English

The aim of this study is to accelerate developments of building simulation programs by using Object- Oriented programming. A reusable generalised scheduler classes and interfaces 1 ) for defining schedules in simulation programs were developed. ITermStructure2) the “interface” for a term structure was developed to make complex term structure general. By using a “Composite-Pattern”, all the  concrete term classes that implements ITermStructure could be integrated into a complex tree structure.

This paper presents simulations of the integral coefficients of performance of a heat pump system coupled with a vertical ground heat exchanger (GHE). The GHE is simulated using different assumptions concerning the heat transfer in the ground, heat exchange between the ground and the brine and vertical variation of the brine temperature. The differences in the predicted performance coefficients of the heat pump system using the GHE as the lower energy source are analysed and shown to be significant.

This paper shows the numerical model of an earth-toair heat exchanger. The system is discretized into “n” sections perpendicular to the exchanger pipe. In each section, conduction is solved using response factor method in order to reduce computational time. Each response factor is calculated using a finite element program that solves 2D conduction problems. The particularity of this problem is that time-constants are very high, making it impossible to use classical properties of response factors to reduce the number of calculations.

Common approaches to the simulation of Borehole Heat Exchangers (BHEs) assume heat transfer in circulating fluid and grout to be in a quasi-steady state and ignore fluctuations in fluid temperature due to transport of the fluid around the loop. However, in domestic ground source heat pump systems, the heat pump and circulating pumps switch on and off during a given hour; therefore the effect of the thermal mass of the circulating fluid and the dynamics of fluid transport through the loop has important implications for system design.

Seasonal storage of solar energy in geothermal boreholes has resurfaced as a means of heating housing communities. Typically, these systems operate at relatively high temperatures leading to high heat losses from the ground storage volume and to low solar collector efficiencies. In this paper, a new seasonal storage strategy is proposed. First, the storage temperature is kept relatively low in order to limit heat losses and improve solar collector efficiencies.

The transfer of energy from the ground to buildings through slabs and basements has long been a point of large errors in simulations. Work to increase the accuracy of this ground-coupled heat transfer was started under IEA Task 34/43. Detailed models of the ground heat transfer process were developed in TRNSYS for the IEA task work and refined further after for project work. The detailed models created for TRNSYS will be discussed in the context of the IEA task work as well as in comparison to the simplified methods used in mainstream energy modeling.

The user’s action is a decisive factor in the energy performance of a building. In this paper is demonstrated the necessity of using more specific user’s profiles (UPs) in simulations of building’s energy performance (EP).  The Spanish Technical Code for Buildings (CTE) offers a unique generic residential UP for all sites in the country. With the purpose of achieving more realistic UP, energy data, obtained during seven  years from more than 700 dwellings, are processed by advanced classification tools (Exclusive SOM).

The goal of this study is to evaluate the accuracy of the Portuguese thermal regulation simplified methodology for existing buildings and to assess the influence of different parameters on the building final energy performance evaluation. Simple “in-situ” measurement techniques were carried out to calibrate the input data in this methodology. The results obtained with the simplified methodology, with and without the input data calibration, were compared with the results obtained with the detailed methodology and it was concluded that the “in-situ” calibration could contribute to improve the

The general practice for establishing the consumption in asset ratings of a building consists of entrusting the energy analysis of the shell of a building to calculating software. The building is the subject of an extremely complicated analysis, and there are many variables at stake, is it more correct to aim for a simplification of the problem, in the knowledge that behind every analytical formula there is the possibility of an evaluation error, or is it better to aim for calculation models that are more and more detailed in an attempt to succeed in predicting the real energy behaviour of 

To address the functional complexities and volumetric variability found in the UK non-domestic building stock (Pérez-Lombard et al, 2008, Bruhns, 2008), the methodology for demonstrating compliance with energy performance criteria outlined in Approved Document Part L2A (ADL2A) allows the use of a variety of accredited simulation tools. This paper reports on the interim results of an intermodel comparative study that aims to investigate potential variability in results generated by the range of accredited tools available at the time of writing. An overview of the applicability limitations of