Simulation Based Assessment of Heat Pumping Potential in Non-Residential Buildings – Part 3: Application to a typical office building in Belgium

The purpose of this paper is to describe the application of the tools presented in a companion
paper [1] to a typical office building located in the Walloon Region of Belgium. This building
is a mid-size (7000 m² on seven floors) office building constructed in the eighties and
equipped with a classical HVAC solution: boiler and air-cooled chiller; all-air VAV system.
An energy audit was conducted in this building and featured a number of management
problems. Among the Energy Conservation Opportunities considered to improve the energy
performance of the building, the move to a heat pump solution was considered.
The identification of energy savings potential offered by the implementation of heat pumping
strategies confirmed what was already shown by the parametric analysis: in temperate
climates, reversibility offers a by far higher potential than condenser heat recovery given the
dominant non simultaneity of the yearly heating and cooling demands profiles. Calculations
show that theoretically half of the heating demand could be satisfied by the reversibility of the
chiller to run in heat pumping mode.
In a second step, a number of practical implementations of heat pumping solutions were
evaluated by means of another software tool: reversible air/water HP, exhaust air HP, double
condenser and water loop heat pump systems. These solutions are compared to the reference
existing situation (boiler + chiller working independently) in terms of energy, CO2 emissions
and cost on a 20 years life-cycle basis. Calculations show that the air/water reversible chiller
solution offers the most important energy savings and CO2 reduction while staying at a
reasonable level concerning the additional cost.