The average outside temperature in the Swedish city of Kiruna is +1,2°C and the energy needed to keep the indoor temperature at 18°C at a restaurant is 215.000 kWh per year.
In Birmingham the average temperature is 10,3°C and the average energy demand for heating is 110.000 kWh per restaurant/year.
So how come a restaurant in Kiruna only pays 50% of the cost that a restaurant in Birmingham pays for heating, even though the indoor temperature and the cost per kWh is the same?
|City||Avg temp||Energy demand||Yearly cost @ £0,35/kWh|
The short answer is: In Sweden we recover the heat from the kitchen ventilation and use this heat to warm up the supply air going into the building.
By placing a modified heat exchanger (Lepido) in the kitchen ventilation duct where the air is hot, we can recover energy that’s currently being wasted. We use this energy to warm up the supply air going into the building, cutting 90% of the demand for purchased energy.
That means that even though a Swedish restaurant has a demand for 215.000 kWh/year to keep the restaurant warm, it only needs to purchase 54.000 kWh/year. At the UK restaurant with no recovery unit in place, all the 110.000 kWh needs to be purchased.
From £33.000 to £3.300 per year.
Using this Swedish way to recover energy is extra beneficial in the UK, as the average outside temperature is higher. That means that the energy recovered by a Lepido can cover up to 90% of the energy needed to keep the UK restaurant warm.
|Solution:||Energy demand||Purchased energy||Yearly cost|
|No recovery||110.000 kWh||100%||£33.000|
The result: A UK restaurant can save up to 90% of their heating cost by using the Swedish way to recover energy.
Download project data here :LINK