November 2016

VAV Control System

Normally when you use a centralised Mechanical Ventilation with Heat Recovery (MVHR) unit to ventilate an office, a block of flats or a school, the ventilation rate has to remain the same in each room of the flat or office regardless of occupancy levels between the rooms. Conversely the ventilation rate may be unable to quickly adjust to increases in occupancy or high usage, such as cooking, bathing or hosting parties, and result in poor air quality within the property. Constant human interference would be required to maintain the level of comfort in these situations.

However, there is a system, when used in conjunction with a centralised MVHR unit, which gives you the opportunity to maintain a consistently high quality indoor air environment in the office, flat or classroom: Variable Air Volume (VAV) dampers.

Typically VAV dampers are used to adjust the ventilation rate based on the air pressure in the system. However, this can cause additional undesired noise caused by the closing of the damper in the pressure based system as there be a long delay for the MVHR unit to adjust the VAV damper configuration. Furthermore there will be a delay when the ventilation rate needs turning up, meaning that there will be substandard air quality in the room for an extended period of time. Furthermore, these systems can have a possible negative impact on the unit’s energy efficiency and lead to a reduction in the life of the fan’s motors, as there is constant adjust taking place as the unit tries to deliver the required air flows at the desired system pressure.

However Airflow units use a different system. The VAV damper systems used in our Adroit Pro and commercial Duplexvent ranges use dampers that react to changes to the air volume passing through them. Airflow’s VAV system, unlike many others, offers an automated alternative that maintains a comfortable level of ventilation even when demand is different between rooms, flats, offices etc. Airflow’s VAV does offer manual adjustment should the user want to still maintain some level of control.

The system constantly measures the air volume supplied and shares this information with the centralised unit . This direct communication ensures the unit to react to even the smallest change in ventilation demand quickly and efficiently. This minimises the time delay in guaranteeing the correct ventilation rate is taking place to the property/room but also minimises noise and maintenance costs and increases the energy efficiency, life cycle of the system. The communication between each damper and the unit allows the ventilation to increase/decrease based on the demand required.

When used in conjunction with a humidity or CO2 sensor, these dampers can be used to automatically boost and reduce the ventilation based on the usage or occupancy of that room without affecting the air quality in the other flats or rooms within the building.

Duplexvent Rotary

Airflow are proud to announce that we have introduced a new outdoor line to supplement our hugely successful Duplexvent Rotary MVHR range: the Duplexvent Rotary-N.

The Duplexvent Rotary-N are all-purpose rooftop units that can improve the indoor air quality of various different commercial premises such as schools, restaurants, office blocks and warehouse whilst protecting the health of those working within the building as well as the fabric of the building itself. The compact design of the Rotary-N allows for a discrete installation and helps you to maintain an aesthetically pleasing design of the premises.

The Duplexvent Rotary-N helps to reduce the property’s energy costs thanks to its highly efficient rotary heat exchanger that can recover otherwise wasted heat energy and use it to pre-warm the incoming filtered, supply air. This means that the building’s heating isn’t warming the workplace as much as normal and in turn can reduce the energy bills of the property. This brand new range comes in 7 different models and is able to extract from 1550m3/hr (431 l/sec) to 16700m3/hr (4639 l/sec) with impressive sound levels from just 34dB(A).

Following on from the launch of our new Duplexvent Rotary-N range of commercial MVHR units, Airflow have also expanded our range of the existing Duplexvent Rotary range of compact, indoor commercial MVHR units with rotary heat exchangers.

With 7 units from you to choose from, there’ll be something to meet your ventilation needs. They are ideal for schools, offices and halls and will improve the quality of air circulating through property. The Rotary range can supply up to 16700m3/hr (4639 l/sec) from an unnoticeable 34dB(A).

All Duplexvent Rotary and Rotary-N units can filter out small airborne pollutants such as pollen or dust thanks to the unit’s ability to be fitted with G4, M5 or F7 air filters. This helps to maintain a healthy indoor air environment for those within the building. By maintaining a healthy indoor air environment, you protect from indoor air pollution, which research shows can affect productivity, concentration levels and in worst cases even cause severe health problems.

All units have 85% thermal efficiency thanks to the highly efficient rotary heat exchanger. Duplexvent Rotary units can be fitted with G4, M5 or F7 filters. The units adhere to the current ErP Ecodesign Directive requirements including the stricter, draft 2018 regulations. Furthermore, they help you achieve Passive House approval, thanks to their extremely low SFP values of less than 0.45W per m3/hr. Each model has T2 level insulation, an integrated web server and a sophisticated yet user friendly control system.