NSW: Q&A Improving Efficiency of Carpark Ventilation Systems

This Q&A article is about car park ventilation.

Table of Contents:

• QUESTION: To save electricity, the strata committee decided to switch off the ventilation system. The building now falls below the Australian Standards.
• QUESTION: A lot owner’s storage cages partially block the car park exhaust vents, effectively changing the design of the car park ventilation. Can the Owners Corporation insist this is removed?
• ARTICLE: Carpark Ventilation

Question: To save electricity, the strata committee decided to switch off the ventilation system. The building now falls below the Australian Standards.

The strata committee chair has decided to switch off the fans that form part of the ventilation system for both the garage and the residential floors. Their view is that this will save electricity.

The air conditioning firm manager contacted me last week to inform and say that as a result of this economy the building falls below the Australian Standards. The committee dismisses this view. Is this a local council issue? Can a building be forced to comply with the relevant Australian standard?

Answer: Unless expert advice has been obtained that would permit the fans to be turned off, the committee is taking on serious liability.

In my view this is a breach of statutory obligations on the part of the strata committee and there is liability attached in the issue. These might be minor in their view, however the potential consequences that could come such as mould infestations or excess levels of poisonous gasses in the garage or other areas.

Unless expert advice has been obtained that would permit the fans to be turned off, the committee is taking on serious liability.

Andrew Terrell
Bright & Duggan
E: [email protected]

This post appears in Strata News #486

Question: A lot owner’s storage cages partially block the car park exhaust vents, effectively changing the design of the car park ventilation. Can the Owners Corporation insist this is removed?

A lot owner in our strata of 5 lots has built 2 cages in the shared garage.

Their parking spaces are on title however the storage cages and their contents partially block the car park exhaust vents in the ceiling of the parking garage which discharge through concrete vents in the common property yard. This effectively changes the design of the car park ventilation.

Can the owners corporation insist the obstructing storage cages be removed?

Who is liable if there’s an exhaust event in the garage?

Answer: The construction might be illegal and removal can be insisted by the owners corporation.

Tracey: Our experience has been that you can insist that anything compromising air flow be removed. Ventilation and air flow must be in accordance AS 1668.2.

Tracey Wyber
Trackie Industries
E: [email protected]

Andrew: Was the construction of the cages subject of a by-law and general meeting approval? If not, the construction might be illegal and removal can be insisted by the owners corporation.

Whether the owners corporation can insist they be removed will be subject to whether approval was given by the owners corporation in the first place.

Ideally (even if approval was provided), the committee would meet with the owner to negotiate on the issue. In similar circumstances, I have seen this resolved by ensuring that items are only stored within a certain height within the cage and that a by-law stipulates a right of access by the owners corporation for the purpose of maintaining fire control/ventilation.

Andrew Terrell
Bright & Duggan
E: [email protected]

ARTICLE: Carpark Ventilation

Carparks that are not adequately naturally ventilated must be mechanically ventilated.

Ventilation systems usually consist of exhaust and supply fans with large power ratings.

Many car park ventilation systems are either running at full speed, are turned off, or operating on timers during perceived “peak periods”. The first approach imposes a significant energy cost and the latter two can compromise occupant health and safety.

Relevant Standards for Carpark Ventilation Systems

The National Construction Code (NCC) requires that every storey of a carpark, except an open-deck carpark, must have:

• a system of mechanical ventilation complying with AS 1668.2: The use of ventilation and airconditioning in buildings – Mechanical ventilation in buildings; or
• a system of natural ventilation complying with Section 4 of AS 1668.4: The use of ventilation and air conditioning in buildings – Natural ventilation of buildings

The primary requirements are:

Carpark ventilation systems must operate at all times unless they are automatically controlled by a carbon monoxide (CO) monitoring system

The system must also provide at least 1 air change in every 24 hr period

• The levels of CO that will trigger the operation of the system vary depending on whether the car park is occupied or not. For example, if a building manager’s office is located in the car park, the system will trigger at a lower CO concentration level
• If the system has automated controls, car park ventilation rates can vary depending on the concentration of CO detected (see Variable Speed Operation below)
• No point in the car park can be more than 25m away from a sensor
• Additional energy saving measures are permitted for small car parks – 40 or fewer car spaces (see Small car parks section below)
• The systems must be serviced twice-yearly

There are some variations in the standards that are best interpreted and assessed by a qualified service provider.

Variable Speed Operation

Since car park fans are very power hungry, variable speed drives can make a significant difference to the power consumed. The standards provide for the fans to operate at different speeds, depending on the level of CO detected by the sensors.

Ventilation rates vary according to the concentration of CO detected in relation to the system’s configured CO exposure limit (EL) – the concentration of CO that triggers fan operation:

• At 75% of the EL and above, the system runs at the full ventilation rate
• Between 50% and 75% of the EL, the system operates at a variable ventilation rate as defined in the standard
• Below 50% of the EL, the system can operate at 25% of full ventilation rate
• Below 25% of EL, intermittent ventilation is allowed
• The system can turn off below 15% of EL and restart again at 25% of full ventilation rate when 25% of EL is reached

NOTE: There is a cubic relationship between fan speed and power consumption i.e. if the fan speed doubles, power consumption increases 8-fold, and vice-versa.

Small Car Parks

For car parks with 40 or fewer car spaces, energy saving measures additional to a variable speed operation are allowed.

The airflow rate can be halved if all vehicles remain parked and engines don’t operate for more than 2 hours. If the car park is also unoccupied at the same time, the system can be shut down. The system can be reactivated by motion detectors in doorways and lift doors and whenever vehicle entrance doors are opened.

Potential Cost Savings from the Right Carpark Ventilation

• Decreased operational costs through reduced energy consumption – any reduction in speed results in significant energy savings
• Peak Demand cost savings – installing VSDs reduces peak demand by removing the high surge currents of power associated with starting fans at full speed
• Maintenance cost savings – a softer start at lower speeds reduces wear and tear on the equipment

Christine Byrne
Green Strata

This post appears in Strata News #263.

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Read More:

• NSW: Q&A Fined by the OC for moving bins that were blocking my parking space!
• NSW: What’s the Importance of Good Ventilation in Your Building? [Case Study]
• Changes in Legislation to Annual Fire Safety Statements NSW

Are you interested in more information about carpark ventilation or strata legislation in your state or territory? Visit Apartment Living Sustainability, Maintenance and Common Property OR Strata Information Pages by State

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