Research tell us perfect truck cab temp

Sweet spot seen as between 19-25 degrees and 20-60 per cent humidity

Research tell us perfect truck cab temp
Researchers hope their study will influence truck cabin temperature control


Research with Australian input on optimum truck cabin temperature and humidity levels is said could influence the future design of automotive air-conditioning systems.

An international research team involving Monash University, Zhejiang University in China and the University of Pennsylvania in the US believes "truck drivers globally could soon have access to state-of-the-art temperature control in their cabins that reduces windscreen condensation and improves comfort".

The researchers spent two years investigating the air-inlet mode, temperature, relative humidity and flow speed of ventilation of air conditioners in truck cabins, and how this impacts dewing and driver comfort.

The optimal zone – where the combined requirements of occupant comfort, energy efficiency and safety were met – was when the relative humidity was within the range of 20-60 per cent and the temperature was between 19-25 degrees Celsius.

The researchers collaborated with manufacturers in Australia and China on thermo-fluid problems, such as vehicle aerodynamics, drag reduction, and thermo-fluid flows in engines.

They simulated 33 different working conditions of air conditioners – including temperatures, humidity and flow velocities – to improve cabin defogging and maximise driver comfort in a retrofitted truck cabin.

How the Advanced Safe Truck Concept project studied driver behavior, here

"The other interesting finding is that the optimised settings can effectively and efficiently control the flow velocity and temperature distributions of the window surfaces and inner cabin space," Monash University department of mechanical and aerospace engineering research fellow Dr Jisheng Zhao says.

"These findings should provide us with a basic design guideline for the air conditioning system in trucks when considering the combined requirements.

"The airflow velocity and temperature distributions should also help locate comfortable positions in the cabin."

The research notes the problem of vehicle window dewing not only affects occupant comfort, but interferes with the driver’s sight and potentially threatens the safety of driving as well as electronic equipment in the vehicle.

It adds vapor condensing is caused by the differences in temperature and relative humidity (moisture) in the air and can be resolved by adjusting the inside temperature to avoid the dewing point and reducing the relative humidity through the ventilation system.  

The highest anti-dewing efficiency was achieved when the air conditioning airflow was set to speed above 0.6 metres per second, a relative humidity of 20 per cent and temperature above 46.85 Celsius within 200 seconds.

However, cabin temperatures reaching nearly 50°C in order to reach maximum defogging capacity is unfeasible.

Results showed that reducing humidity could not only effectively control condensation, but also optimise the distribution of the internal airflow and increase the heating effect.

"On the other hand, low cabin pressure affects the occupants’ thermal comfort, whereas high temperatures will increase the content of water vapour in the cabin, thereby worsening the problem of condensation," Zhejiang University professor Yuqi Huang says.

Zhao says the findings were significant, especially for vehicle batteries, which could see losses of up to 50 per cent of the total driving distance due to energy consumption of air conditioners.

"Trucks play an important role in our freight transport system, carrying more than 70 per cent of the freight across land.

"The need for energy reductions and environmental compatibility of truck design, by improving aerodynamic performance for example, is now a worldwide priority." 

The study is available here.

You can also follow our updates by liking us on Facebook


Trucks For Hire | Forklifts For Hire | Cranes For Hire | Generators For Hire | Transportable Buildings For Hire