BIBLIOTECA HORTICULTURA

BIBLIOTECA HORTICULTURA

How to calculate the power of an industrial hot air generator?

How to calculate the power of an industrial hot air generator?

MET MANN explains how the calorific power of an industrial hot air generator should be calculated as well as some aspects to take into account when selecting the ideal equipment.

First of all we are going to define the minimum power of the industrial hot air heater, in order to determine this value, the volume of the industrial warehouse to be heated must be calculated.

For example, if we have a 600m2 warehouse and a height of 5m, the volume to be heated will be 3,000 m3.


Thermal differential
Once the volume of the industrial warehouse has been determined, we must consider the minimum comfort temperature according to regulations and depending on the activity, it must be between 14 ° C and 17 ° C, considering a minimum outdoor temperature of 0ºC and a target of 14 ° C, a thermal jump of 14 ° C is required.


Type of insulation of the premises
Finally, we must determine the type of insulation of the industrial building based on the following criteria

K = 1,5 The place is VERY WELL insulated. Walls or blocks insulated with fiberglass panels. Roof or insulated false ceiling.
 
K = 2,0 The place is WELL insulated. Brick walls or blocks without insulation. Insulated false ceiling or cover.

K = 2,5 The place is NORMALLY isolated. Brick walls or blocks without insulation. Cover not insulated.

K = 3,5 The place is NOT isolated. Board or fiber cement covers. Non-insulated cover


Final calculation
With all the data defined, the industrial air conditioning calculation formula is:

Volume x Thermal jump x Insulation = Necessary calorific power in kcal / h

3000 m3 x 14 ° C x 2.5 (type of insulation) = 105,000 kcal / h which divided by 860 kcal / h = 1 kW corresponds to 122 kW / h


Other aspects to consider:

    - Check that the type of industrial hot air generator to be installed is the most appropriate.
    - Determine if the user wants to set the whole installation or part of it.
    - Check if there are free heat sources (compressors, ovens, lights, etc.).
    - Class of work activity (depending on the activity, the comfort temperature is variable).
    - Location of the premises (an isolated warehouse is not the same as another paired one).
    - If the activity of the company involves constant door openings, the heat generated by the industrial hot air heater will dissipate increasing its consumption (to solve this problem it is advisable to install hot air curtains.
    - If the premises are for product storage, part of the volume will be occupied, so in principle a lower industrial hot air heater can be installed (this solution is valid for materials that are not good conductors of heat).
    - Check that the room does not have extractors in operation, in the winter stage (if there are extractors, take note of the extracted air flow and select an industrial hot air generator with enough flow to compensate for the air extraction).
    - Determine the position of the fuel tank (if its location is far from the equipment or at a lower level, a pressure group must be installed).
    - When the warehouse to be air-conditioned has a considerable height (+ 4m), it is advisable to install heat recovery destratifier fans on the ceiling, for example, the MET MANN model DVW140, in order to recover the stratified hot air on the ceiling, thus achieving significant energy savings (approximately 30%)
    - Install the hot air generator strategically, in order to cover the maximum surface area (not obstruct the air sucked in and driven by the equipment).
    - If the installation is carried out using a duct network, design it with the lowest possible pressure drop and with an optimal selection of grilles (air velocity in the duct 12 m / s air velocity in the grilles 5 m / s)


There may be other special variables but under normal conditions, performing this type of calculation we can fine-tune the thermal need for heating any type of industrial, commercial or agricultural premises with hardly any variations.