Blowing Hot and Cold: HVAC 101, seminar for the Melbourne 1200 Buildings Program

14 May 2014 — According to Bryon Price, strategic development director with A.G. Coombs – heating, ventilation and airconditioning systems – or HVAC, are generally quite well built and surprisingly resilient.

For quite a while you can get away with neglecting them – minimum service, maybe some “drive by” inspections, and hardly anyone will notice. The temperature will remain dutifully steady at 21 degrees or so, and it will be ages before the occupants complain that the air is getting stuffer.

But sooner or later, the fruits of your neglect will come back to bite you. Components may fail and you could be shaving five to 10 years off the life of your kit, Price said.

And that can hurt. A chiller, he said,  could set you back $120,000 to $350,000. A pump alone could be $2500 to $15,000. In fact, a rule of thumb for replacement costs is about $450 a square metre for an average building to $700 a sq m for high end equipment.

Bryon Price

Price was speaking at seminar last week organised by the City of Melbourne’s 1200 Buildings program, and yes, what he said was intended for maximum effect.

Sitting before him were some of the elusive owners and managers of B grade, or “mid-tier”, building owners that the City has been trying to target and motivate to retrofit their buildings for greater energy efficiency since the program was launched in 2010.

It’s a significant and important ownership group. Private owners control 47 per cent of Melbourne’s net lettable commercial space (compared with about 42 per cent NLA controlled by corporate owners). This translates to a potentially big whack of carbon emissions from the CBD that is not being tackled.

But it’s been tough going. This sector of the market is notoriously difficult to connect with, let alone engage. As of  mid-2013 the program had only 57 buildings signed up, with just seven buildings signing up in the preceding two years. But organisers say this is not an accurate measure of the program’s success. Many owners are intensely private and reluctant to sign a commitment agreement, they say. A better measure of engagement is the biennial retrofit survey that shows retrofit engagement is growing well (see graphic).

Among the barriers to greater retrofit activity is a general lack of understanding about the technical issues associated with commercial buildings.

Michele Leembruggen, introducing the seminar

Michele Leembruggen, acting team leader for the 1200 Buildings program, told The Fifth Estate in January that the City‘s 1200 Buildings Melbourne Retrofit Survey 2013 revealed a general lack of awareness among mid tier property owners regarding their buildings’ energy performance.

That’s not wilful ignorance. A big proportion of the cohort – about 70 per cent – intended to keep their buildings for 10 years or so. This means  assets were not likely to be soon impacted by the Commercial Building Disclosure legislation, which requires all offices of 2000 sq m or more to carry a NABERS Energy assessment, a tenancy lighting assessment and general efficiency guidance when they are sold or leased.

Without the CBD program forcing the issue it’s tough to convince these owners to take action to improve their buildings’ energy performance.

Retrofit activity in Melbourne

“Private owners often do not have the corporate structures and resources to research, facilitate and track building performance,” Leembruggen said in the January article.

“They do not proactively manage building performance and want to see cash flowing into their businesses, not out.”

That leaves old fashioned information and education to do the work of engagement, which is where the seminar series comes in.

Blowing Hot and Cold – HVAC101

So the healthy turn-out last Tuesday at the Melbourne Town Hall of nearly 50 people was a great result. It was double the levels of last year’s seminar.

And, better still, it seemed everyone was paying acute attention.

Price did not disappoint.

His first of two seminars, “Blowing Hot and Cold – HVAC101”, stepped though the fundamentals of HVAC from a technical point of view, moving quickly to the critical role HVAC  has in overall building performance and tenant satisfaction.

“Comfortable, productive, sustainable work environments and HVAC are central to tenant services, health and safety,” Price said.

In fact, as many observers have told The Fifth Estate, indoor air quality has emerged as a strong determinant of office productivity and the race is on the measure and map the impacts.

It’s also key to tenant satisfaction. Aircon that’s too cold, too hot or too stuffy can be one of the biggest bugbears of unhappy tenants – sometimes a deal breaker, therefore  a threat to the rental stream.

Poorly performing HVAC can also be a direct threat to the bottom line. The better the kit, the smoother and cheaper the running costs. Potentially. You still need to monitor, tune and maintain the kit in prime working order if you want to prolong its life, Price said. “Just like a car.”

He also touched on regulations. HVAC is key to air quality with myriad associated health issues and threats such as Legionella, as well as to fire safety.

“Some would argue this is the most regulated industry in the country,” Price said.

Simple but not

While the fundamental design of HVAC systems are simple – essentially an an “air box” through which hot or cool water passes in pipes to change the temperature of the air – a building’s system can quickly spiral into much greater complexity.

For instance, a typical single floor in a major office building might have five “air boxes” or zones to deal with – one in the centre of the floor that is never impacted by the heat loads of sunlight and another in each of the  major orientations of east, west, north and south.

The HVAC needs to balance the competing influence of the zone’s location with the changing heat load for the time of day, the number of people on each floor and the uses, Price said. Next multiply the number of zones on each floor by the number of floors in the building and suddenly you get a picture of why the facilities manager sometimes looks stressed.

Adding to complications is the building management system – the “brains and nervous system” of the building that regulates the HVAC.

A key message from Price was not to let the technicalities get in the way of understanding. Using the car analogy again, to get the best out of a machine, it helps to understand how it works and what its potential is. Also how to keep it running to the best of its ability.

Price urged owners and managers to “get to know their maintenance contractors”. Technical people are happy to talk over the technicalities of their job, he assured.

Change and the importance of planning

A good relationship with the FM can be of great help when it comes to managing a failure in the system or a complete upgrade.

Change can be very challenging, Price said.

Having a well thought out plan for contingencies can come in handy if a component fails, say, on a weekend, and you need to have everything in good working order by Monday. Do you panic and replace like with like? Or do you refer to the management plan and seek out the piece of kit that shows a 15 per cent energy efficiency improvement for a similar price?

Retrofits that involve changing the whole HVAC can be worse, Price says.

“If you need to undertake a retrofit how do you do that in an occupied building, and keep it working while you change the system a floor at a time?” he asks.

Energy costs: $70,000 difference in bills between 1.5 Star and 4.5 Star NABERS Energy. That’s $70,000 available for energy retrofits

And the cost?

One of the most powerful moments in Price’s presentation was the chart showing the difference in cost of energy for a range of NABERS Energy ratings.

Between 1.5 star NABERS Energy and 4.5 stars, the difference in energy bills are typically a whopping $70,000 a year for a building of 5000 sq m. So, that’s about $70,000 a year you can spend on upgrading your system and still be ahead, Price pointed out.

All of this starts to change from interesting to acutely interesting when you realise that the price of energy is heading in only one direction, and that’s up.

The rising cost of gas prices has also put a massive dampener on gas fired trigeneration and cogeneration power plants, Price said.

The reason is that “we’re in the process of building two to three gas trains to sell gas overseas so we will have to start paying international parity prices for gas”.

This is also putting pressure on electricity prices.

One option is to shift the time of use load so that you buy most of your energy at 2am when it’s cheapest instead of 2pm when costs are at their peak, and find an energy storage solution.

You can also bargain to negotiate cheaper deals that are available for bigger customers. In the commercial space these days, there are “cracker deals out there”, Price said.

But there’s an ironic counterpoint to that. Be warned that this doesn’t provide an inadvertent licence to be profligate with your energy consumption. It’s been known to happen.

Seminars are by invitation. For details, contact

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