Cover Story: Using heat to cool

This article first appeared in Unlisted & Unlimited, The Edge Malaysia Weekly, on February 8, 2016 - February 14, 2016.

[My father] used to bring home all kinds of gadgets when we were growing up. So, when I was home after I quit my previous full-time job, he showed me a new research paper on what he called ‘solar dingin’, and I couldn’t get the term out of my head. > Azrina

(From left) Surendran, Azrina and and Teoh with the thermosyphon solar vacuum tubes

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Teoh Siang Teik invented the multivalve thermosyphon solar vacuum tubes for aid groups who wanted an efficient solar heater that could work without electricity in the highlands of Nepal. Azrina Yusof needed a super-efficient heat exchanger to power her air-conditioning units so that they could run without guzzling electricity. Their partnership was a match made in heaven.


The major gripe of anyone who uses air conditioning is the exorbitant cost of electricity. It is estimated that in a typical home, air conditioning consumes at least 60% of the total electricity cost. Worse still, as we turn on the air conditioner to cool ourselves, we are burning fossil fuel, which makes the Earth hotter, so we have to cool ourselves even more — a vicious cycle, to say the least.

SonneAire Solar Air Conditioning System may have a solution with its revolutionary “solar dingin” technology, which not only promises to cut one’s electricity bill by more than half but also extends the lifespan of the air conditioning unit and supplies hot water [for showers] at the same time.

While air conditioning has come a long way since Willis Carrier invented the modern air conditioner in 1902 using ice and fans, the cost and energy consumed by air conditioning units have been far from satisfactory for those bent on reducing their carbon footprint, says Teknologi Inovasi Solar Sdn Bhd founder Azrina Yusof.

Like other power-saving air conditioning units in the market, SonneAire’s product is a hybrid model. But the company, which was founded in 2012, uses solar energy captured and retained using “thermosyphon solar vacuum tubes” to heat the cooling agents, thereby slashing the energy consumed by the compressor by at least half. 

The multivalve solar vacuum tube is the brainchild of architect turned solar technology enthusiast Teoh Siang Teik. The patent for the technology is held by Teoh’s company, Micro Solar System. 

“One of the key things is to cut costs. Air conditioning is generally all about temperatures and pressures,” says Azrina, a software engineer by training. Existing energy-efficient technology has grown by leaps and bounds, but it still comes with a hefty price tag. 

During the developmental stage of the solar-powered air conditioning unit, Azrina approached a number of photovoltaic cell manufacturers to get an estimated cost of a one horsepower air conditioning unit. 

“They told me that they can’t make anything for any less than RM50,000 each. The price was not at all attractive to turn my idea into something workable, so I needed to find another way,” she says.

Azrina was also steadfast that her product had to be environmentally friendly and sustainable. “Air conditioning consumes a trillion kilowatts of power a year and is expected to rise tenfold in the next three decades, with Asia surpassing the US in consumption,” she points out.

It was then that she was introduced to Teoh, whose thermosyphon solar vacuum tubes were being used to supply solar-heated water. Thermosyphon is a process used to exchange heat from liquids without a pump.

SonneAire’s air conditioning units use water-based chillers, says Azrina. “In the market currently, manufacturers still add chemicals. SonneAire uses the most environmentally friendly HFC gas, R407C. This is completely natural and is the easiest way to stay cool.” The vacuum tubes used in the invention are made of silicate glass.

“Our product uses a technology similar to that of air conditioning. It taps into the sun’s heat to create a second stage compression cycle that helps to reduce the electricity consumption by the compressor. Conventionally, the highest energy consumption in an air conditioner is used by the compressor to heat up and compress the air conditioning gas,” she explains. 

SonneAire is able to use the excess heat from solar stored for the air conditioner, which comes with an in-built ioniser, to run a free hot water system. “While it is a hybrid technology, it still saves us from having to incur high electricity costs. This compares with using photovoltaic cells to generate electricity, for which you pay an upfront cost of RM50,000,” says Azrina.

“We needed an efficient heat exchanger. Teoh’s micro solar is a very efficient heat exchanger. That’s why we decided to go into this business together.”



Teoh invented the multivalve thermosyphon solar vacuum tubes in 1981 for a project commissioned by the United Nations Development Programme (UNDP) and the US Agency for International Development (USAID) when he was working as an architect in Nepal. The international aid groups wanted an efficient solar heater that could work without electricity in the highlands of Nepal, particularly in winter.

“As the architecture director of one of the largest companies in Nepal at the time, and not being well-versed with solar thermal development at that time, I signed on the dotted line thinking that plenty of solar heaters could work in the winter,” recalls Teoh.

“It was only after committing to it that I found out that no one had made a solar heater that could work on cloudy days and in winter without electricity. I was clearly in trouble because we were on a project time scale and within six months, we had to come out with this solar heater we had promised to deliver.” 

Strapped for cash and time, Teoh designed his own solar-powered water heater with coaxial multiple vacuum tubes using infrared tubular technology, for which he later gained much international recognition in the solar engineering field.

Azrina’s other partner is Surendran Veera, a mechanical engineer and former colleague who now runs an air conditioning business. He acts as a consultant and is involved in designing as well as fitting the final product. 

“It is not very innovative in terms of design. It doesn’t look like anything out of this world. But it is meant to make the world a better place,” he says.

Azrina says she got the idea to design earth-friendly air conditioning units during a conversation with her father, a physicist at Universiti Kebangsaan Malaysia, who was involved in solar energy research. “He used to bring home all kinds of gadgets when we were growing up. So, when I was home after I quit my previous full-time job, he showed me a new research paper on what he called ‘solar dingin’, and I couldn’t get the term out of my head.

“The very next month, I set up this company and registered Teknologi Inovasi Solar. But for six months after that, I didn’t do anything but read. My father gave me a 500-page book on solar technology and another on the Green Building Index (GBI).”



However, the venture has not had a big breakthrough because people in general associate renewable energy with high costs. “They always think it won't take off,” says Azrina.

This was also the reason the product, which was initially called solar dingin was rebranded as SonneAire, to appear more desirable to locals. After much persuasion, the company got its big break when Northport (M) Bhd — one of the largest private port operators in the region — decided to fit several solar air conditioning units in the its warehouses in Port Klang. This was in June 2013.

“It took us another six months to convince Northport, but they eventually agreed as they were on a drive to save electricity. They had been spending so much money on energy that they needed to find other ways to ensure their routine operations were not disrupted,” says Azrina.

“Where Northport is, the situation is quite hazardous. It is coastal and there is a palm oil mill just beside it. With the dust particles from the mill and salty humidity from the sea, the air conditioning units were breaking down every three months.

“So Northport really stress-tested our product as they placed the air conditioning unit inside a heat gain room, which is similar to an oven, and had it running round the clock … not to mention that its factory is near the sea, which is very corrosive.”

The result? The SonneAire units received a 90% score and they inked the agreement. 

“We got a free testing ground and the actual data on how the unit behaved when installed in a harsh environment, as well as how it behaved in the rainy season in such conditions,” says Azrina. 

Teoh says Microsolar’s circular glass tubes absorb infrared rays, which are present even when the sky is overcast. “Photovoltaic cells are not so good at absorbing solar energy on overcast days. Infrared rays come from all directions, but photovoltaic cells are on flat panels — the physical shape hinders absorption. The transfer of energy for thermal cells are 70% while photovoltaic cells are only developed to transfer about 20%,” he adds.

Surendran fondly recalls the installation of a solar-powered air conditioning unit in the attic of a house in Taman Overseas Union, Kuala Lumpur. “The occupants were struggling in sweltering heat despite having 14 air conditioners. The house had been built in a way that there was not much air circulation. But the temperature dropped from 47°C to 18°C after we fitted SonneAire in the attic,” he says.

“It got so cold that the house owner forgot that the water tank was in the attic and the water was freezing. We had to cut a hole in the ceiling to let the cold air flow throughout the house. So now, at any time of the day, the house has an ambient temperature because cold air sinks and the electricity bill is half of what it used to be.”

The solar energy supplied through the vacuum tubes is not affected by the quota set by the Sustainable Energy Development Authority (SEDA) as it is not connected to the grid to enable the excess energy to be supplied back to the grid. The statutory agency, set up under the Ministry of Energy, Green Technology and Water, administers and manages the implementation of the feed-in tariff mechanism mandated under the Renewable Energy Act 2011.

“We only need about 0.65kW to run the solar air conditioners. To be connected to the grid, the energy used needs to be higher,” says Surendran. 

The business got another boost when Cradle Fund Sdn Bhd, a non-profit early stage grant provider under the Ministry of Finance, pumped in RM1 million last year. “We have since installed more than 10 solar air conditioning units in various commercial sites,” says Azrina.

The SonneAire air conditioning units come in three models — wall mounted, ceiling central and ceiling exposed. Customers can opt to have just the air conditioning units or a package that comes with hot water supply. Prices start at RM10,000.

“Last year, we were endorsed by the Malaysian Green Building Confederation (MGBC) and SonneAire is the only solar powered air conditioning unit listed in Green Pages Malaysia, a resource directory for green building products and services,” says Azrina. 

“It is endorsed with up to four points for the GBI, namely for energy efficiency (one point), materials and resources (two points) and innovation (one point). This means a building that installs Sonneaire qualifies to receive a total of four GBI points. These factors are very important for property developers to get tax breaks,” she points out.

Making its presence felt is still a great hurdle for the company, says Azrina, especially in a business environment that has become a repository of patronage-seeking individuals. “We have done our part. I will be very candid here; I have the right skin [colour] and I speak the right language. But because of political patronage, none of the talented people we represent stand a chance … this is the reality of doing business in Malaysia. I could pull strings if I wanted to, but my integrity is at stake, and we are in the green business, which is fundamentally about doing the right thing.

“When I came out with the product, I wanted to make it affordable for the masses. But if I had gone through with the business of patronage, it would have increased the cost of doing business, which would have been passed on to the customer.”

She points out that political patronage seems to be a vicious cycle in Malaysia that will never end. “We are trying very hard to be innovative to ensure that anyone who uses an air conditioning unit has access to this product,” she adds. 

Teoh, however, says the lack of presence has to do with the potential disruption the product could bring to multimillion-ringgit businesses as the solar energy vacuum tubes perform 50% better than the average compressor. “With the panels doing the work, the compressor functions mostly as a circulation pump to push the air out. So, the compressor’s eight-year lifespan increases to 16 years.

“It is not good for companies whose business is solely focused on compressors. If you extend the lifespan of the compressor, they find that it is not an amiable economic proposition for the industry. The concept is about being responsible about air conditioning as it is damaging to the environment.” 

But things are looking up for the company as there have been requests to market SonneAire in Singapore and the US, says Azrina. “We are in talks with counterparts in Singapore to have our product distributed there and we sent two units to the US, where the potential distributors have been using the Micro Solar water heaters and the manifolds. They were quite intrigued with the new development and asked for a few units. 

“We are growing organically. There are companies in Australia and the US that are using a similar technology — but without the patented Micro Solar System’s multivalve vacuum tubes. 

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