With the continuing growth of large supermarkets and distribution centres requiring a controlled environment, it is imperative that we gain a greater appreciation and an increased understanding of such critical issues as energy performance, build-ability, safety, and sustainability. Informed ‘building envelope’ material selection can ensure the highest standards of the above criteria are met and even exceeded, saving money and time and cutting down on carbon emissions too.
‘Controlled environments’ is the generic term used to describe a range of spaces that require a set of parameters such as cleanliness, temperature and air circulation to be maintained at a precise level so as to ensure that activities can be carried out without any negative impact from the external environment.
If we start with some basics, in the case of a typical food storage or preparation area for example, the wall and ceiling specification clearly needs to meet the primary purpose of keeping goods at a particular temperature and moisture content level, so the construction must be capable of dealing with a whole range of different conditions externally whilst consistently maintaining that all important internal environment.
The next performance consideration is how effective the building envelope material is at keeping running costs to a minimum. Saving energy and cutting CO2 emissions are a vital part of any construction project today. Controlled environments (particularly cold rooms) tend to consume significant amounts of energy and the greater the thermal efficiency of a modular box or controlled environment both in terms of insulation and air tightness, the larger the savings. Even small improvements in thermal efficiency can contribute to significant savings over the life time of the building.
Insulated panels are considered the most efficient and effective wall and ceiling material to use in a controlled environment, however, a variety of insulation core options are available including polystyrene, Polyurethane and PIR (polyisocyanurate). High quality PIR panels perform the best overall in terms of sustainability, fire performance, thermal performance aligned to weight and thickness and efficiency of build. Kingspan PIR Controlled Environment panels are world leaders in this area.
Kingspan Ecosafe PIR core for example has a thermal conductivity of 0.0195 W/mK giving a class leading thermal efficiency. The practical implication of this superior thermal efficiency is that by using a Kingspan controlled environment panel, the amount of external conduction or heat gains is less compared to those using PUR or other core materials of equivalent thickness. For a cold store operating at -30°C the heat gain by conduction through 150mm thick Kingspan Ecosafe PIR insulation with an external temperature of 30°C would be 7.80W/m2. The equivalent heat gain by conduction for PUR would be 8.80W/m2, 14.8W/m2 for EPS and 16.0W/m2 for MF. Conversely, to maintain a maximum heat gain by conduction of 10 W/m² as recommended by The Institute of Refrigeration, can be achieved with a relatively thinner and lighter panel, resulting in lighter substructure and more usable space. The greater thermal efficiency means the impact on the cooling load will be less and direct saving on energy costs.
Hygiene and contamination
Maintaining hygiene levels and preventing cross-contamination within controlled environments is critical. This can only be achieved through certified coatings and materials that guarantee food-safety, absolute cleanliness and a fibre-free environment.
By using a closed cell core product, such as superior PIR foam, it is possible to resist the ingress of moisture and any risk of toxic mould or bacteria growth. FoodSafe coatings, such as those found on Kingspan panels, are specifically designed for hygiene and there is therefore no risk involved for building’s or employer’s liability insurance cover, regarding the presence of toxic mould.
In these environments it is important not to forget seals and joints and specifiers, designers and contractors place high importance on panel joint design. Joints between individual panels and trims have to be effectively sealed to the same hygiene specification standards.
The weight of panels should be an important factor. Both in the cases of modular boxes and whole buildings, the weight of panels has a significant impact on build speed, labour requirement for the build, safety on site and the use of any machinery during the construction.
As the thermal efficiency provided by PIR foam is so much better than mineral fibre core panels, thinner and significantly lighter panels can be used. The lightweight nature also enables panels to be manufactured in longer length, with Kingspan they go up to 11.8m, which reduces the number required, increases the speed and efficiency of the build and reduces cost – all while maintaining the excellent U value rating and structural integrity.
There are many factors to consider when creating a controlled environment, these above are just a summary. If you would like more information on anything relating to controlled environments then please contact me on firstname.lastname@example.org