flow due to temperature: Air flow due to temperature
Air flow due to pressure: Air flow due to pressure
Air flow due to wind: Air flow due to wind
Total flow: Total flow