IBPSA1999

Coupled heat and moisture transfer equations which describe temperature and moisture fields in the building walls, the earth ground and so on are nonlinear. Due to the nonlinearity, the complicated analysis has to be performed in each time under the different boundary values. If linearization of the system with adequate accuracy can be achieved, a solution can be obtained simply by applying the superposition principle.

Object-oriented or modular simulation methods represent a concrete alternative to present monolithic building simulation technology. Modular methods have previously been used primarily for component based systems modeling, while envelope models have remained monolithic. In this paper, the advantages of the new technology are reviewed and an equation-based models library for systems as well as envelope modelling is introduced. The new library has been developed within IEA SHC Task 22 and is available as NMF source code. Airflow network models are combined with thermal.

The UC Berkeley Multinode Comfort Model is based on the Stolwijk model of human thermal regulation but includes several significant improvements. Our new model uses sixteen body segments (compared to six in the Stolwijk model) corresponding to the UC Berkeley segmented thermal manikin. Each segment is modeled as four body layers (core, muscle, fat, and skin tissues) and a clothing layer. Physiological mechanisms such as vasodilation, vasoconstriction, sweating, and metabolic heat production are explicitly considered.

A study was performed on a method to evaluate performance of window system necessary to satisfactorily maintain the window side radiation environment in a glass building. On general type window using high-performance glass, air flow window and push-pull window, U-factors and SCs in various specifications were obtained from numerical calculation. Also, a simulation model for indoor radiation environment is proposed using the newly defined window thermal property values.

This paper presents a new, accelerated method based on GD\OLJKWFRHIILFLHQWV according to Tregenza [1] to calculate cumulative annual indoor illuminance distributions. Simulation results are compared with five RADIANCE based daylight simulation methods including the daylight factor method [2], ADELINE 2.0 [3] and ESP-r version 9 series [4]. An explicit calculation of the indoor illuminances under all annual hourly mean sky luminance distributions serves as a reference case against which the other methods are tested.

This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space. The system was introduced into a real building (Aichi Children’s Center in Japan) and was examined by the field measurement.

An absorption chiller model is developed for HVACSIM+(J). The model simulates dynamic characteristics of the chiller, such as dynamic trends of chiller temperatures and COP. The total system simulation including the chiller and the other HVAC system enables to evaluate energy consumption for the HVAC systems and how much the system save energy. Furthermore, the simulations show the effect of the control strategies. In the paper, the chiller model is described, and the simulation results which contain independent chiller system and a total HVAC system.

In multizone models used to predict thermal comportment of buildings and inside air quality, representation of the airflow through large vertical openings is very important. Both physical representativeness and numerical stability of the large opening model are essential for a successful multizone modelling.

We developed a PC-software to estimate thermal environment of a residential house. To make the software practical for non-technical people, the easiness of operation was our main interest in this development. This led us to adopt a fully graphic interface, dynamic database of the structural walls and a comparative output of the thermal estimation. As a result of error comparisons within various numerical methods, we decided to use the full implicit finite element method to calculate the transient heat flow in the walls.

A systems approach is developed for predictive operation of HVAC processes in buildings, which is described with an objective function, a state-space model, and a number of constraints. The state-space model is transformed from z-transfer functions that are identified in real-time. The system constraints are described mathematically so that they can be easily applied. Dynamic programming techniques are combined with on-line simulation to enhance efficiency in searching for the optimal operation strategies. Simulation studies show that the techniques are computationally efficient.