There is research acknowledging that the home environment may be responsible for worsening respiratory conditions, especially for children. The indoor environment is a substantial source of exposure to pollutants e.g. environmental tobacco smoke. Apart from conducting specialised, costly and complex studies a method was needed to understand and assess indoor environments in the UK and how people could be encouraged to improve their indoor environment.
A manufactured home has been installed on the NIST campus for ventilation, energy andindoor air quality studies. The primary purposes of the facility are to study mechanicalventilation requirements for U.S. manufactured homes and to investigate the systems used tomeet these requirements. In addition, the building will be used to investigate moisture issues,indoor air quality impacts of combustion appliances, and VOC emissions from buildingmaterials and furnishings. The first phase of this multiyear effort has focused on airtightness,system airflows and air change rates.
To better quantify the impact of different window opening models in comparison to ventilation techniques a multizone ventilation model, incorporating the CO2-production of the inhabitants, was developed, using Comis-Transys. The reference model represents a free-standing dwelling in which infiltration is the only source of fresh air. Through a series of simulations natural ventilation systems (standard, user controlled or CO2-based demandcontrolled), air-tightness techniques and/or window opening models (deterministic or stochastic) are added.
The airflows through a one family prototype building have been simulated. Supply openings in living room and bedrooms have a size of 200 and 400 cm2 respectively. The ventilation system is a passive stack ventilation system, with ventilation chimneys from kitchen, WC and bathroom. The following parameters have been studied: the supply opening areas and heights, the overflow opening areas between bedrooms and hall and between WC/bathroom and hall, the height of the ventilation chimneys and the opening and closing of living room and bedroom doors.
The airtightness of a building envelope impacts upon the magnitude of uncontrolled air leakage and associated ventilation energy losses. A building's airtightness can be assessed using a steady state fan pressurisation technique. This paper describes a study on the largest building in the UK ever to have had its airtightness tested. Power law regression analysis revealed a good correlation between flow rate into the building and observed pressure differentials.
This paper presents the results of a field study conducted on 8 houses (out of a set of 31) owned and managed by a French social housing public leasing company. The central objective of our investigation was to evaluate and characterize the envelope leakage of these houses in order to propose and prioritize rehabilitation scenarios. For this, envelope leakage measurements were performed together with infrared thermography measurements.
The most efficient ventilation system would only operate on demand, when ventilation was "needed". Running the ventilation system all the time at a low flow rate, a rate sufficient to match the ASHRAE recommended 0.35 ACH is a crude control approach to an optimum system. Conditions in a house are not constant. On average, a constant flow rate ventilation system will work reasonably well and certainly is simple, but there are more energy efficient approaches, and users tend to shut down systems that run constantly.
Single- and double-section manufactured homes were instrumented in 2001-2003 to measure continuous energy usage and air infiltration with respect to the environmental conditions of a windy cold dry climate. The test site near Arlington, Wyoming, USA is ideal for testing the energy (and structural) performance of manufactured housing due to the naturally occurring high winds (in excess of 35 m/s annually) and temperature extremes (+35 to -35C). Tests included tracer gas monitoring, pressurized leakage tests, and infrared (IR) video scans.
In moderate climates, adventitious ventilation helps in keeping the water vapor balance in a building under control. This does not hold in hot and humid climates, where the outside air is a moisture source. Adventitious ventilation should be avoided in such climates and intended ventilation flows must be dried before entering the space. Anyhow, could adventitious ventilation also generate moisture problems in moderate climates? To get an answer, a reference case was analyzed with the air leakage distributed over facades and roof.
In France, most of the public project managers have collective dwellings built in the 70’s 80’s with first generation mechanical ventilation systems. These systems are not well perceived by the occupants who find them noisy, uncomfortable in winter and w