Bagergaarden in Haderslev has solved its moisture problem and reduced energy costs
Moisture is a big problem when freshly baked bread goes into the freezer. H.C. Andersen Bagergaarden A/S in Haderslev (Denmark) knows this all too well, as their storing and delivery of Kohberg's bread and buns result in the cold room's gates being open a couple of hours a day.
- We had too much moisture in our cold rooms, resulting in large expenses for defrosting. The moisture created, amongst other things, a layer of frost in the ceiling that fell onto the boxes, which became damp when they left the freezer. The ice crystals created on the strip curtain at the entrance also posed a work environment problem, explains bakery manager Teddy K. Jensen.
He therefore considered creating a room where the moisture could be removed continuously before reaching the cold rooms.
- However, this solution would result in much higher operating costs. So, when I heard about air curtains possibly being a solution, I asked Frico to put together an offer, even though I was sceptical. I understood that the air curtains could create a barrier between the cold and the hot air, but could they also keep out the moisture? We started by installing just one air curtain – and it worked. The ice crystals on the strip curtain completely disappeared, and if we turn off the air curtain, we can see how fog is immediately formed by the gate, says the bakery manager.
Quick pay off The bakery has now installed several air curtains by both the gates and other entrances, and one of Kohberg’s larger cold storages in Haderslev is also about to acquire air curtains from Frico. Bagergaarden has invested about 200 000 Danish crowns (approx. 27 000 euro) in this solution.
- It is important not to forget the energy savings. It is very expensive to defrost a cold room, so we are expecting a pay off period of two years.
The effect can be calculated in advance Before and after the installation of the air curtains, Bagergaarden let the energy company Ørsted measure the effect. Actual savings on the first air curtain were calculated to be 30 MWh annually. It is also possible to calculate the effect in advance. Energy consultant Kasper H. Biermann at Ørsted explains how the measurements are done:
- When the door between a cold room and a warm room opens, an air flow is created between these rooms. The air moving from the heated to the cold room contains water vapor, which condenses and freezes to ice. Based on the air flow, how long the door is open and the relative humidity, it is possible to calculate the amount of energy used to convert the water vapor to ice. Lastly, the stated output of the air curtain is deducted to produce the result.