This Case Study and Q&As are about maintenance requirements for a mechanical ventilation fan or ventilation system installed in apartment buildings, including stopping low frequency fan noise.
Table of Contents:
- QUESTION: Does the mechanical ventilation fan require any sort of regulatory inspections to ensure it is in good working order and complies with clean air etc?
- QUESTION: An air conditioning plant sits on the roof directly above our apartment and causes us concern from a low frequency fan noise. How can we stop the noise?
- ARTICLE: Apartment Block Residents Stressed by Fan Noise [Case Study]
Question: Does the mechanical ventilation fan require any sort of regulatory inspections to ensure it is in good working order and complies with clean air etc?
Our building has three levels. There are duct panels that carry the mechanical ventilation system between the different levels and eventually to the outside air on top of the roof.
Does the mechanical ventilation fan require any sort of regulatory inspections to ensure it is in good working order and complies with clean air etc? Our system has been installed for 11 years or more and has never been inspected.
- There are items like air filters (for supply air) that need regular replacement
- Does the system do what it should in Fire Mode (typically shut down in a fire alarm)
- Bearings and belts on the fans and fan motors, lubrication, tightening, noise, full load current of the motor, contactors, Fuses, etc….
- Fan motor control from the switchboard, does it work as it should, are the terminals tight (loose terminals are a fire hazard as they can arc), is the control of the fan via a time clock, is the time clock correctly set. Does it work?
- Therma graphic scan of the mechanical services switchboard the Fan is served by ( this is also a typical requirement of the insurance company)
- Clean the duct every few years (a dirty duct can be a fire hazard as well as an environmental/health concern)
- There could be some energy management opportunities here, is the fan motor on a variable speed drive? Is it Direct on Line (DOL)
- Are there Fire Dampers in the system, these need to be checked regularly (%20 every year)
- Flexible joints need checking, is the system leaking air
- Secure mounting, the systems vibrate and can work them selves or part there of loose and become a hazard.
- and there’s more….
This post appears in Strata News #471.
Question: An air conditioning plant sits on the roof directly above our apartment and causes us concern from a low frequency fan noise. What can we do about the noisy exhaust fan?
We live in a 7 story Strata, completed about 12 months ago, containing 30 units and a ground floor retail/commercial area. The building is a mixed-use development with two owners corporations i.e one lot has 30 residential lots and the other comprises the retail/commercial.
The retail/commercial owners corporation has an air conditioning and refrigeration plant located on the roof of the residential lots. This plant is directly above our unit. The plant equipment is causing us some concern from a Low Frequency fan noise inside our apartment and we are looking to the Owners Corporation to take action to rectify it.
The Strata Committee has advised us that as our apartment is the only unit in the complex that is affected by the fan noise. Because of this, it is up to us to take our own action against the owner and or the tenant of the retail/commercial lot. To this end we have on numerous occasions raised the matter with the owners of the retail/commercial Lot with no action forthcoming.
At our expense, we have engaged an acoustics engineer to provide evidence of the noise problem and intend to again approach the Strata Committee in an attempt to get some action. What can we do about the noisy exhaust fan?
- Does the Strata Committee/Owners Corporation has any obligation to take action since the issue appears to only affect one unit.
- If it is up to the Strata Committee to take action, who would pay the costs of any action that may be required to enforce rectification of the problem?
- Are we entitled to claim a refund of costs we have incurred to investigate and prove that the issue exists?
- If it is an Owners Corporation responsibility is it possible to get a ruling from an authority in order for the Strata Committee to realise it has an obligation to act?
Answer: You have the option to pursue the nuisance provision.
You have the option to pursue Section 153, the nuisance provision, which an individual can do. You don’t need the Owners Corporation to do this for you.
Section 153 is a wide ranging provision covering a multitude of sins. Eg that an Air Conditioner is only used during certain times, whether on common property or lot property.
Head to Fair Trading (and hopefully get a consent order at mediation) or NCAT, if you can’t reach an agreement. Once you have the order, if the other party breaches, like with any NCAT order, you can pursue enforcement via NCAT. NCAT can issue fines and penalties etc to suit Eg the removal of the air conditioner plant.
This is likely to be far more effective than a breach of bylaw order/penalty but as always it is about proving your case, as you would in any court of law, with independent evidence.
This post appears in Strata News #284.
NAT: Apartment Block Residents Stressed by Fan Noise [Case Study]
Recently, Trackie was asked to inspect a multi storey apartment block where the ventilation fans on the roof of the building were creating quite a racket! So much so that the residents of this building had taken drastic measures such as climbing onto the roof to turn the fans off. They were clearly frustrated as this is a big no, no.
As it turns out, the fans at this property were noisy, worn out and were at the end of their service life (15 years old). Coupled with high energy consumption, these fans needed to go.
One solution would be to replace the fans like for like, however, this would reduce the noise but the energy costs would remain quite high.
Instead, there is an energy efficient solution that is whisper quiet and comes in the form of an Electronic Commutated (EC) fan. By replacing these fans with EC fans, energy consumption will be slashed because they use less than half the energy of the traditional fans!
How is this possible you ask? Well, it’s because fan speeds can be reduced by 75% which equates to fans being nice and quiet while at the same time, maintaining accurate air flows.
What’s involved in the rectification process?
Step 1: Air Flow Pre Reads
We needed to enter each apartment to carry out air flow pre reads. This process reveals the current air flow position within each apartment. Some apartments are likely to have minimal air flow while others have high levels of air flow.
Step 2: Analysis of Mechanical Drawings
Mechanical drawings are analysed to identify:
- which fans serve which apartments,
- how many inlets there are and finally,
- the required air flow for each inlet.
These calculations provide figures for total air flow requirements in the building. This coupled with duct length and static pressure provides the information required to design the fans for the specific building. It’s usually the case that fans are slightly oversized so that they can be slowed down for extra efficiency.
Step 3: Balance Air Flows
When the fans have been installed, each apartment will need to be accessed a second time to balance the air flows as per the calculations. Once complete, the residents will enjoy adequate ventilation/air flow, peace and quiet and finally, reduced energy consumption.
In summary, the fan rectification process involves:
- taking air flow pre reads,
- engineering energy efficient EC fans,
- installation of new EC fans and finally,
- balancing the air flows so each apartment receives the air flow, as well as the peace and quiet they deserve.
So next time you see someone climbing onto the roof of an apartment building to turn off the fans, maybe it’s a sign that it’s time to get them checked out!
This post appears in Strata News #252.
Have a question about air flow in apartments or something to add to the article? Leave a comment below.
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