Mechanical systems are used in buildings to provide conditioned air, dissipate thermal loads, dilute contaminants, and maintain pressure differences. The characteristics of these systems and their operations h implications for the exposures of workers to environmental tobacco smoke (ETS) and for the control of these exposures. This review describes the general features of building ventilation s...

A heat-recovery ventilator (HRV) effectively conducts ventilation by recovering waste heat from indoors to outdoors during heating periods. However, dew condensation associated with the HRV system may arise due to the difference between the indoor temperature and the very low outdoor temperature in winter, and this can decrease the heat exchange efficiency. These problems can be solved by the p...

In laboratory experiments, we investigated the ability of two task/ambient conditioning systems with air supplied from desk-mounted air outlets to efficiently ventilate the breathing zone of heated manikins seated at desks. In most experiments, the task conditioning systems provided 100% outside air while a conventional ventilation system provided additional space cooling but no outside air. Ai...

This paper proposes the analysis of real monitored data for evaluating relationship between occupants’ comfort conditions and energy balance inside an existing, nearly zero-energy building under different operational strategies heating, ventilation, air-conditioning system. During wintertime, adaptive approach is applied choosing temperature setpoint when air-to-air heat pump provides both heat...

Radon mitigation by natural basement ventilation was compared to mitigation by forced ventilation (pressurization) and to mitigation by the operation of a modified heating and air conditioning (HAC) system in a series of experiments conducted during the spring and summer in a research house. Both natural ventilation and basement pressurization reduced average basement radon concentrations from ...

The world is looking towards producing products which consume less power without compromising on quality of life. The increase in use of refrigeration and air conditioning appliances are contributing to global warming. The world wide temperatures are shooting up at an increasing rate. This paper presents a design of roll bond evaporator as the heat exchanger to provide cooling in room air condi...

Heat transfer from the internal surfaces of a vertical pipe to the adjacent air gives rise to the air flow establishment within the pipe. With the aim of optimizing the convective air flow rate in a vertical pipe, the details of the flow and thermal fields were investigated in the present study. Conservation equations of mass, momentum, and energy were solved numerically using simple implicit f...