HVAC

Open offices, where more than one person works, have been used frequently in recent years. However, there are many studies on the efficiency of the indoor air quality of the employees in these offices. It has also been shown that the risk of cross-contamination is higher in such offices during the COVID period, but this risk can be reduced by increasing the amount of fresh air.

HVAC systems in newly built or extensively renovated dwellings were all developed with the aim for energy saving with equal or better comfort. However, these systems (floor heating and DCV systems) have certain characteristics which increase the emissions of Volatile Organic Compounds (VOCs) and give VOCs the chance to accumulate to higher concentrations. This interaction is investigated based on dynamic simulations using a temperature and humidity dependent VOC emission model. 

Thermal comfort and sensation are important aspects of the building design and indoor climate control as modern man spends most of the day indoors. Conventional indoor climate design and control approaches are based on static thermal comfort/sensation models that views the building occupants as passive recipients of their thermal environment. Assuming that people have relatively constant range of biological comfort requirements, and that the indoor environmental variables should be controlled to conform to that constant range.

Experimental investigation of ceiling circular grille air jets was conducted in a full-scale entirely controlled test room (6.2 x 3.1 x 2.5 m). Our case study is based on a realistic ventilation system configuration: it introduces a plenum box, two air exhausts, as well as a vertical wall near the air inlet. Analyses were initially concentrated at the air inlet region since it is the zone having strong gradients. Deviations concerning the trajectory of the actual jet were observed with respect to the theoretical jet.

Night ventilation is used extensively as a low energy strategy to cool buildings in climates where night temperatures are suitable. It can be used for spaces utilising natural or mechanical ventilation systems as well as active refrigerant cooling. Most published work focuses on domestic and relatively simple in operation commercial buildings such as offices. This paper presents a study of the cooling benefits of night ventilation for frozen food supermarkets with high cooling demand.

INTRODUCTION: The Finnish Society of Indoor Air Quality and Climate (FiSIAQ) introduced over twenty years ago in 1995 a Classification of Indoor Climate, Construction Cleanliness, and Finishing Materials and the third edition will be published autumn in the year 2017. Based on the criteria set in the classifications, The Building Information Foundation RTS sr started the M1-labelling of air handling components in 1999. Name of the classification is Cleanliness Classification of Air Handling Components.

Supermarkets are a category of non-domestic buildings with high energy use because of their operation. Recent work indicates that by improvements to the energy delivery systems through which internal environmental conditions are maintained such as thermal properties of external envelope including airtightness, HVAC systems and lighting, substantial energy savings can be achieved. Work to date has focused on typical supermarkets while the present paper examines frozen food supermarkets which include more refrigeration cabinets and therefore result in higher energy use per sales floor area.

A specific type of centrifugal fan named the "squirrel-cage" is broadly used in parallel configurations within an evaporator unit of HVAC systems for public transport. In these units, interaction effects arise, both between fans themselves and between fans and the structural elements. Blockage effects, such as the electrical motor, the evaporator gate and some aesthetic covering may also appear when these external elements are located very close to the fans aspiration nozzles.

This application paper outlines some innovative building simulation methodologies used to predict thermal performance of complex energy efficient systems using commercially available softwares. Industry case studies are presented to demonstrate how simulation can influence the design process with requirements varying from zero carbon emissions to optimum thermal comfort. Simplifications used to reduce computational time and handle software limitations are assessed in regards to model accuracy and the ability to influence the design decision process.

Time of use (TOU) electricity metering involves dividing the day, the month and the year in to slots or bands, with generally higher rates at the peak loads and low tariff rates at off-peak load periods. For this study, the statistically representative testcase Canadian house was modeled in the building energy simulation software ESP-r to estimate its sub-hourly (every fifteen minutes) electricity consumption for the appliances, lighting, domestic hot water (DHW) and space heating for an entire year.