A flexible and low cost experimental stand for air source heat pump for Smart Buildings

Energy systems are faced with the challenges of reducing dependency on fossil fuels, while handling increasing penetration levels of intermittent renewables such as wind and solar power. At the same time, the efficient consumption of energy is vital for avoiding the impacts from increasing fuel prices. A significant part of this challenge may be dealt with in the way space heating, space cooling, and domestic hot water production which is provided to residential and commercial buildings. Air source heat pumps (ASHP) are widely used conversion technologies for providing building thermal energy services; cooling, heating, and water heating. ASHP does not have a constant temperature for the primary source like: soil, ground water, or surface water heat pumps. In result, laboratory experiments and tests are faced by the problem of having to handle a wide range of conditions under which the evaporator is operated. In order to cover various climate conditions, performance and behavior must be tested for temperatures ranging from -30°C to 40°C and for various humidity levels. This paper presents a state-of-art experimental stand, named controlled lab environment (CLE or climatic box), for testing ASHP under controlled evaporator ambient conditions. A main purpose of the CLE is to test and verify the performance and behavior of a theoretical model of the ASHP as a basis for optimization and efficiency improvements. Together with thermal storage technologies and intelligent control system this technology may come to play a key role in the development of Smart Buildings in future energy systems. While experimental results are not yet available the paper presents the design considerations and schematics of the CLE. Furthermore, a thermodynamic model of an ASHP is presented.