Have you ever walked into a cinema or shopping centre on a blazing hot day and, upon feeling that blast of chilly air, wondered why you didn’t bring your ski jacket along? It’s known as thermal shock and it’s a “preposterous” situation that Tony Crabb, national head of research at Savills Australia, wants to end with the “19-25 concept”.

Mr Crabb, who presented “We can live in a 19-25 degree world!” at TEDxQueenstown in New Zealand in April, says governments and companies could save millions of dollars and drastically reduce their carbon footprint with a simple adjustment to the way they use airconditioning.

HVAC systems in offices, shopping centres and other public spaces are generally fixed at what is considered to be an optimal 22 degrees Celsius. This is based on an arbitrary standard that takes no account of outside temperatures and comfort levels.

“Why?” Mr Crabb asks during his TEDx talk. “Because it is the thermal comfort level of a 44-year-old man, which was determined by the Americans in the 1950s. I kid you not.”

Instead, Crabb advocates heating and cooling all our buildings to a 19-25°C range.

“We don’t heat them past 19 degrees and we don’t cool them below 25 degrees,” he says.

“If the temperature outside is 35 degrees, 25 degrees is quite comfortable. Likewise, if the temperature outside is nine degrees, 19 degrees – that’s just nice. The work that the system has to do to get from 19 to 22 or 25 down to 22 is a lot.

“The crazy thing is the manufacturers of the systems recommend that they be run at a range of 19-25 degrees. And yet we run them at 22. We thrash them.”

Staggering savings that won’t cost a cent

In Australia some 40 per cent of our energy is consumed in the built environment and a large amount of that energy is used in heating and cooling.

“There is an easy way to cut that energy use,” Crabb says.

Back in 2008 the United Nations, as a publicity stunt at its New York headquarters, adopted a temperature range of 19-25 degrees. They estimated the savings at $US100,000.

“In Australia, if we did that in the office buildings and shopping centres we’d save $100 million in a year and slash carbon emissions by 300,000 tonnes guaranteed – and it wouldn’t cost a cent,” Crabb says.

“Now let’s run that out through all the other property in the country including residential and then run that out around the world and we are talking billions of dollars and millions of tonnes every year.”

Make it mandatory

Irrespective of the dollar savings, Crabb says it’s incumbent upon governments and industry to make the adjustment as part of their social responsibility.

“There are people who work in the industry who know better but they are told to leave it there,” Crabb says.

He believes the 19-25 concept will be difficult to regulate because current legislation is designed to deal with building and construction codes or occupational health and safety.

“There isn’t any legislation designed to tell you how to run a building,” Crabb says. “It’s not cut and dry. I wish it were – that we could write a piece of legislation that says: you cannot prescribe the temperature, or it has to be in the range of 19-25.”

However, Crabb believes a public education campaign like we saw for kerbside recycling is the way to go.

“They introduced that; everybody got it,” he says. “Everybody will get 19-25.

“And maybe we do it through the NABERS ratings and a range of other initiatives.”

New habits are needed

In the race to reduce carbon emissions, Crabb says people have become too focused on fossil fuels versus renewables and have forgotten about reducing energy use.

“Sometimes you can’t see the wood for the trees. You are too close to it; you are busy focused on alternatives rather than on modifying use,” he says. “They are all looking at solar, wind and water and sustainability; they are actually not looking at energy use and, if they are, they are not looking at it closely enough.”

Just as we look out the window (or check the weather app) and wear a jacket or carry an umbrella to adapt to the conditions, we need to we ask our buildings to adapt too.

“We say to our buildings, you are going to wear the same clothes day in and day out regardless of the temperature outside,” Crabb says. “Why wouldn’t you adopt some flexibility with regard to your air-con temperature settings?”

While an arbitrary 22 degrees is often written into leases, Crabb says ignorance, laziness and thoughtless also play a part in the situation.

“Most of it is bad habits,” he says. “We should all start living in a 19-25 world and we can all do it.”

The Savills Green Tenancy Guide provides a range of solutions for occupiers of space who wish to cut carbon emissions including:

  • Turning off lights, computers and photocopiers at night
  • Setting default double-sided printing
  • Using rainwater tanks to flush toilets
  • Switching to 100 per cent renewable energy

See also The Fifth Estate’s Tenants and Landlords Guide to Happiness.