Abstract

The preschoolbuildinng Graningegården was buildt in 1974 and is today in need of a new

heating- and ventilation system. Todays heating system, with radiators using electricity as a

heatsource and with a control system that doesn’t work as intended, is an expensive soloution

due to high electricity costs.

A new system would be favourable, partly because the lack of heatrecovery in some parts of

the ventilation system, and partly because of obsolete control system. A modern control

system will make sure that a certain zone in the building only is ventilated when needed, that

is, when it’s occupied.

This would, with today energy prices in mind, have large economical benefits.

We have with Arvika kommun as principal, carried through this project whith the purpose to

examine the possibillitys of a construction of a modern heat- and ventilation system in the

building. Arvika kommun is about to renovate the heat- and ventilatinsystem on

Graningegården, and an amount of money is earmarked for this project.

The project is initiated in collaboration with Per-Inge Andersson, our contact man at Arvika

kommun. The building is analyzed regarding heating and ventilation loads and an energy

balance is calculated. The results from the calculations, has helped us to find two proposals

for the heat- and ventilation system at Graningegården.

The first proposal has a complete mechanical exhhaust air system, and a partly mechanical

supply air system combined with supply air through the facing of the building (F-system).

The second proposal has a complete mechanical supply- and exhaust air system in a more

traditionell way (FTX-system). Both these systems is meant to be combined with a boiler

using biopellet as fuel and a hot water radiator system. The solution with some of the supply

air trough the outer walls is also completed with a heatpump using the exhaust air as a

heatsource.

Both our proposoals will exceed the budget, but they will both also have a payback time at a

few years, this because of a more efficient use of energy together with a contribution of 30

percent of the cost at the heating system (the contribution comes from the government, and is

meant to ease an change to a more energy efficient heating system).

With these two proposals in mind, we would like to recommend Arvika kommun to invest in

the F-system. This because it has a little bit lower investment costs, and it also costs a bit less

to run.