Indoor air quality and energy issues of refrigerant modulating air-conditioning systems in the tropics

Due to its simplicity in installation and maintenance on the one hand, and to its potential to conserve energy on the other hand, the refrigerant modulating air-conditioning system has become very popular. This paper presents the results of an IAQ energy audit of two buildings in Singapore that use that kind of system. The results are compared to those obtained from conventional air-conditioning systems.

Classification for the room air conditioning strategies

This paper introduces a new strategy approach for the room air conditioning including classification and terminology. The aim of the classification is not to value one strategy over another (piston, stratification, zoning and mixing strategies are presented with their advantages and drawbacks, design criteria and applications) , it is up to the designer to select the most desirable strategy for each case. A clear classification of the ideal strategies will help the evaluation of the present room air distribution methods in different operating conditions.

Scale model study of airflow performance in a ceiling slot-ventilated enclosure : isothermal condition

The experimental investigation of airflow performance in a ceiling slot-ventilated enclosure under an isothermal condition was the aim of that study. Air-flow characteristics have been analyzed via experimental data then compared to literature theoretical expressions.
The results will be used in design guidelines of ventilation system for controlling indoor environment.

Integration of airflow and energy simulation using CONTAM and TRNSYS

The impact of infiltration and ventilation flows on energy use in commercial buildings has received limited attention. One of the reasons for this lack of study is that the commonly used programs for estimating the energy use of buildings do not incorporate the interzonal airflow modeling techniques
required to adequately account for the effect of these factors on energy usage. To address this issue and provide insight into the impact of these flows, the CONTAM airflow modeling tool

Performance test results for large coupled indoor/outdoor environmental simulator (C-I/O-ES)

This paper provides a summary of the methods and results of performance testing for a coupled Indoor/Outdoor Environmental Simulator (C-I/O-ES). The simulator consists of an IEQ chamber, a climate chamber, and a replaceable separation/test wall assembly. Both chambers have stainless steel interior surfaces and are equipped with independent heating, ventilating, and air-conditioning (HVAC) systems for simulating indoor and outdoor thermal and air quality conditions, respectively.

Stabilization of supply air temperature by using granulated phase change materials and application to ventilation system of a house during summer

The authors have proposed a system for stabilizing air temperature using direct heat exchange between granulated phase change materials (PCM) and air. This paper describes experiments in which air whose temperature is periodically changed to simulate changes of outdoor air temperature is passed through a bed of granulated PCM. These experiments demonstrate that output air temperature is stabilized and remains within the phase change temperature range. Results calculated by a computer simulation program described in a previous paper duplicate the experimental results.

Intercomparaison test of ventilation heat recovery units in houses

The CEN TC 156 / WG2 (ventilation for residential buildings) has prepared a new European draft for the test method of Heat Recovery Units (prEN 13141-7). This method should ensure a common way of testing these units all over Europe. In order to determine if the draft procedure is sufficient enough, both VTT and CETIAT has proceeded to some tests according to the new European standard on the same unit. Results on this first intercomparison give interesting data on the test method applied.

Office cooling with air or with chilled beams from an energy perspective

Even in cold climates, offices normally need to be cooled due to the internal heat loads from people, equipment and lighting. Either a chilled ceiling or chilled beams with cooled water as medium or chilled air can be used. In the case with chilled ceiling or chilled beams, a constant air volume system (CAV) is used. In the case of air only, a variable air volume (VAV) system must be used. This paper presents the advantages of the two methods of cooling with respect to energy use, which was calculated from climate data.

Case study of a floor-integrated solution for heating and ventilation in a pre-cast concrete domestic building

The paper describes a system solution developed in Sweden for domestic buildings with pre-cast concrete units where the floor consists of a 0,06 meter thick concrete slab with a framework casted into the slab and a beam. The beams acts as floor beams forming a cavity of about 0,3 meter that are used for plumbing, electric installations and transport of air for heating and ventilation. The air is blown from the cavity into the rooms through narrow slots along the walls. Air for heating is recirculated through a ventilation plant consisting of filter, heating element and a fan.

Evaluation of ventilation by stack effect using condensing units of refrigeration

Every city or town has a market to supply fresh food to its residents. A market has the function of displaying fresh food, auctioning it, and supplying it to consumers. A market must fulfill this role throughout the year even in cold, snowy areas, and this calls for a large, covered space. At the same time, vehicles of various sizes drive in and out of the market premises to transport food into and out of the market. These vehicles emit exhaust gas, however, and the introduction of a large amount of fresh air into the market space is indispensable for maintaining good air quality.

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