“A healthy indoor climate is recognized as a basic right. People spend a large part of their time each day indoors: in homes, offices, schools, health care facilities, or other private and public buildings. The quality of the air you breathe in those buildings is an important determinant of your health and well-being. The inadequate control of indoor air quality therefore creates a considerable health burden” (The World Health Organization 2009)
Ensuring good ventilation within buildings has always been a challenge, and there are many buildings built even today that still suffer from poor ventilation. While the goal of saving energy is commendable, at times this is the overriding factor and can have a dramatic negative effect on the internal air quality.
Airtight buildings are designed to retain heat. This means the air in the building can be recycled many times which leads to a build-up of pollutants, toxins and bacteria which are then continuously breathed in and out by the occupants. Indoor air quality has a major influence on health as stated by WHO, but still the comfort and well-being of the persons inside is often overlooked. Poor air quality has been linked to a problem known as the Sick Building Syndrome which can reduce productivity in offices and impair learning in schools, and lead to the spread of viruses and airborne illnesses.
We spend an average of 90% of our time indoors and so expose ourselves to these many airborne pollutants which can cause respiratory problems and other symptoms such as headaches, itchy eyes, sneezing etc. It is recognised that theseis are synonymous with high humidity levels.
By installing good ventilation, you can create an environment that is healthier and cleaner to work and live in whilst contributing to easing the building long term maintenance. But the question is what solutions are available?
Traditionally there have been powered ventilation systems (MV and MVHR) available for many years which whilst acknowledged as improving ventilation have two drawbacks: first, you obviously need power! which costs money, and secondly to be truly effective you need warm air (warm air collects more water vapour than cool air) and this is even more expensive.
An alternative product that has recently entered the UK market is the SolarVenti Ventilation panel. Designed manufactured and launched in Denmark in 2001, and already with 80,000 installations in 25 countries, the SolarVenti product offering is unique as it uses solar power to warm the air and power the fan, and so creating a zero-running cost system.
The SolarVenti fan produces a positive pressure within the property so allowing the moisture to be pushed out through vents or by natural air leakage.
The Science behind SolarVenti
Air that is warmed after passing through the SolarVenti panel has the same amount of moisture as when it entered the panel at ambient, but once the temperature of air rises above the ambient then its ability to absorb moisture rises and at higher temperatures then this ability to remove moisture rises dramatically (this can be as much as 60% higher than the ambient air). This is because warmer air has a greater space between its molecules and therefore is able to absorb water molecules. The warmed air acts like a sponge when inside the house absorbing the moisture in the air.
How SolarVenti Works
- Solar radiation starts the collector operation by initiating the patented internal solar PV panel which starts the fan
- Fresh dry air is drawn in through the small holes in the perforated back plate which are designed to prevent insect ingression.
- Solar radiation warms the patented material in the SolarVenti panel which not only exchanges heat and warms the air as it passes through the material but it also acts as a secondary filter removing particles and pollen.
- Depending on the model approximately 35 to 200 m3 of warm air is drawn through the patented material in the SolarVenti panel and blown into the building. The temperature in the injected air is approximately 15°C-40°C above the outside temperature dependent on the solar radiation – this can be adjusted through the SolarVenti regulator control
- Humid air is driven out of the building through an a vent valve or natural losses through the cracks and crevices of the building.
- Cleaning the panel of any debris is a simple process of switching the panel off for a couple of hours periodically on fine days and this raises temperatures sufficiently to eradicate the debris.
SolarVenti panels have been tested by has been tested by Fraunhofer Institute and the Danish Technical Institute, for both performance and durability. It has also received the Solar Keymark and energy saving awards.
In addition, the units have already won the 2016 New Zealand Building Industry highly commended award in the category Innovation for the Healthy School Project This award came after a year-long study of the positive effect of installing SolarVenti on classrooms by the Massey University of New Zealand which concluded:
“Our programme is investigating the benefits of improved ventilation on school classrooms in New Zealand. We have completed a successful pilot study using SolarVenti in 12 matched classroom (six schools) which has shown significant improvements in classroom climate and energy use. In 2017 we will begin a larger study where we will monitor the indoor environment in 50 classrooms which will provide us with nationwide baseline of the conditions in NZ schools.”
Professor Phipps who has been leading the research says: Analysis of the data is on going, but it could be an effective tool in reducing incidents of Streptococcus within New Zealand schools,”
Applications
SolarVenti offer a complete range of solutions from ventilating small properties all the way up to large commercial buildings.
Some of the reason people may want SolarVenti
- Landlords – There are stories of tenants switching off powered ventilation systems in an effort to save money. A real consequence of this is that condensation then builds up and so increases the demand for maintenance, which in a catch 22 trade-off is almost invariably more expensive, but potentially with someone else(the landlord rather than the tenant) footing the bill!
- Offices – Creating an environment that is comfortable to work in with fresh air ensuring less sick days and more productivity through greater concentration
- Education – The Massey University study has shown that children benefit from the better environment in the classroom, and this will be studied in great depth in the next year.
- Portable buildings and holiday lets – Offering free ventilation even when the property is unoccupied and so eliminating damp, mustiness etc.
- Indoor Swimming Pools – A great way to reduce the costs of running expensive ventilation equipment to achieve the correct atmosphere
SolarVenti has been installed from Greenland to Australia and is available exclusively in the UK and Ireland through NuVision Energy to find out more call 01404 891002 or got to www.solarventi.uk
This article appeared as the cover story for the November 2016 issue of Building & Facilities Management.
