- Energy Saving
Is your cold store leaking energy?
Energy losses are the unseen costs of any cold store. Heat gain through the structure and air leaks can have a huge impact on a grower's profitability — whether storing carrots, onions, flowers or any other horticultural crops. And with electricity prices on the rise, minimising the cost impact of energy waste is all the more important.
But before anything can be done to remedy energy waste, it first has to be identified — which is where the problem lies. If an irrigation line were to spring a leak, you'd clearly see where the water was leaking from and know where it needed work. Unfortunately, energy leaks in a cold store aren't quite so easy to see ... but there is a solution!
A thermal imaging camera is an excellent tool for identifying energy loss areas in a cold store, and illustrating the common areas where energy efficiency could be improved, both inside and outside of a building.
A thermal imaging camera takes a thermal ‘photograph’ of an area, which shows variations in temperature as changes in colour on the image. Wherever heat transmission is taking place, there will be a change in temperature and, hence, a different colour. Colder areas show in blue and warmer areas in red.
The pictures below show thermal images taken from inside and outside a cold store, and show examples of faults commonly found in many cold stores. If taken inside, most of the cold store structure is blue, indicating that it was cold, whilst the problem spots show up as red or orange indicating they were warm. If taken outside, the colour gradient reverses with the problem spots showing up as blue or green.
These are not the easiest areas to seal, because they are there to provide air flow. This thermal image was taken from outside the cold store. The right-hand side of the louvre is at 7 degrees C, whereas the left-hand side is at 12 degrees C.
Further investigation revealed that dirt / debris and a dislodged brush seal were causing the problem — and after a simple repair, the problem was rectified.
Taken from the inside, this thermal image shows a hot spot along the gap between the door and the store structure.
The main body of the door is 10 degrees C, compared to 16 degrees C at the hot spot.
In this case, there was an obvious gap between the door and the frame. At the very least, all doors should have close-fitting brush seals — even if they have to be replaced every year.
Here, a steel beam is providing a ‘hot bridge’ to the warmer conditions outside. The beam is at 15 degrees C, whereas the rest of the store is at 4 degrees C. This is a common mistake when insulating existing buildings to convert them into cold stores.
This is where most structural heat gain often occurs — especially on a sunny day.
Here, the insulation looks fairly sound, although hot spots show up at the joints between the insulation panels. This highlights the attention to detail that is required during cold store construction.
To see the effects of solar gain, this thermal image was taken from outside the cold store.
Even though it was a cloudy day in May, the image shows the cladding is at 17 degrees C on the right-hand side. In contrast, the left-hand side — which is in the shade — is only 13 degrees C. This shows the impact of solar gain, even on the most unlikely of days.
Light colours on the outside of buildings help to reflect solar radiation, but this can conflict with planning requirements.
Finding a solution
These examples show how a thermal imaging camera can identify the hidden culprits that are wasting energy in your cold store and increasing the costs of produce storage.
In most cases, the solutions are simple and will give quick paybacks. Remedial work could save up to 20% in total energy use. Whether it is repairing insulation, sealing gaps around doors or carrying out simple repairs and maintenance, you will see the rewards for many years to come.
Having a themal imaging survey done will help to reduce costs and ensure your produce is stored at the required temperature.