English

Detailed simulations of two hotels have been carried out, to determine whether CO2 emissions can be reduced by 50%. The hotels, one older and converted and the other newer and purpose-built, were chosen to represent the most common UK hotel types. The effects were studied of interventions expected to be available in 2030 including fabric improvements, HVAC changes, lighting and appliance improvements and renewable energy generation. The main finding was that it is technically feasible to reduce emissions by 50% without compromising guest comfort.

As plant modelling becomes capable of more complexity and detailed resolution, new opportunities arise for the virtual evaluation of discrete plant components such as flow control and energy conversion devices, and controllers.

For the purpose of reducing the room air-conditioners’ energy consumption, an energy saving control method is proposed formerly. In this paper its energy saving effect is confirmed through experiments conducted in six office rooms in actual use. The experiment results show that the air-conditioners controlled by the present energy saving control logic and parameter settings can save electric power up to 3.0% compared to ordinary control.

To reduce the potential problems of window systems such as undesired heat gain (loss), glare, and thermal discomfort due to asymmetric radiation, double-skin systems have been introduced. The current problem with double skin systems is that their operation requires an adequate simulation model to realize optimal control of the system. The estimation of the parameters in the lumped model developed in a previous study (Park et al 2004a) was based on ‘laborious’ off-line calibration procedure.

Study of complex control strategies plays an increasing role in building design. Discrepancy between the intentions of the designer, often expressed as nonformalized control laws, and the as-built implementation is a frequent source of malfunction and energy waste.

This paper presents Artificial Neural Network (ANN)-based predictive and adaptive thermal control strategies for residential buildings designed to advance thermal comfort. For residential buildings, we developed a thermal control strategy framework, with four thermal control logics therein, including two predictive logics with ANN models incorporating the Neural Network (NN) toolbox in MATLAB. Using computer simulation with International Building Physics Toolbox (IBPT), a typical two-story single-family home in the U.S. was modelled for testing each logic’s performance.

Energy efficiency improvements of renovated district heating and cooling (DHC) plants were evaluated by simulation. In this paper, the simulation models for the original and renovated plants are developed based on the equipment specifications of the original plant. Accuracy of this model is examined based on the comparison of the measurement data from the operations of the original plant. From the result of this comparison, few parameters related to the chiller operational control and chiller efficiency were modified.

A model for simulating clusters of standing column wells (SCWs) for use in geothermal heating and cooling systems is described in this paper. The model is three-dimensional, dynamic and solves the governing equations using a finite volume discretisation scheme with a fully implicit algorithm. The slower-acting field equations are solved using a wider time interval than that used for the faster-acting well equations and the two sets of equations are coupled through the field equation source terms. A groundwater bleed feature is incorporated.

Since district heating (DH) is the dominating heating system in Scandinavia, and fairly common in large parts  of Europe, it is of vital interest to study the possibility  for buildings connected to DH to receive heat during an electric power failure. Our studies have proved it possible to achieve natural circulation in space  heating systems indirectly connected to DH if the DH network operation can be maintained. Natural circulation in modern heating systems has been simulated. The model shows good resemblance with field studies.

Combined generation of thermal and electrical energy in units with electrical power less than 10 kW provides an attractive option for the energy supply of residential buildings due to their potential to high overall efficiency and thus capability of reducing emissions. Dynamic simulations of such systems are required to performance assessments that aim at finding the most energy efficient system topologies. This paper presents the implementation of a  combustion engine-based micro-cogeneration routine into IDA-ICE, which is a widely used building simulation program in the Nordic Countries.