# Temperature control

##### CALCULATION OF TEMPERATURE CONTROL IN ENCLOSURES

What’s needed:

1. The dimensions of the enclosure (height, width, depth) [m]
2. The enclosure position (eg. single enclosure in row) according to calculation formula, enclosure surface area A [m²]
3. The enclosure material (metal, plastic) heat transfer coefficient from table, k [W/m² K]
4. The temperature difference between desired enclosure interior temperature Ti [°C] and the expected ambient temperature Tu [°C] (eg. day – night, summer – winter, climate zones) ΔT [K=Kelvin]
5. The stray power (self-warming) of all installed components during operation (eg. transformers, relays, semi-conductors) Pv [W]

Calculation and selection of parameters: enclosure surface area – heat transfer coefficient – temperature difference

 Single enclosure free on all sides A = 1.8 x H x (W + D) + 1.4 x W x D Single enclosure, wall mounted A = 1.4 x W x (H + D) + 1.8 x H x D First or last enclosure in free standing row A = 1.4 x D x (W + H) + 1.8 x W x H First or last enclosure in wall mounted row A = 1.4 x H x (W + D) + 1.4 x W x D Middle enclosure in free standing row A = 1.8 x W x H + 1.4 x W x D +D x H Middle enclosure in wall mounted row A = 1.4 x W x (W + D) + D x H Middle enclosure in wall mounted row with covered top A = 1.4 x W x H + 0.7 x W x D + D x H topp To calculate the effective temperature we use the formula:

 Teff = 33 (10x√v-v+10.45)(33-T) 22.066