Numerical analysis of thermal comfort in Near-Zero Energy Buildings (NZEB) with light radiant ceilings and diffuse ventilation

Renewable energy sources for heating and cooling buildings usually have temperatures close to room temperature and therefore a limited convertibility potential, i.e. they are of low value. To exploit low-valued energy sources Low Temperature Heating and High Temperature Cooling (LTH-HTC) systems must be developed.

A Novel Method for Thermostat Set Point Prediction for Energy Savings and/or Better Human Thermal Comfort - A Zonal Modelling Approach

Very often the set point temperature is selected to satisfy comfort requirements and/or to save energy consumption in buildings. However, the thermostat location is usually outside the occupied space and located on the wall near a front door or in a hallway that is subject to warm and cold draughts. A discrepancy exists between the temperature at the thermostat location and the occupied zones.

CFD simulation of an office heated by a ceiling mounted diffuser

The paper investigates the possibility for using a traditional ventilation system with ceiling mounted diffusers to provide heating under winter time conditions in relatively cold climates – in buildings with low transmition losses such as “passive houses”. The analysis is done through a number of CFD simulations of a simplified office. It is shown that even small over-temperatures reduce the Air Change Efficiency substantially. On the other hand even very small internal heat sources increase the efficiency.

Heating "passive house" offices in cold climate using only the ventilation system – comparison of two ventilation strategies

In this article we compare to ventilation strategies to heat a “passive house” office building using only the ventilation system. Two ventilation strategies with supply air temperature above and below the current room temperature were compared through a cross over experiment. A questionnaire was used to measure the perceived health and well being. Both strategies documented very good indoor climate with highly positive scores on the questionnaire.

Designing for performance: a case study in the applied science of an environmentally responsive high-rise design

This paper explores the developing process and resulting features of an ultra high performance tower designed by Skidmore, Owings and Merrill through a multidisciplinary approach to building simulation and analysis. The 309 meter tall office tower for a new development in the Pearl River Delta region of Southern China, is an exemplar of the marriage of technical sophistication with a graceful form, featuring integrated renewable energy strategies and an active double skin facade coupled with a low energy building conditioning system.

Application of modeling and simulation in fault detection and diagnosis of HVAC systems

Failures can lead to a series of problems in the complex heating, ventilation and air-conditioning (HVAC) systems in buildings. Fault detection and diagnosis (FDD) is an important technology to solve these problems. Models can represent the behaviors of the HVAC systems, and FDD can be realized with models. Using the model as intermediary, a link between system simulation and FDD can be built. Simulation has provided a convenient platform of operation for FDD, the overall simulation methodology in FDD of HVAC systems is briefly introduced.

Influence of solar radiation data processing on building simulation results

A new set of climatic data for different kinds of calculations has been compiled for various Swiss localities. This includes the generation of new design reference year data sets with hourly values for e.g. building simulations. The procedure conforms to a set of new European standards describing the algorithms. One key element in this is the processing of solar radiation information, especially for the separation into direct and diffuse components. The most advanced methodology was used.

Hydronic radiant floor for heating and cooling coupled with an underground heat exchanger: Modeling approach and results

This paper explores the simulation of the thermal performance of a radiant floor for heating and cooling that is connected with an underground heat exchanger installed under the concrete floor of a house. In the heating season, an electric boiler is used to maintain the operative temperature at the set point value by varying the supply water temperature to the radiant slab. In the cooling season, the water from the radiant floor is circulated through an underground heat exchanger installed under the concrete slab.

EXERGY CONCEPT AND ITS APPLICATION TO THE BUILT ENVIRONMENT

This paper first introduces the concept of “exergy”, which quantifies what is consumed by any working systems from man-made systems such as heat engines to biological systems including human body. “Exergy” balance equation for a system can be derived by c

Increased Energy Efficiency and Improved Comfort

This paper summarises the work of the LowEx co-operation /1/. The aim was to promote rational use ofenergy by encouraging the use of low temperature heating systems and high temperature cooling systems ofbuildings. These systems can use a variety of fuels and renewable energy sources. Energy is used efficientlywhile providing a comfortable indoor climate. Exergy defines the quality of energy and is a concept fordesigning and assessing different heating and cooling systems. Application of exergy analysis into buildingshas not been common before.

Pages