The thermal behavior of large supermarkets is dominated by internal gains. Specifically, refrigerated and frozen food display units area is characterized by cool loads created by commercial cases, which are also moisture trap. A coupling approach of air conditioning with display cases operation is proposed in this paper, based on a model of the cold aisle phenomenon. In this area, the significant vertical stratification of air has to be considered to calculate electric consumption of display cases. Heat and moisture exchanges are calculated and typical values are given.
During the last ten years, many HVAC simulation models and calculation tools were developed. However, until now, the practical use of simulation tools is still very limited in building and HVAC design as well as in the development of control strategies. This paper focuses on the selection and sizing of a centralized cooling plant. Its purpose is to show how the simulation can help the designer and to point out the difficulties encountered by the simulation user. In the design stage, various alternative cooling systems are available.
Most of the dynamic models of hot water boilers are either "reference" models or too simplified ones. The formers require sophisticated computation facilities (they are CPU - time consumers) and very detailed data on boiler geometry which are usually not available. The latters are generally identified models based on experimental tests, thus their range of validity is limited to the domain covered by the experimental data. This paper presents a simplified second order dynamic model which uses available manufacturer data.
A new concept of combustion control system, based on an optical information from the flame spectrum, is applied to a domestic fuel oil boiler. The objective is to achieve the maximum thermal efficiency of the boiler, while keeping a stable flame and the pollutant emissions as low as possible. CH radicals and soot continuum emissions, measured with a spectrometer just downstream of the burner exit, provide the information needed.
This study presents the method, procedure and partial results of commissioning of air conditioning system. The work was carried out with Justus Lispsius building of the Ministry Council of the European Union in Brussels. The objective of the commissioning is to check the hydraulic characteristics of air distribution system and the thermal performance of air handling units, use the simulation method to predict the cooling demand, improve the performance of air-conditioning system, eventually minimise the energy consumption.
Fan coil units are widely used to realise a thermally comfortable indoor climate in rooms. The main components are the heating coil, the control valve and the fan. Hot water flows through the heating coil and heats the passing room air. In case cooling is required also a cooling coil is installed. This paper presents a new control system. This control system uses inexpensive open/closed valves for precise control of heat, released by the fan coil unit. It uses two cascade control loops to adjust the indoor temperature. The main control loop controls the indoor air temperature.
The window coverage of buildings has increased in the past five years. This is especially true for office buildings. The national guidelines (ISO, DIN, CEN) advise designing according to the operative temperature. Following the advice leads to higher operative temperature than inside temperature in buildings with greater window coverage. We made local measurements in an office building. We determined air temperature operative temperature, subjective thermal votes, PMV, and PPD. Our paper contains the results of these measurements and conclusions.
Noise is the most common cause of complaint to environmental health officers in England and impact noise through ceilings has been identified as being particularly disturbing to occupants of dwellings. Floating floors incorporating a resilient layer are an accepted method of reducing impact noise and traditionally rockwool or mineral fibre quilts have been used. Flexible polyurethane open cell foams are now used in some systems in thinner layers than mineral fibre quilts and are more pleasant to handle.
This paper discusses the data handling and analysis software that has been produced as part of the Texas LoanSTAR program, a $98.6 million revolving loan program for funding energy conservation projects in state agencies. In this paper an overview of the different facets of data management for monitoring building energy data is presented.
This paper describes an improved multipyranometer array (MPA) for the continuous measurement of direct and diffuse solar radiation. The MPA described in this paper is an improvement over previously published MPA studies due several new features, including: the incorporation of an artificial horizon that prevents reflected ground radiation from striking the tilted sensors, and a routine that corrects the spectral response of photovoltaic-type sensors used in the MPA.