Submitted by Maria.Kapsalaki on Thu, 10/31/2013 - 22:50
This article is devoted to Indoor Air Quality (IAQ) in two low energy houses, with different frames (cast concrete (I-BB) and timber frame (I-OB)) built in platform INCAS of INES (National Institute of Solar Energy -in french: Institut National de l’Energie Solaire). In order to quantify pollutant emissions due to building materials and products, an experimental protocol consisted in stopping ventilation systems -”balanced ventilation”- of each house (a little before and during the measurement campaign), closing doors and windows, and not allowing occupant.
Submitted by Maria.Kapsalaki on Thu, 10/31/2013 - 15:34
Recently, buildings with thermal energy storage system have increased because of its economic advantage. In thermal energy storage system using introduced outdoor air, building masses are used as thermal storage media and cooled by outdoor air introduced by a mechanical fan in night-time. In spring and autumn, the cooled building masses can work to reduce cooling load in day-time. In this study, the stored heat was calculated by using simple heat transfer models for various building masses, and the energy performance of this system was evaluated quantitatively by system simulation.
To accurately estimate the natural ventilation of outdoor spaces surrounded by low-rise buildings using a wind tunnel requires correct representation of the natural wind regime combined with appropriately scaled building models and testing method. Existing outdoor ventilation studies are largely based on wind speed and estimated air change rates. Wind speeds mainly influence: peoples comfort, safety in pedestrian areas, the heat transfer between outdoor surfaces and airflow, and evaporation from wet surfaces.
That study was conducted in Nashville (TN) : during six weeks, measurements using passive ozone samplers were made on a group of school children aged 10 to 12 to estimate the outdoor/indoor /personal ozone exposure. Personal ozone exposure depends of the time spent indoors and outdoors.
An energy balance over an urban area and over a rural one, reveals that the first case is always more complex than the last one. The urban context is able to change all the energy transferences mainly due to its own layout. Thus, analysing all the energy transferences one by one, we can find how they affect in a different way depending on the surroundings, among other influences.
Within the framework of the French national research program PRIMEQUAL, measurementsof outdoor and indoor pollution have been carried out in eight schools of La Rochelle (France)and its suburbs. The buildings were naturally ventilated by opening the windows ormechanically ventilated, and showed various air permeabilities. Ozone, nitrogen oxides (NOand NO2), and particles (15 size intervals ranging from 0.3 to 15 m) concentrations werecontinuously monitored indoors and outdoors for two 2-week periods.
The relationship between indoor and outdoor concentration levels of particles in the absenceand in the presence of indoor sources has been attracting an increasing level of attention.Understanding of the relationship and the mechanisms driving it, as well as the ability toquantify it, are of importance for assessment of source contribution, assessment of humanexposure and for control and management of particles.
The concentrations of ultra fine particles (UFPs) were measured in the medium-size city ofGothenburg, Sweden, in the large city of Copenhagen and at a rural site in Denmark. InGothenburg, field measurements were conducted both in several residential and officebuildings, while in Denmark measurements comprise two office buildings, one of themlocated at a rural site. Concentrations of UFPs were measured simultaneously indoors andoutdoors.
Natural ventilation and infiltration are used for pollutant dilution and providing ‘fresh’ outdoor air supply in many buildings, in particular in residential buildings. Questions are often asked when natural ventilation should be encouraged. A balance-poi
This paper examines thermal mixing of outdoor and return airstreams in typical air-handling units equipped with parallel blade dampers. The mixing of the two airstreams in rectangular and square mixing chambers is studied for eight different dampers and blade orientations. Testing is conducted at a total supply air of 16000 CFM with outdoor flow percentages of 15% and 30%. The temperature differential between the outdoor and return airflows is kept at 40F. Damper blades with chords of 4 and 6 inches are tested.