One of the basic principles of physics is that
hot air rises.
What is destratification and how does thermal stratification affect our working and living environments?
This basic, yet fundamental law of nature can cause major problems for companies attempting to maintain temperatures evenly throughout their buildings for customers, staff and stock. Inefficient heating and air conditioning systems are both costly and wasteful. Air temperature differences can seriously affect the shopping experience, or employees’ working conditions. Occupants in one area may be complaining about the heat while those elsewhere will be too cold.
Temperature differences can also play havoc with the design of racking systems in temperature regulated storage facilities where constant temperatures are required. This is especially true in refrigerated facilities where cool temperatures are needed in order to preserve the quality and maintain the lifespan of the goods that you are storing. Excess hot or cold storage conditions can affect the ‘shelf life’ of many types of goods.
The problem occurs due to the creation of natural thermodynamic layers or ‘thermal stratification’. Warm air is lighter than cold air so will naturally rise. Or more accurately put, cold air is denser and heavier than warm air. As it is heavier it sinks, which pushes the warmer air up. This creates a rising gradient of temperatures from warmest at the top to coldest at the bottom – Thermal Stratification. Many buildings may not have good quality airflow systems: hotter layers naturally form at ceiling level, with cooler layers remaining at ground level. The larger and more open the space, the more problematic thermal stratification can be. (Find out more about the process of stratification and evolution of destratification fans here – The Missing Piece To The HVAC Puzzle)
Many commercial, industrial and retail spaces have open high ceilings which allow business tenants to use the space in a way that suits their needs. Mezzanine floors are very common. They are frequently used to create separate work-spaces for staff and to distinguish the different functional areas of the business. This kind of flexible space utilization can exacerbate the issues due to the dramatic differences in temperature between different areas of the building.
In buildings taller than 4m, ceiling temperature layers or
‘strata’ are different to those at ground level where conventional thermostats
are usually placed. The temperature
difference between the layers can be substantial depending on the design and
architecture. The higher and more open a building is, the more likely it is to
face issues with thermal stratification.
Heating and/or cooling buildings effectively and efficiently
requires a specialist solution, and this is where destratification systems can
Destratification systems are designed to stir up the airflow in a space. Powerful targeting fan systems constantly mix all the air within the building, forcing the warmer air back down to ground level and breaking up the temperature strata. This continuous recirculation of airflow results in all temperatures being mixed evenly. This results in a more constant temperature throughout. Subsequently this reduces energy bills and it is easier to maintain comfortable work temperatures for all your customers and employees.
When it comes to thermal stratification, there are two issues that business owners need to be concerned about:
According to The Carbon Trust, destratification systems can cut HVAC energy consumption by up to 20%, but customers employing the next generation of axial turbine destratification fans are seeing reductions in excess of 50%. Investing in destratification technology can have financial benefits in the long term and help your company to ease its environmental conscience. Most businesses will recoup the cost of their destratification system within 1 – 5 years. In many cases payback has been within a single season, whilst in one case it was as little as 1 month – Lush Cosmetics Saves 60% On Heating In 1 Month.
Destratification systems optimise heating by capturing the
heat at the higher ceiling levels and forcing it downwards. To optimise cooling the fans are installed
lower than the ceiling height and focus on circulating the cooled air supplied
by air con systems evenly within the space. In some cases, the controlled air
movement generated by the fans is sufficient to provide cooling in the UK and
similar climates. The more efficient the design and engineering, the more effective
the solution is and the bigger the savings.
Energy use is much lower, and temperatures in the workspace are more
tolerable for everyone.
In recognition of the green benefits of installing a modern and energy efficient destratification systems many governments and finance providers offer subsidised (or otherwise incentivised) financial packages designed to encourage take up. For example, in the UK, Salix Funding offers 0% financing on eligible systems. And, across the EU, ERDF (European Regional Development Fund) funding is available for energy efficient projects.
If you are thinking of investing in a destratification system for your business, then there are a few things you need to be aware of:
Fans need to be perfectly positioned to be most effective
If fans are not positioned correctly in relation to the environment, floor area and activity below, airflow will not circulate effectively. If fans are too low in heating applications, they can cause unwanted draughts. If the fans are too high in cooling applications, they aren’t harvesting the cooler air below. Systems that offer the option to vary the air velocity can help to resolve this – so look for a manufacturer that can provide surveys and detailed installation guides, along with variable controls which will allow you to control airflow speed to meet the needs of your business.
Workspaces and noise levels
fans can be noisy so make sure you advise your installer about which areas have
high staff volumes or static workers and which brands will be most effective
for the space. There are some brands of destratification fan that supply
solutions specially designed for noise sensitive areas. These use the latest EC
fan motors which operate near silently.
It is important to get professional advice to make certain
that the system is perfectly designed to suit your space. Remember, not all technology will work
effectively in every situation so it would always be wise to speak to experts
and work with them to develop the most efficient system for your business.
Airius are a UK based company dedicated to the design and installation of world class thermal destratification fan systems. Formed in 2004 and covering Europe, Africa, the Middle-East and Asia, with offices in the USA and Australia – we pride ourselves on our customer service and the quality of our products and installation, giving a 120 day no questions asked full money back guarantee, offering customers the extra reassurance and peace of mind needed when making an investment.