How apartments can reduce their energy and water footprint

Whether your whole strata committee is on board or not, there are still plenty of things apartment dwellers can do to reduce energy and water bills and carbon emissions, according to Ethan Burns, managing director of Sustainability Now.

Burns is one of the energy efficiency and sustainability consultants who will be offering free advice at the Alternative Technology Association’s Speed Date a Sustainability Expert event in Ku-Ring-Gai on 17 October.

Organised in conjunction with Ku-Ring-Gai Council, the event will also have leading eco-architects Caroline Pidcock and Dick Clarke, as well as experts in solar, green roofs, water sensitive urban design, permaculture, and council planning and bushfire staff.

Burns’ consultancy has developed a specialist area in the apartment sector, carrying out about 230 projects for strata buildings across Greater Sydney over the past five years, including more than 100 level 2 energy audits for whole buildings and a range of retrofit and upgrade projects.

Burns says the level 2 audit is a holistic one that looks at all the opportunities a strata building has for reducing energy use.

Common area lighting the low-hanging fruit

One of the key “low hanging fruit” strata can achieve, he says, is upgrading car park and fire stair lighting to LEDs with occupancy sensors.

Fire stairs are generally rarely used, but traditionally have halogen or fluorescent lighting that runs 24/7. A retrofit of LEDs will give an immediate 50 to 60 per cent saving on energy use, Burns says. And by retrofitting an LED sensor light with occupancy sensors in the batten, where the lights are dimmed unless someone is actually using the fire stairs, the savings can be 90 per cent or more.

With car park lighting, a similar principle applies, but with a lower saving due to the level of activity in car parks. There are also “more decorative” versions of LEDs now on the market that can be used for common areas, he says.

But changing energy prices are altering the business case for the larger strata bodies, he says.

“The ROI is not as good as it used to be, which means the business case is not as great,” Burns says.

Larger strata buildings that are on an industrial or commercial tariff have seen prices drop by 20 to 30 per cent recently, he says.

“As a rough rule of thumb, anything over 50 apartments is on a commercial/industrial tariff.”

Burns says the price drop has come about due to a reduction in network prices, with the Australian Energy Regulator ruling there is to be no more “gold plating” of the network, a cost that had been adding to customer charges.

“But still, if you’ve got a building with double four-foot fluorescents running 24/7, the payback can be as low as two-and-a-half to three years, and that’s without factoring maintenance into the equation,” he says.

And for strata buildings with 30-40 apartments, which are generally on the small to medium enterprise commercial tariff, the business case remains sound, as prices for these customers have not gone backwards.

Ventilation an easy win

Car park ventilation systems are another easy win. Burns says that according to Australian standard AS1668.2 for car park ventilation systems, the fans need to operate 24/7 unless monitors have been installed for air quality – specifically carbon monoxide concentrations.

“But in residential strata it is uncommon to find them running compliantly,” Burns says. “Often they are on timers for the perceived high traffic periods. But that is not a compliant approach, and it is also not really a risk-based approach.

“Some of those fans are also huge – 75 kilowatts.”

The solution his consultancy has implemented for many buildings is installing carbon monoxide sensors around the car park, and also for some projects, coupling the fans to variable speed drives that mean the fans will only operate at the speed required to mitigate the detected levels of CO.

While it is not common across residential strata, he says some of the larger buildings do have common airconditioning systems and common supply of chilled water to the apartments. Where they do, efficiency gains can be made by swapping single speed fans and pumps for VSDs and pressure transducers.

Another gain large buildings can make if they are on the commercial/industrial tariff is installing power factor correctors.

Pool pumps are another potential saver, he says. Many of the newer models already have VSDs built in, but there are “smarter ways” to do things, like taking advantage of off-peak billing periods for higher speed filtering.

On water

In terms of saving water in apartment buildings, there is most likely only one meter at the front gate for the entire building.

“The finest data you can get is your quarterly utility bill,” Burns says.

“The best way to make a saving for the entire building is to fit a real-time data logger (temporary or permanent) to this meter and monitor overnight base-flows to detect leaks. The base-flow should drop to almost zero between say, 1am-3am. If not, it’s likely there are leaks.

He says that unless there are obvious, major leaks, fixing things like dripping taps and toilet cisterns and installing WELS rated shower heads and flow regulators offered the best ROI.

New avenues to help strata bodies

Burns’ consultancy has been looking at new avenues for assisting strata bodies, including putting together a generic lighting tender.

“A big lighting project is quite expensive; it’s not a cheap easy fix. You are looking at between $50,000 and $100,000,” he says.

“You want to do your homework and get a few quotes”.

The tender he is developing adds value, he says, by ensuring suppliers are quoting for exactly the same things, and using the same set of assumptions for the calculations of ROI.

“I standardise all the input parameters so you can compare apples with apples. And then on behalf of the building I put together a tender report so they can make sense of the information.”

Burns says there is “a lot of buzz around solar” but really poor uptake to date in the strata sector. He is currently completing a feasibility study for one body, and recently project-managed a 17.5kW installation for a strata apartment in Kensington.

One of the barriers to greater uptake, he says, is that for the buildings on the commercial-industrial tariff, the payback is “too long” at about 15 years, because their current electricity is “too cheap”.

“Smaller buildings on the SME tariff have an opportunity, with about a five year payback if the electricity [generated by solar] is used for common areas,” Burns says.

“They also have a better opportunity if the individual residential apartments want to use it, if the distance between the apartment meters and the roof is not too large.”

However, as things currently stand, if residents are not home during the day when the PV system is generating power, and the overall energy efficiency is good, Burns says it will probably only be the fridge using any power and the rest will be exported to the grid.

This, he says, is a waste of capital.

But with the advent of microinverters, there are more opportunities for smaller systems, and ensuring the solar is right-sized to meet minimum daytime demand for common areas and potentially apartments is a sensible strategy to avoid “overkill”.

Sustainability suggestions that don’t need approval

For those living in apartments wondering what they can do to reduce their individual carbon, energy and water footprint, Burns suggests a range of simple measures that don’t require body corporate approval:

• LED lighting retrofits – these are still reasonably expensive, but if you replace all the halogen downlights with LEDs it will pay for itself in future lamp replacement costs you avoid.
• Always buy the most efficient appliance you can afford and consult www.energyrating.com.au to make sure you are buying “the best in its class”. The cost will pay for itself over the life of the appliance in terms of reduced running costs.
• You may not have a lot of control over hot water if you are on a common system, but installing flow regulators in kitchens or hand basins will save on the overall building’s bill – and therefore strata levies – where there is common metering. And for apartments built after November 2014 where individual metering is now standard in Sydney, there is even more incentive to save water.
• Some strata buildings allow the installation of split system airconditioning for individual apartments – this is more energy-efficient than using electric heating elements.
• Unfortunately, many apartments don’t have the benefit of cross-ventilation, but it is still possible to implement a degree of passive ventilation through strategic opening and closing of windows and use of ceiling fans.
• The strata body may not permit the installation of external shading, and Burns says that “once the sun’s hit the window, you’ve lost the battle… but a good set of thick curtains will provide some insulation both from summer heat coming in, and to manage loss of heat in winter”.
• Having a few plants or some other foliage on your balcony or terrace might also add a cooling element.
• Buy a certified 100 per cent Green Power product. This is available for both electricity and gas. Electricity comes from a renewable resource and the gas is a carbon offset.