Cooling without air conditioning

Luke Murphy
24th October 2019 in Case Studies
A study by Graz University of Technology has confirmed what everyone who has experienced Loxone first hand has known for a while now – you can keep a room significantly cooler (up to 9°C to be exact) simply by using a combination of automated blind and ventilation control, without the need for any air conditioning whatsoever. 

During the summer months when the sun is blazing down us brits are reminded all too brutally that the heat isn’t always so desirable. Our homes & offices become saunas rendering sleeping, concentrating and many other things borderline impossible. We’re left longing for air conditioning because we believe that’s the only solution to our problems. However, a recent study carried out by the Laboratory for Building Physics at Graz University of Technology has come to a different conclusion. “With a combination of intelligent blind and ventilation control, it is possible to reduce room temperature by up to 9°C without actively cooling (aka air conditioning).” – Selina Vavrik-Kirchsteiger, Head of the Study and Expert in Research and Development.

So just lower the blinds and we’re all sorted? Well not quite. The study also states that “the control of blinds (or any other form of shading) by an intelligent system shows clear advantages compared to purely manual control.”

The scientists found that although just leaving the blinds lowered did help – intelligently automated shading did far more to lower the temperature. The reason for that is because permanently closed blinds (or shutters) prevent heat dissipation and also hinders the ventilation process.

To achieve optimum cooling “integration of ventilation into the system proved to be very advantageous” – significantly affecting the temperature of a room through the night by taking advantage of the lower outside temperatures.

This video shows how the temperatures in a home with intelligent blind and ventilation control compared to a conventional home on a hot summer’s day: 

© WOUNDWO

TIP:
Only use
ventilation at
the right times.

TIP: Only use ventilation at the right times

“The problem comes if ventilation is used when the outside temperature is very high. Although it brings short-term advantages such as providing better air quality – it eventually warms the room in the long-term. Ventilation should, preferably, only be used in the evening and at night when the temperatures are lower. A fan should rather be used during the day”

Even without a ventilation system, Loxone can still help you ventilate your home by letting you know when you should open the windows and when you should close them. 

Up to 80% of solar gains can be stopped 

A well-planned, well-tuned and well-executed shading system can not only increase the comfort of a room but also reduce energy consumption.” Up to 80% of the solar energy radiated on a hot day can be blocked with automated blind control.

 

“With the awareness of climate change rising, it safe to assume that the shading of houses, offices & buildings in general will become more prominent. You can achieve a lot with an automated shading system however even greater results can be seen if the system ties in other components such as heating, ventilation and lighting.”

 

Automated blinds – also useful in spring, autumn & winter 

The study doesn’t only look at the conditions present in summer. The scientists also analysed the conditions in winter, autumn and spring.

The results? Even then, automated blind control had a positive effect on room temperature.

In winter: “The knowledge that an automated shading system can positively contribute to comfort and energy efficiency in winter in unfortunately not widespread enough.”

When it becomes cooler outside the blinds work with a different goal in mind, on the one hand, they act as a sort of ‘heat cover’ for the room – serving as an additional layer of insulation between the warm room and the cold outdoors. Whilst, on the other hand, raising when there is an opportunity to heat a room using natural energy from the sun. 

Autumn/Spring: Depending on the weather conditions the shading system should, essentially, prevent rooms from becoming too hot during the day and too cold at night. “During this period, a good system can go a long way in reducing energy consumption whilst also increasing the comfort levels of a room.” 

9°C kühleres Zuhause beim Vergleich automatischer Beschattung gegenüber manueller Beschattung

Results of the study 

Based on a comparison with a conventional home during the month of August:

Automated blinds
with no ventilation

Automated blinds (optimised for maximum room brightness)
+ automated ventilation

Automated blinds (optimised for maximum cooling)
+ automated ventilation

During the day, when someone is in a room, completely closed blinds are obviously undesirable. When we talk about comfort, that covers far more than just the temperature. Optimising the amount of daylight in a room is also important for well-being. “The lighting conditions in a room must be taken into account when someone is present. People should not feel as if they are about to explore caves in the middle of the day.”

– Special Tip –

Intelligent blind control with Loxone


Learn more about blind control with Loxone. Thanks to the nature of our system and our wide range of extensions our solution is extremely flexible – making it perfectly suited for smart homes, commercial premises and custom applications.