The flexible solution to indoor climate control
Louise Harris, UK Brand Manager for Zehnder, discusses radiant technology and highlights the range of benefits and advantages it is able to provide to both the building owner and the user.
The provision of a continuously comfortable indoor climate within commercial buildings can be affected by a wide variety of factors. For example today’s building regulations, with their drive for low carbon design, plus modern materials and methods of construction are making buildings more airtight and subsequently more prone to overheating. The long-term impact of climate change is also playing a part as we experience more extreme weather conditions. Also not forgetting the human element, where systems are tampered with or windows opened, preventing systems from operating correctly. These factors, plus others, make the everyday management of an indoor climate increasingly challenging.
What’s more, with energy prices continuing to rise year on year, and additional increases predicted for the future, the financial burden of providing a comfortable working environment for building occupants has become an even greater concern for Building Managers.
One HVAC technology which provides extremely flexible and cost effective year round climate control, but which is also often overlooked as a complete indoor climate solution, is radiant heating and cooling.
The radiant solution
When it comes to energy efficiency radiant technology leads the field and is able to outperform its contemporaries by as much as 40% in commercial buildings. Thanks to the high radiant values and the combined perceived temperature in a room, the air temperature within a radiant heated or cooled room can be up to three degrees lower or higher than that of an alternatively heated room whilst giving the same sense of comfort. This enables quicker response times to temperature fluctuations, reduced infiltration losses and a more even temperature distribution with a resultant better working environment. In addition the lower air temperature means direct energy savings and lower carbon emissions. Figure 1 shows the different temperature profiles of a radiant heated building and an air heated building.
The combination of higher radiant values and lower air temperatures also results in less convection. The greater the air mass the longer it takes for convection to work and the greater the energy needed. Therefore with less convection the opposite is true, making the operation of radiant panels more efficient. It also means lower dust levels, which is beneficial to allergy sufferers, and helps save on cleaning and maintenance costs.
Thanks to innovative material technology, such as the use of natural graphite within the thermal element, the reaction time and controllability of radiant panels has become extremely fast. This high level of responsiveness is particularly important for today’s buildings as being extremely well insulated, even small fluctuations in heat load can result in major temperature fluctuations for users. Thanks to the lower mass rate and excellent conductivity of radiant panels they are able to react immediately to changes in room temperature and to the hot or cold water entering the panel. This significantly reduces warm up and cool down times and ensures exceptional flexibility in temperature control. Again this translates into lower running costs and lower emissions.
The ability of radiant panels to react so quickly to changes in the indoor climate means that they are ideal for multi-use buildings i.e. colleges, community centres or training facilities, where different rooms are likely to have different requirements throughout the day. It also makes them suitable for large commercial spaces such as warehouses or distribution depots, where basic operating practices such as opening and shutting doors can significantly affect the overall indoor temperature. By responding automatically and promptly to changes in temperature the radiant panels ensure a continually comfortable climate for users at all times.
The low storage mass of radiant systems means that they are also ideally suited to operating at low temperatures. This makes them compatible with renewable technologies such as solar, biomass or ground and air source heat pumps, and provides a fully sustainable alternative for commercial properties. In fact by running at a flow temperature of 30°C radiant panels use around 90% less energy than a system running at a flow rate of 50°C, greatly reducing energy costs and carbon emissions.
By far the most practical advantage of radiant technology over alternative climate control systems is its ability to offer dual functionality, with the provision of heating and cooling from just one installation. This reduces equipment and installation costs whilst also creating a safer environment by eliminating the need for low surface temperature radiators and preventing the possibility of accidental or deliberate damage to radiators.
From an aesthetic perspective the dual functionality offers additional benefits. Fitted within or below the ceiling the panels can be incorporated into the overall room design, thus optimising valuable wall space and negating the need to cover unsightly pipe work. There are also no radiators to paint or maintain and cleaning costs are reduced as less air is circulated.
Installation and maintenance
In addition to their efficient running costs radiant panels also offer many installation benefits. Designed to be used in all large spaces, up to a ceiling height of 30m, radiant panels are extremely lightweight and easy to install. Available in lengths of up to 7.5m they are ideal for long runs, and being modular in design can be quickly connected by means of press/screw fittings to help reduce time spent on site.
Individually manufactured and tailored to the requirements of each building panels can either be hung independently, making them extremely flexible in design, or fitted directly into an existing grid ceiling, making them ideal for retrofit installations.
They are also made from corrosion-free materials so require little or no maintenance, providing long term peace of mind for building owners and can be fitted with integrated lighting, acoustic insulation and other special solutions to further reduce time spent on site and increase functionality. Unlike air conditioning radiant panels are draught free, silent in operation, and unaffected by humidity for a fit and forget solution to indoor climate control.
With budgets stretched and the need for energy efficient and cost effective indoor climate solutions key to the requirements of building owners and users, radiant technology offers an extremely practical and intelligent option. Working in response to the actual air temperature to either heat or cool the building as necessary, radiant technology provides an extremely controllable indoor climate. Its flexibility in design, installation and operation enable it to work in tune with the building and ensure a continuously comfortable environment for users.
In short, providing a functional and energy efficient solution to temperature control in large spaces, radiant technology offers a comprehensive year-round solution with maximum benefit and minimum cost.