Building envelope, duct leakage and HVAC system performance in HUD-code manufactured homes

Between 200,000 to 300,000 manufactured homes are built to the US Department of Housing and Urban Development’s Manufactured Home Construction and Safety Standards (MHCSS) in the US each year. This paper compares building envelope, duct leakage and HVAC s

Accurate performance testing of residential heat recovery units

The Norwegian Building Research Institute (NBI) has completed a study of the performance of balanced residential ventilation systems with heat recovery (HRVs) in Norway. The study involved both a national questionnaire survey and thorough laboratory tests of 10 HRVs on the market. The overall conclusion is that balanced ventilation with heat recovery provides very good air quality, and has a payback time of 4~6 years for the most profitable systems despite Norways cheap hydropower (0.09 /kWh in 2002).

A first study of natural and hybrid ventilation systems in the urban environment

An experimental campaign was organized during the summer period 2002 in Athens, in the framework of the European RESHYVENT Project. The main purpose was to indicate the impact of the urban environment on the natural and hybrid ventilation air flow process in urban canyons. Field and indoor experimental procedures were carried out in two urban canyons, presenting different geometric and urban features. The experiments were organized for more than three consecutive days within three different periods in summer and on a 24-hour basis.

Total energy performance of the air conditioning system using outdoor air cooling potential

From the view point of designing the energy efficient air conditioning system with maximized ventilation, the possibility of an all fresh air system was discussed using the simulation results of a model building in Tokyo. The algorithm of single duct cooling system for simulating the cooling coil of air handling unit based on the heat balance model of whole system components is also described as a base for the simulation of cooling effect of ventilation fresh air.

Ventilation calculation by network model inducing bi-directional flows in openings

For the multi-room ventilation calculations, bi-directional flows or counter flows in openings have been rarely taken into consideration and only uni-directional flows have been allowed for the calculation. It stands to reason that the calculation requires quite sophisticated scheme and the appearance of the bi-directional flows are restricted only to a limited number of openings neighboring the neutral plane of the building and also the flow rates may be too little to affect the total building

Use of simulation in the design of a large naturally ventilated commercial office building

The design for the new Federal Building for San Francisco includes an office tower that is to be naturally ventilated. The EnergyPlus thermal simulation program was used to evaluate different ventilation strategies for space cooling and rationalize the design of the faade. The strategies include ventilation driven by different combinations of wind, internal stack and external stack. The simulation results indicate that wind-drive ventilation can maintain adequate comfort even during hot periods.

Time varying linear model approximation : application to thermal and airflow building simulation

Considering the natural ventilation, the thermal behavior of buildings can be described by a linear time varying model. In this paper, we describe an implementation of model reduction of linear time varying systems. We show the consequences of the model reduction on computing time and accuracy. Finally, we compare experimental measures and simulation results using the initial model or the reduced model.

Numerical simulation of buildings thermal behaviour and human thermal comfort multi-node models

In this work two numerical models are presented. The first one simulates the buildings thermal response and evaluates the internal air quality, while the second one simulates the human and clothing thermal systems and calculates the thermal comfort level in non-uniform environments. The results obtained by the first model are used as input data in the second one.

Evaluation of a parametric model and building simulation for design of passive cooling by night ventilation

At the new institute building of Fraunhofer ISE, both mechanical and free night ventilation is used for passive cooling of the offices. The results from a monitoring of room temperatures in 21 office rooms during summer 2002 show that room temperatures exceeds 25 C in less than 8 % of the working hours, even at high ambient air temperatures. In two offices, experiments were carried out in order to determine the efficiency of night ventilation dependent on air change rate, solar and internal heat gains. During the experiments, meteorological data, air change rates, air temperatures (incl.

Modelling thermal comfort for tropics using fuzzy logic

Present international standard for thermal comfort such as ASHRAE Standard 55 and ISO 7730 were developed to serve as a guideline for moderate thermal environments e.g. mechanically airconditioned spaces [CEN ISO 1995]. Recent thermal comfort studies had reported that some discrepancies were observed in its application for Naturally Ventilated (NV) buildings in hot and

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