Medium Density Housing Ventilation Systems

Ventüer is a company that specialises in design and manufacture of ventilation systems to suit your housing or MDH projects. They have systems available to suit a range of MDH options, from two or three-storey townhouses right up to multi-storey, multi-unit apartment blocks. Ventüer engineers and manufactures ventilation products, designs them to integrate with project-specific details and guarantees them to comply with New Zealand Building Code requirements while creating healthy and comfortable indoor spaces. Each Ventüer solution is different but based around some important basic principles.

The Ventüer MDH ventilation systems are comprised of three categories: MVHR (mechanical ventilation with heat recovery), BPV (balanced pressure ventilation) and MEV (mechanical extract ventilation).

Due to the additional complexity of MDH projects as compared to traditional standalone houses, standard ‘ventilation kits’ as sold by many electrical wholesalers are not suitable for use on these developments.

There are numerous variables that affect the final design of MDH ventilation system, such as:

• Structural design methodology — how the midfloors, external walls, internal walls, and roof will be constructed all have an impact on the size, shape and type of ductwork that must be used.
• Inter-tenancy acoustic requirements and fan locations will determine the type of fans that can be used.
• Additional attenuation, for example duct silencers, may also be required.
• The passive fire design requirements may necessitate the integration of fire dampers and collars into the ventilation system design.

Ventüer MVHR (mechanical ventilation with heat recovery) MVHR is the ‘Rolls Royce’ of residential ventilation systems. It runs continuously, drawing stale and moist air from within the dwelling and replacing it with filtered outdoor air. The supply and exhaustair streams are passed over each other through a heat exchanger, transferring a large percentage of the heat in outgoing air to the cooler incoming air. This heat exchange can significantly reduce the required heating load of the building, driving down operating costs and increasing energy efficiency.

MVHR systems are particularly suited for colder climates where heating is of increased importance, however, they can also offer value and a demonstrable return on investment in warmer zones as well. As they require no opening doors or windows, they are also ideal for noisy sites such as projects located near motorways and under flight paths.

Ventüer BPV (balanced pressure ventilation)
BPV provides guaranteed mechanical ventilation at reasonable cost. Extraction fans draw stale and moist air from the building, and a separate supply fan brings in outdoor air. Balanced pressure systems ensure suitable ventilation by drawing out the same amount of air that is brought in, thus ensuring proper air change. They should not be confused with positive pressure or negative pressure systems which either supply or extract air only and rely on leakage in the building façade to equalise the pressure and allow the air to be changed. BPV systems are a low-cost alternative to MVHR systems, however do not provide the same ongoing energy savings. They are also simpler to design and take up less space than MVHR systems.

Ventüer MEV (mechanical extract ventilation)

MEV is the traditional method of ventilating New Zealand homes. Fans in the bathroom, laundry and kitchen are used to extract moist air and kitchen fumes. Ventilation of bedrooms and living spaces occurs naturally via opening door and windows. Whilst this method of ventilation is the lowest cost and simplest to design, it comes with several drawbacks:

• There is no ability to recover heat from outgoing air streams.
• The layout of the building may limit the number of openable windows and doors.
• Ventilation of indoor spaces is entirely dependent on natural wind action, and calm days may result in low ventilation rates.