Search results for "ASHRAE 90.1"
showing 8 items of 8 documents
Energy and economic analysis of air-to-air heat pumps as an alternative to domestic gas boiler heating systems in the South of Italy
2019
Abstract According to the electricity tariff recently issued by the Italian government for the domestic heating systems fed with heat pumps (HP), an energy and economic analysis was carried out with the aim of investigating the effectiveness of the air-to-air heat pump systems (HPS) as an alternative to the traditional heating using domestic gas boilers systems (GBS). For the purpose of this study, the apartments of three residential buildings were examined. The hourly heating loads were calculated with the ASHRAE radiant time series and the coefficient of performance (COP) of the HPs was evaluated for each operating condition. The costs for the heating system installation and electricity a…
A clear sky atmospheric model valid for the mediterranean zone
1988
Abstract The ASHRAE clear sky model in the version proposed by G.L. Powell has been applied to a set of clear days from two coastal locations of Yugoslavia. The results have provided further elements to confirm the existence of a clear sky atmospheric model valid for the whole Mediterranean zone. This model is characterized by values of the atmospheric extinction coefficient higher than the corresponding ASHRAE ones with upper limits defined by the regression curve derived by using data of Palermo.
The ASHRAE clear sky model. An evaluation in the Mediterranean Zone
1988
Abstract The ASHRAE clear sky model in the version proposed by G. L. Powell is here applied to a yearly set of data for Palermo with small scale time intervals. The model is shown to yield computed values generally higher than the measured ones. New values for the atmospheric extinction coefficient are derived and proposed for the application to the Mediterranean atmosphere. A successful verification is performed using hourly data of Genoa, a location belonging to the same meteoclimatic area.
A Systematic Review of Air Quality Sensors, Guidelines, and Measurement Studies for Indoor Air Quality Management
2020
The existence of indoor air pollutants—such as ozone, carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen dioxide, particulate matter, and total volatile organic compounds—is evidently a critical issue for human health. Over the past decade, various international agencies have continually refined and updated the quantitative air quality guidelines and standards in order to meet the requirements for indoor air quality management. This paper first provides a systematic review of the existing air quality guidelines and standards implemented by different agencies, which include the Ambient Air Quality Standards (NAAQS); the World Health Organization (WHO); the Occupational Safety and Heal…
Is the transfer function method reliable in a European building context? A theoretical analysis and a case study in the South of Italy
2005
Abstract The available tools for dynamic simulation of the buildings thermal behaviour are manifold, and the most modern ones, known as TRNSYS, are founded upon the use of the Z-transform (ZT) set also called transfer function method (TFM). The transfer function method (TFM), recommended by American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), is one of the most modern tools available to solve heat transfer problems in building envelopes and environments. TFM utilises Z-transforms to solve the equation system that describes the heat transfer in a multi-layered wall. Due to an analogy with an electric circuit, it is possible to write the equation system in a mat…
Fifty Years of PMV Model: Reliability, Implementation and Design of Software for Its Calculation
2019
In most countries, PMV is the reference index for the assessment of thermal comfort conditions in mechanically conditioned environments. It is also the basis to settle input values of the operative temperature for heating and cooling load calculations, sizing of equipment, and energy calculations according to EN 16798-1 and 16798-2 Standards. Over the years, great effort has been spent to study the reliability of PMV, whereas few investigations were addressed to its calculation. To study this issue, the most significant apps devoted to its calculation have been compared with a reference software compliant with EN ISO 7730 and the well-known ASHRAE Thermal Comfort Tool. It has been revealed …
A criterion for the assessment of the reliability of ASHRAE conduction transfer function coefficients
2010
This paper presents a new mathematical approach, which, when applied to conduction transfer functions (CTFs) of a multi-layered wall, is able to predict the reliability of building simulations. This new procedure can be used to identify the best set of CTF coefficients, which are a critical point at the core of the ASHRAE calculation methodology founded on the transfer function method. To evaluate the performance of different CTF coefficient sets, the authors performed a large number of thermal simulations on the multi-layered walls included in the ASHRAE Handbook, volume fundamentals, and on other walls typical of Mediterranean building heritage. Those data were employed to test an algorit…
On the reliability of ASHRAE conduction transfer function coefficients of walls
2000
The transfer function method recommended by the ASHRAE can be considered the most modern tool currently available for the thermal analysis of a building. It is particularly well suited for use with a computer as it makes it possible to describe with great accuracy the internal heat gain of walls using a small set of coefficients. The present paper shows how to calculate sets of coefficients diverse from that proposed by Mitalas who first developed the method and on the basis of an unequivocal criterion, to prove the advantages in using them. The authors also investigated some of the paramount mathematical and physical aspects which affect the approximation degree of the ASHRAE method and, w…