measurement

The airflow rate in heating and cooling equipment has major implications for the performance of the system. Improper flow across air conditioner and heat pump coils degrades the capacity of the coil, low flow across the heat exchanger in furnaces can cause the system to cycle on the high-temperature limit switch, and the flow rate has major implications for the efficiency of the duct system. The primary method for measuring the airflow through an air handler uses the change in temperature between the return and supply side of the air handler.

Leakage data for ducted air terminal connections are reported. The leakage flow rate generally varied from 1% to 8% of the total approach flow rate. Leakage was found to increase with the increase in the static pressure adjacent to the terminal for the unsealed condition. With marginal sealing of rigid ducts, leakage was found to be less than half that of the unsealed connection. The use of drawbands to mount air terminals to flexible ducts can reduce leakage at the collar to virtually

An experimental study was conducted to estimate the leakage through air terminal connections to rigid duct and flexible duct. Air terminals from three different manufacturers were tested under different sealing conditions, namely, unsealed, marginally sealed, and fully sealed. Diffusers and supply grilles were tested in a blow-through test setup, whereas return grilles were tested in a draw-through test setup. The experimental procedure and data reduction are described.

Residential distribution systems are inherently inefficient at delivering heated or cooled air to the conditioned space as the result of poor design and installation practices. Examples of some of the more common problems include heat loss/gain in unconditioned spaces and leakage through supply and return ducts. These defects can result in significantly increased energy consumption, poor thermal comfort, and high peak electricity demand. Efforts to improve distribution systems

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.

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.

For energy savings, DCV systems are more and more used on ventilation systems. In France, in non residential buildings, these systems are generally controlled by either a CO2 sensor, or an optical movement detection (infrared). To achieve correct performances, pressure conditions in duct and fan regulation must be considered.

The aim of this project has been to provide information on energy consumption in different building categories. Previous studies have focused on total energy use and not on how the consumption of energy is divided in various categories. On a national level, statistical data are generally available in terms like energy consumption per square meter.

An evaluation of different ventilation principles and their application in various premises like bars and restaurants has been conducted. Measurements of nicotine concentrations revealed a strong dependency on ventilation solutions. In restaurants and bars where the ventilation systems are properly designed it is possible to fulfill requirements issued by the Norwegian authorities.

We have investigated the effect of UVC on IAQ in a ventilation plant in a typical office building. The UVC-system consisted of UVC-lights for irradiation on all central components in the air handling unit. A similar ventilation plant, but without UVC, was chosen as a reference plant. Microorganisms on surfaces, living airborne mould spores and MVOC (Microbial Volatile Organic Compounds) were sampled throughout the ventilation plant and in corresponding rooms before and after UVC-irradiation. In addition, parallel measurements in the reference plant were conducted.