Air is Not Fair in Strata

Many residential stratas don’t have it at all. For those that do, common air conditioning systems servicing individual apartments are likely the largest source of energy waste within the building.

On a recent site visit to a premium twin tower development in Sydney’s north, we came across more than one opportunity when it comes to air conditioning.
 
This building had one of those air conditioning systems with big units on the roof, which are connected to individual units built into the walls of each apartment, keeping residents cool during summer. As soon as one person in the block turns on the system in their apartment, the whole kit and caboodle on the roof spins up at their beck and call.

​Imagine two cooling towers on one block…..those are the things that have water circulating around the building to cool the apartments down, coming back hot and then trickling their way through a roof-top system to get cooled down again before starting the merry journey all over. A bit like a hamster wheel, without the entertainment factor.
 
Moving over to the second tower, there was a dry cooler system operating there, instead of a water cooled tower. Now what could possibly go wrong in a setup like this.
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Maybe a faulty call signal from one of the internal apartment systems, could be triggering the condenser water pump to start working on a chilly 14 degrees morning? A temperature controller could fix this by locking out any activity at say below 16 degrees, saving energy.
 
Old school cooling towers have fixed-speed drives which are belt-driven. Modern direct drive motors are more efficient than belt-drives and accelerate and decelerate like a Tesla. Next opportunity was to replace one of the cooling tower fans with a variable speed drive (VSD).
 
Now let’s have a look at the dry cooler. Yes, that is base corrosion. Also, that corrosion has spread up the heat exchanger (the heat exchanger is the thing that looks like metallic bubble wrap). Corrosion on a heat exchanger could be reducing performance by 12%-14%. Extracting all the coils and removing the corrosion will protect and extend the life of the coils. You could go one step further and improve the thermal conductivity of the coils, using a protective coating such as Nanosure.
 
Want to go even further? What about “soft start” water pump motors being installed to reduce those capacity charge bill shocks?
 
We all know how hard it is to get everyone in their apartment to open their door for the annual fire check. However, some stratas with these types of air conditioning systems haven’t had the local systems installed in each apartment serviced since the building was first constructed. This can be 20 years between services.
 
Maybe it’s time for an additive to be  injected into the refrigerant in each apartment’s local unit. Otherwise, individual apartment owners might start installing their privately owned split systems on the balcony, literally driving the carbon emissions of the building through the roof.
 
Just when you thought it couldn’t get any worse, a corporate datacentre in the commercial suites on the ground floor was found to be putting more than its fair share of load on the cooling tower and being subsidized by all apartment owners. To put it short, in these type of strata buildings more effort needs to be put into “keeping the air fair”.

Brent Clark
CEO, Wattblock

Strata managers can now register buildings in the City of Sydney and in Melbourne for a fully funded electric vehicle recharge assessment. Registrations for Brisbane have closed. However, if you're interested in learning more contact Scott Witheridge on (02) 9977 1801. Read more about the program here.
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