What is Direct, Zone-Specific, Demand Controlled Ventilation?

a) Direct: Ventilation units are placed as close as you can get to where they are needed. Usually they are placed against an external wall of the room to be served, with simple penetrations through to the outside. Only short duct lengths are required, a far cry from the extensive supply and extract ductwork of centralised systems.Airmaster

b) Zone-specific: Each room or zone is given the appropriate level of ventilation, completely independently of what may be happening elsewhere in the same building. It would be possible, for example, for a demand controlled ventilation unit to shut down completely even though adjacent rooms may be experiencing high demand.

c) Demand Controlled: Sensors are used to measure, monitor and respond rapidly to changes of the indoor environment, according to the governing variable: either CO<₂ level, PIR movement sensor, humidity or timer control. The potential for energy saving is excellent.

Because they are placed within the room to be controlled, great care has been taken with the casing design of AirMaster air handling units. They are unobtrusive and segmented horizontally so as to blend in with ceiling lines. They can be mounted so as to be fully visible, or partly recessed in the ceiling void.

SAV Systems’ award winning AirMaster demand controlled ventilation units can be accommodated within suspended ceilings or attached to the ceiling slab.

Demand Controlled Ventilation Ensures Energy Savings and High Indoor Air Quality

SAV Systems’ AirMaster aims to provide consistently good indoor air quality over the long term. Although this objective is easily stated and understood, it can be challenging to achieve in practice. Here are the main issues which make the difference:
1. AirMaster is Equipped with high quality filters. This element is hugely important, not only to eliminating contaminants from the air itself, but also to the cleanliness of the heat exchanger surfaces. AirMaster units are equipped with filters to at least Class M5, which keeps the heat exchanger working efficiently. Had lower quality G Class filters been used instead, a progressive build-up of deposits could be expected on the heat exchanger surfaces, leading to a fall-off in performance.

2. Heat Exchanger Design. The aluminium contraflow heat exchangers utilised by the AirMaster air handling units have excellent conductivity, which enables the air pathway openings to be sized generously. Specific Fan Power and air pressure losses through the exchanger are therefore low. Condensate formed within the exchanger extract pathways is disposed of rapidly to the collection tray, leaving the air pathways clear even at low temperatures.
3. Minimised Noise Emissions. Noise can seriously detract from user experience. As direct ventilation units are in the same room as the people they are designed to serve, keeping noise pollution under control is crucial. AirMaster units at full throughput give out only 35dB(A) at 1m. There is no increase to this even after prolonged service, provided care is taken with filter changes.

AirMaster air handling units can be adapted in many different ways. They can be:

  • Fully exposed under the soffit, or recessed 1/3 or 2/3 into the ceiling void.
  • Placed against an exterior wall or connected to this by up to 8m ducting
  • Floor mounted for either mixing or displacement ventilation. The sides can be used as partitions, notice boards or sound absorbent barriers.
  • Arranged for modulating control of CO2, humidity or temperature. Alternatively, PIR displacement sensors can be used instead.

The importance of indoor air quality

Inadequate ventilation can lead to uncomfortable build ups of heat and carbon dioxide from occupants and equipment. Once carbon dioxide levels exceed 2,000 ppm, physical effects such as drowsiness and  impaired concentration become apparent. Efficient ventilation produces good indoor air quality, which in turn enables improved concentration, alertness and a sense of wellbeing.
The judges at the 2012 Heating & Ventilating Review (HVR) Awards recognised the significant advantages offered by AirMaster air handling units with heat recovery:

  • Appreciable energy savings
  • Effective demand control of indoor air quality at a local level
  • Low noise

SAV are happy to provide guidance for any application. With over 45,000 AirMaster demand controlled ventilation air handling units currently in service throughout the EU, there is a wealth of experience we can draw on. Whether for retrofits or new build projects, SAV can offer a view on good ventilation options for you to consider. Whatever level of project information is available to you, do get in touch to see how AirMaster might be able to help. We take pride in our practical, hands-on approach and technical support.

For further information on heat recovery ventilation systems, please contact us:

By phone:
01483 771910
By e-mail: [email protected]

We look forward to hearing from you!

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  • 1. AirMaster Brochure
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