Throughout its thirty year history, the transient energy simulation package TRNSYS has been under continual enhancement by an international group of developers and users. This paper briefly describes a subset of the features that were added to the simulation package with the release of its 16th version in November, 2004. 

This paper is part of a larger research to ‘theoretically’ review the application of natural ventilation to commercial buildings, the potential advantages these systems offer, and some pitfalls that must be considered.

A mathematical model applied to building hygrothermal behavior analysis is described in this paper. We have used a lumped approach to model the room air temperature and humidity and a multilayer model in finite volumes for the building envelope. The capacitance model allows studying the dynamic performance of both humidity and temperature of a building zone when it is submitted to the different climatic factors. In the results section, we show the moisture effects on the heat and mass transfer through the floor and ground.

Controlling humidity to prevent moisture and condensation phenomena is a growing problem for building designers nowadays. Ventilation and air conditioning are common solutions to avoid mold and condensation. However, to promote low cost energy buildings, an alternate solution may be to decrease the daily variation of humidity with anti fungi treated absorbing material.

Ground source heat pumps (GSHPs) are modelled, analyzed based on exergy, cost, energy and mass, and evaluated exergoeconomically. In this regard, the system considered here is a GSHP heating system with a 50 m vertical U-bend ground heat exchanger having a 32 mm nominal diameter. This system was designed and installed at the Solar Energy Institute, Ege University, Izmir, Turkey.

Personalized ventilation (PV) has the ability to improve inhaled air quality and accommodate the individual thermal preference. In this paper one kind of personalized ventilation system which supplies fresh air at the microphone position is investigated numerically. A numerical thermal manikin with the real geometry of human body is used to study the airflows around the occupant equipped with PV. The performance of one RNG k-ε model and the standard k-ε model is compared.

A comprehensive modeling of radiative and convective heat transfer of a compact double-skin facade equipped with venetian blind is proposed here. Results from detailed CFD model were used in order to compute convective heat transfer coefficients and the radiation heat transfer, parts of energy balances of the proposed nodal model. The convective heat transfer coefficients found were weak and only little influenced by slat tilt angles and solar radiation.

Despite the low energy and lower maintenance benefits of ground-source heat pump systems, little work has been undertaken in detailed analysis and simulation of such systems. Long-term transient ground heat transfer significantly affects the performance of these systems. Annual and multi-year simulation consequently becomes an invaluable tool in the design of such systems – both in terms of calculating annual building loads and long-term ground thermal response. Models of vertical ground loop heat exchanges and water-to-water heat pumps have been implemented in the EnergyPlus program.

The paper describes a research project which addresses the problem of supervisory control of systems which include a range of heat sources combined with active and passive thermal storage. The work is based around a prototype building which has a ventilated PV array, solar air and water heating, biomass-fired boiler and a stratified thermal store. The supervisory control problem is, for each source, whether to deploy the energy directly into the building, store for later use or to reject to the environment.

We analyzed the thermal environment within Kyoto city using a numerical model that considers three elements: the unsteady-state heat conduction of building walls and ground surfaces, radiation heat exchange between walls and ground surfaces, and airflow approximated by computational fluid dynamics (CFD). We found that the model accurately simulates the thermal environment accurately within wide urban canyons. However, the various canyon shapes within a city each have unique of thermal characteristics.