Banish the winter blues

A guide to sustainable warehouse heating

An uncomfortably cold warehouse is bad for productivity. It may also affect the condition of your employees, equipment, building and stock. Mark Nicholson offers advice on how to maintain the right temperature – efficiently and sustainably.

In most countries, there’s a need for heating at least during the winter. Shivering workers are unhappy and don’t perform so well. A chilly work environment can even lead to illness. In the longer term, those staff might leave to join a company with better working conditions.

Your machinery, including lift trucks, may be adversely affected by a cold workplace too. It can reduce the effectiveness of lubricants, for example. A side effect of low temperatures may be condensation on the surfaces of equipment, building structures and stored products. This dampness could cause rusting of metal, deterioration of walls and wooden features, and growth of moulds. At the extreme, wide temperature variations can make concrete crack. Although some fresh produce may benefit from keeping the air cool in its part of the warehouse, other goods may do better in a warmer storage area.

When deciding on a heating system, you must take these factors into account. At the same time, it makes sense to consider your energy costs, your carbon emissions and your company’s reputation for environmental responsibility.

Choose an efficient and green power source

Burning gas or oil is highly effective in producing heat – but this is clearly a source of carbon emissions. Using biofuels can reduce the impact. Meanwhile, the latest technological advances are increasing the efficiency of fuel-burning systems and lowering their emission levels.

Electricity is the greenest power source, as long as it’s generated renewably. You can buy in green electricity produced by wind, sun, hydro and other sustainable methods. Better still, try to generate at least some of it yourself, with solar panels or wind turbines on your site.

You can make the electricity go further by installing air source or ground source heat pumps. They work using similar principles to those of refrigeration and air conditioning systems. In this case, they extract heat from the air or ground and pump it into the building. Even if it seems cold outside, there is still heat to be captured. The pumps do consume electricity, but in return they give you up to four times as much energy in the form of heat. Air source pumps can be reversed in summer to provide air conditioning.

You can save on your bills and avoid wasting precious energy by holding in the heat.

Find the most suitable heating system

There are two main heating choices for warehouses: warm air heating and radiant heating. With warm air heating, you use an oil-fuelled, gas-fuelled or electrically powered system to heat up air. Then you blow it into your warehouse space. This is the most common approach to warehouse heating. It’s economical, effective, well proven and ideal for keeping large spaces warm.

Radiant heating works by emitting waves of infrared radiation. These can be generated by oil, gas or electric power sources, depending on the system. The electrical options include quartz halogen heaters. Infrared radiation heats up objects – including people – on which it falls. It doesn’t heat the air in between. Obstacles such as high-density racking, between the radiator and the object, can stop the radiation from reaching its target.

In more open areas, radiant heating works well. It’s also great for locations where warehouse doors are frequently opened and closed. While air heating systems are disrupted by this, radiant heating continues to keep the area warm. Radiant heaters are often suspended on the ceiling or walls. Another option is radiant floor heating, with heaters at subfloor level.

Circulate your heated air

Hot air rises. In warehouses with high ceilings, much of the heat can end up way above the workers’ level. The result is temperature stratification, with the upper levels warmer than they need to be and the warehouse floor level still cool. The answer is to use destratification fans. Today’s HVLS (high volume, low speed) fans are ideal.

HVLS fans have unusually long blades which move large volumes of air, more slowly and efficiently than conventional systems. Their action sucks warm air from above the fans and pushes it down towards the floor. This, in turn, draws cool air from lower areas up to the ceiling. The result is effective mixing and an even distribution of heat. The air circulation it creates also overcomes obstacles to hot air movement, such as dense racking.

Thanks to their air movement and temperature equalisation, HVLS fans minimise condensation. They also improve air quality. In summer, the same fans economically supplement the cooling effect of your air conditioning system.

Create temperature zones

Different parts of your warehouse may have different temperature and heating needs. The ideal solution may be to divide your building into zones. Some will require warm air heating. Others may be better served by radiant heating. Combining the two types is certainly possible.

An area visited only occasionally doesn’t need to be so warm. Offices and packing or sorting areas may need to be warmer. Areas of intensive loading and unloading activity could be left a little cooler. Fresh produce may require a cool location.

In a warehouse heated mainly by warm air, you could supply supplementary spot heating for small zones that need to be warmer. You can do this with radiant heaters or space heaters, including portable units.

A further approach to reducing your heat energy needs is to automate some parts of your materials handling operation. In the automated zones, temperatures can be a bit lower. Automating movement of goods in and out of a refrigerated area has an added benefit. It allows the doorway to be made much smaller, which helps with insulation.

Insulate and control

You can save on your bills and avoid wasting precious energy by holding in the heat. Large warehouse doors and windows are typically the biggest gaps in warehouse insulation. Windows should ideally be double-glazed, and you should check their seals for leaks. Specialised industrial door companies can supply insulated doors. Door opening and closing speed is another factor. High-speed doors minimise heat transfer when people and trucks pass through.

For dock doors, a good fit between the door aperture and the goods vehicles minimises heat escape through surrounding spaces. Dock shelters help to reduce those losses during loading and unloading, and the best designs provide a tight all-round seal. A relatively simple extra aid to doorway insulation is a PVC strip curtain. Similarly, industrial curtains can help in separating temperature zones.

Finally, you should control your heat inputs carefully to achieve optimum temperatures without wasting energy. Timers can be programmed so the warehouse is pre-heated just in time for the workers’ arrival. They will then turn the heating down (or off) at the end of the day. Automatic controls can adjust the pre-heating period and the continuing heat input to compensate for outdoor temperatures.

For more energy-saving tips, visit:

www.catlifttruck.com/blog/save-your-energy