Ventilation Systems - Ventilation Design, Evaporative Cooling, Process Cooling, Heat Recovery

Latest UK News: DELTA NEU boosting efficiency | Spotlight on ventilation | DELTA NEU welcomes first engineering apprentice

About Ventilation Systems

Ventilation Systems

Industrial ventilation systems are designed to improve the work place environment across industries from cereal manufacturing to can making and paper making to printing. Ventilation systems are used wherever there is a presence of heat, fumes or humidity and also where there is a need for air make-up to compensate for extraction systems themselves.

Ventilation System Design

Ventilation design techniques are based on two principal processes; extraction and input. Each of these is governed by good design principles, covering performance, effectiveness, energy consumption and treatment. Simple applications often use wall extraction Nylair fans or their derivative Extractair roof extraction units. These simple axial flow fans offer high air movements at low energy requirements simply passing air from the production area to the outside.

Simply extracting air takes away the warm or humid or contaminated air, but it is important to remember that for air to be extracted, it must be possible to enable replacement air into the area. Ignoring this means the area will operate under a negative condition and draw air in through any opening, doorway or gap in the building fabric. In food industries like breakfast cereal, that is understandably unacceptable as it is likely to cause the ingress of airborne pollution and insects: not great in your breakfast bowl! However, these high food hygiene standards apply equally to the food packaging industries such as carton and corrugated manufacturing but also to can making for food and beverage products.

Within the ventilation system design, the positioning of both the extraction and air input points can have a substantial influence on the performance of the system. Air movement can create as many 'draught' problems for any operators as it benefits the working environment. Positioning extraction points as close as practicable to the contaminant source, often reduces the amount of extraction required and prevents the contaminant having an effect over a broader area. Air input points should then be positioned to ensure a spread or air movement, rather than a localised condition.

Air input systems often require some form of treatment, starting with filtration to ensure a level of cleanliness to the air. However, a balance of cost, maintenance and cleanliness level is a major consideration. Generally speaking, the greater the level of filtration selected, then the higher the capital, operating and maintenance costs will be and probably the frequency of maintenance, as any filters collect the dust and pollution, and the higher the efficiency, the more they will collect.

Evaporative Cooling Systems

Econoclim

Evaporative cooling systems provide air cooling inside the workplace simply through the evaporation of water and evaporative cooling is the name given to the adiabatic process when applied to this ventilation technique. One should accept the principle that, in warmer weather, any production area will be at a temperature above that outside air temperature as a result of the internal heat load, irrespective of the ventilation level in use. This is because the energy used in electric motors, lighting and by the operators all results in a heat load on the area, increasing the temperature. Even with a significant amount of ventilation, this must result in a temperature rise.

The simplest way to offset this, is to provide an air input at a reduced temperature. Air conditioning is very often impracticable in manufacturing environments due to the large air volumes involved and hence high capital and operating costs. The alternative is evaporative cooling which, by evaporating a small amount of water into the air causes, under most conditions, a reduction in the temperature. Even in UK summer weather this reduction can be as much as 10oC at times, which can have a significant impact on the performance of the ventilation system. By inputting cooled air, the internal conditions can be maintained at temperatures at or below the outside ambient, even taking account of the heat gain inside.

The evaporative cooling technique is employed in the Econoclim product range and operates with very low running costs, using a small amount of water from a direct supply. The inherent design has added features making it a totally safe and reliable process ideally suited to manufacturing production areas across food, packaging and print industries.

Process Cooling Systems

These Ventilation and cooling techniques can be equally employed in process related applications. Electrical equipment has operating temperature limitations and simple Ventilation and evaporative cooling are regularly used to ensure reliability in electric motors, control cabinets and control rooms by limiting the temperature gain caused by the heat energy dissipated by the equipment.

Heat Recovery Ventilation Systems

Heat recovery, a further extension of the ventilation techniques, is employed to reclaim 'free heat' from hot process areas, electrical equipment and, probably the most significant, air compressors. In a typical compressor, 85% of the electrical energy is dissipated as heat which can be simply recovered and re-used as part of a ventilation system, transferring the heat to an area heating system in cooler weather conditions. In warmer conditions, the improved ventilation of the compressor usually results in a more reliable, more efficient operation.

Product Links

Econoclim

Nylair

Extractair

 

Sitemap | Accessibility

mail@delta-neu.co.uk | 0161 456 5511

French Flag International Site