In order to facilitate nationwide analysis of ventilation and indoor air quality issues in residential buildings, a set of homes has been defined to represent the housing stock of the United States. This so-called 'suite of homes' is based on two residential housing surveys, the U.S. Department of Energy Residential Energy Consumptions Survey (RECS) and the U.S. Census Bureau American Housing Survey (AHS). The RECS dataset includes about 6000 U.S. residences and the AHS covers about 60000, and are both intended to periodically characterize the U.S. housing stock.
Twenty homes were tested and monitored in Houston, Texas, U.S.A. to evaluate humidity controlperformance and operating cost of six different integrated dehumidification and ventilation systems that could be applied by production homebuilders. Fourteen houses had one of the six integrated dehumidification and ventilation systems and also met a high standard of energy efficiency criteria.
Passive cooling strategies require strict adherence to the physical world. Ones imagination creates the flow of ideas that can blossom into a comfortable setting, but the reality of design, construction and cooperation has to be observed and accepted. Physical laws govern as natural processes follow the path of least resistance. In order for us to overcome these laws extra energy is required. That is why passive cooling designers must investigate how to create a comfortable setting by understanding how natural procedures work.
The thermal performance of a monozone building located in Lisbon is studied when night ventilation combined with radiative cooling is used in order to remove the heat from indoors. For simulating the thermal behaviour of the building, a commercial energy building software is used. The potential for radiative cooling in Lisbon, as well as the efficiency of the radiative cooling system were investigated previously. A validated numerical model is used in order to predict the temperature of the air at the outlet of the radiative system.
Cavity wall is often proposed in the building envelope design as a solution for improving the thermal comfort of the inhabitants and reducing the adverse condensation effects on the building fabric. In order to evaluate the thermal effect of ventilated air gaps on building energy demand and comfort, an experimental ventilated cavity wall has been built and tested. The cavity wall separates two ambients at different temperatures that are assumed to be constant over the time required to perform the experimental analysis.
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.