Showing papers in "Ashrae Journal in 1989"

Ventilation for acceptable indoor air quality

Abstract: About the author John E. Janssen, Member ASHRAE, has served as chairman of SPC 62-1981R since 1983 when an early review of Standard 62-1981 was started. He also served as vice chairman of SPC 62-73R, the committee that produced Standard 621981. Janssen retired from Honeywell after 35 years during which he conducted research on controls for ventilation, temperature control, flowmeters and thermal radiation properties.

Central solar heating plants with seasonal storage

Abstract: Every year, the United States uses approximately 15 quads of energy (26 quads of primary fuels) to heat buildings and water for domestic use. Applying solar energy to these loads is attractive because of the low-temperature requirements of the end-uses. However, past solar approaches to space heating in cold winter climates have not fared well technically or economically because the winter resource in northern climates is not adequate and is highly intermittent. This paper discusses a new approach, Central Solar Heating Plant with Seasonal Storage (CSHPSS), which allows for efficient solar collection throughout the year. With CSHPSS, a thermal storage facility can be charged so that a sufficient heat source is prepared to meet nearly 100% of the winter space heating and annual hot water loads. Recent developments in northern Europe have shown that, when implemented on a large scale, CSHPSS is very efficient and can provide cost competitive and reliable energy. In the United States, the first CSHPSS project is in a final engineering phase.

The new comfort equation for indoor air quality

Abstract: A new philosophy of ventilation is introduced. The philosophy is quantified in a new comfort equation for indoor air quality based on the new units olf and decipol. The comfort equation prescribes the ventilation required to obtain a desired perceived air quality (in decipol) and in space with a given pollution load (in olfs). The comfort equation acknowledges for the first time all pollution sources, not just human bioeffluents and smoking, and it quantifies for the first time the quality of indoor and outdoor air as perceived by human beings. The equation prescribes more ventilation than present standards, or a reduction of the hidden olfs ruining the ir quality in many existing buildings. The comfort equation establishes a rational basis for future ventilation standards.

Application of radiant heating saves energy

Abstract: Application of radiant principles is one of the best kept secrets of the 20th century. The purpose of this application can reduce energy requirements. The theory of energy release from a high temperature surface was first proposed as a commercial product in the early 1900s. This article provides an understanding of how transfer or radiant energy works, identifies the factors that contribute to its economical performance and demonstrates how applications of radiant heating can provide comfort with lower energy costs.

Analysis of flow in small, multi-zone HVAC systems

Abstract: Presentation d'un programme capable de prevoir l'influence de differentes positions des amortisseurs sur l'ecoulement d'air dans les reseaux de conduites de systemes de climatisation multizone. Verification du modele par des mesures sur le site. Possibilite d'utilisation du programme pour la conception des reseaux et le calcul des performances du systeme

Expert systems in preventive maintenance and diagnostics

Abstract: Analyse de l'utilisation d'un systeme expert pour la maintenance d'installations de climatisation, chauffage ou refrigeration et des fonctions necessaires a cette application. Exemple d'utilisation d'un systeme expert lors d'une visite de maintenance

The control of radiant slabs

Abstract: Recent analyses and simulations indicate that the current approach to controlling radiant slab heating systems is incorrect. There is some urgency in settling this control question since radiant slab systems are enjoying a strong resurgence in North America. Such systems may, by now, dominate residential and light commercial construction in northern Europe and Korea. The present installation practice is to embed 3/4 or 1/2 in. (13 or 19 mm) polybutylene or cross-linked polyethylene tubing within a 4 in. (101.6 mm) concrete slab laid on grade. A heat source, expansion tank, circulator and controls complete the system. The resulting system is simple, inexpensive and enjoys superior comfort, low first costs, low maintenance, quite, low-power delivery and compatibility with cogeneration or passive solar design. Because of the large delivery area, the radiant slabs operate at only a few degrees above set point, and thus, form an excellent delivery system for the ground-coupled heat pump.

Cooling tower corrosion

Abstract: If cooling towers are quickly deteriorating, it is most likely due to a corrosive atmosphere created by one of the herein mentioned problems. Cooling tower life can be prolonged, and even extended, many years by reviewing the following steps: (1) Investigate the areas for the cause of corrosion. (2) Take steps to eliminate or minimize the culprit. (3) Investigate the use of coatings for the interior. Use a qualified person to apply the coatings. (Usually the metal has to be ground down to a white metal finish before applying the coating.) (4) Review any new cooling tower locations for possible elements that could create corrosive conditions for the tower

Performance of micro-fin tubes with refrigerant-22 and oil mixtures

Abstract: Compressor lubricating oil is mixed with the refrigerant circulating in a vapor compression refrigeration system. Information on the heat transfer and pressure drop effects of oil is needed to design better heat transfer components. Furthermore, energy and heat exchanger size considerations are leading to an increasing use of tubes having enhanced heat transfer surfaces. Thus, data on the performance of these tubes are becoming more important. To address these two related issues, ASHRAE Technical Committee 1.3 sponsored research project 469-RP. This article highlights the results of 469-RP. The research project was divided into three phases; review of the literature, experimental investigation, and development of correlation expressions. The results of the experimental investigation are emphasized in this article.

Refrigerant mixtures ― challenges and opportunities

Abstract: Presentation des proprietes du refrigerant ideal. Expose des proprietes thermodynamiques et de transport des melanges de refrigerants comme des proprietes de ces melanges melanges avec des huiles de lubrification de compresseur. Presentation des imperatifs de maintenance lies a l'utilisation de melanges de refrigerants

Advanced heat pumps for the 1990s

Abstract: Presentation des caracteristiques des pompes a chaleur ameliorees. Exploration des perspectives de rendement energetique et gestion de puissance pour ces pompes a chaleur du point de vue de l'utilisateur et du distributeur d'electricite. Presentation du programme de dimensionnement de pompe a chaleur ameliore. Comparaison des coefficients de performance et des couts d'exploitation de pompes a chaleur amelioree et conventionnelle dans cinq villes americaines

The myth of pressure-independent VAV terminals

Abstract: Presentation point par point des «mythes» concernant les systemes de ventilation a air variable: dimensionnement d'un systeme VAV pour de faibles pertes de charge, reduction du niveau de bruit, regulation PI necessaire pour les systemes avec rechauffage, sur dimensionnement

Computerizing refrigeration load calculations

Abstract: Presentation des programmes de calcul de charges de refrigeration, utilisables sur microordinateurs et pour la conception d'une installation frigorifique, en les comparant a ceux employes pour le dimensionnement d'installations de chauffage ou de climatisation. Description des avantages des programmes, des criteres de selection du programme et du materiel

Central vs. local HVAC for systems for highrise office buildings

Abstract: Comparaison de deux types de conditionnement d'air: l'un dont les ventilateurs sont centralises, l'autre desservi par des ventilateurs locaux sur le plan du cout de construction, du cout d'exploitation, de consommation d'energie, de la qualite de l'air, de regulation, etc.

Research and development focus on commercial natural gas cooling/air conditioning

Abstract: Absorption-cycle refrigeration has been, and remains, the dominant technology of gas-fueled cooling equipment. Historically in commercial comfort-system applications, steam generated from gas or other fuels was the medium supplied to absorption-based liquid chillers. However, the popularity of this equipment has decreased in favor of electric equipment over the last several decades, due in part to gas supply curtailments and technical advances in electrical equipment. Concurrent with the decline of new absorption equipment sales was that of engine-powered chillers offered by industrial engine packagers and HVAC manufacturers. Although this engine-based equipment never achieved the sales volume of absorption, the late '60s brought the decline of sales volumes and, by the mid-'70s, the near-complete disappearance of this cooling equipment option. A new variation of absorption equipment emerged in the HVAC market in the early '80s. This equipment is directly fueled and combines the functions of a boiler and chiller, including the capability of simultaneous chilled water and heated water production. The direct-fired cooling equipment exploits a double-effect absorption process, resulting in superior fuel utilization and cold production efficiency.

Technical tour of the Georgia Power corporate headquarters building

Abstract: Description d'un systeme de refroidissement d'un immeuble alliant un stockage d'eau glacee, un systeme actif solaire chauffant l'eau utilisee dans le groupe d'absorption et un systeme passif (conception du bâtiment). Cette installation permet une utilisation rationnelle de l'energie et une facture energetique amoindrie

The scientific basis of standard 62-1989

Abstract: Le standard 62-1989 est un etalon precisant le taux de ventilation minimum et la qualite de l'air interieur acceptable pour les occupants humains et permettant de reduire les effets nefastes des polluants sur la sante

A knowledge-based system for confort diagnostics

Abstract: Description du fonctionnement et de la conception d'un systeme expert applique au genie climatique a partir d'un exemple: diagnostic des causes d'inconfort dans un immeuble climatise