Ventilation is the intentional introduction of outdoor air into a space. Ventilation is mainly used to control indoor air quality by diluting and displacing indoor pollutants; it can also be used to control indoor temperature, humidity, and air motion to benefit thermal comfort, satisfaction with other aspects of the indoor environment, or other objectives.
Heat recovery ventilation (HRV), also known as mechanical ventilation heat recovery (MVHR) or energy recovery ventilation (ERV), is a ventilation system that recovers energy by operating between two air sources at different temperatures. It is used to reduce the heating and cooling demands of buildings.
Building science is the science and technology-driven collection of knowledge in order to provide better indoor environmental quality (IEQ), energy-efficient built environments, and occupant comfort and satisfaction. Building physics, architectural science, and applied physics are terms used for the knowledge domain that overlaps with building science. In building science, the methods used in natural and hard sciences are widely applied, which may include controlled and quasi-experiments, randomized control, physical measurements, remote sensing, and simulations. On the other hand, methods from social and soft sciences, such as case study, interviews & focus group, observational method, surveys, and experience sampling, are also widely used in building science to understand occupant satisfaction, comfort, and experiences by acquiring qualitative data. One of the recent trends in building science is a combination of the two different methods. For instance, it is widely known that occupants' thermal sensation and comfort may vary depending on their sex, age, emotion, experiences, etc. even in the same indoor environment. Despite the advancement in data extraction and collection technology in building science, objective measurements alone can hardly represent occupants' state of mind such as comfort and preference. Therefore, researchers are trying to measure both physical contexts and understand human responses to figure out complex interrelationships.
Displacement ventilation (DV) is a room air distribution strategy where conditioned outdoor air is supplied at a low velocity from air supply diffusers located near floor level and extracted above the occupied zone, usually at ceiling height.
Underfloor heating and cooling is a form of central heating and cooling that achieves indoor climate control for thermal comfort using hydronic or electrical heating elements embedded in a floor. Heating is achieved by conduction, radiation and convection. Use of underfloor heating dates back to the Neoglacial and Neolithic periods.
Building performance is an attribute of a building that expresses how well that building carries out its functions. It may also relate to the performance of the building construction process. Categories of building performance are quality, resource savings and workload capacity. The performance of a building depends on the response of the building to an external load or shock. Building performance plays an important role in architecture, building services engineering, building regulation, architectural engineering and construction management. Furthermore, improving building performance is important for addressing climate change, since buildings account for 30% of global energy consumption, resulting in 27% of global greenhouse gas emissions. Prominent building performance aspects are energy efficiency, occupant comfort, indoor air quality and daylighting.
Thermal comfort is the condition of mind that expresses subjective satisfaction with the thermal environment. The human body can be viewed as a heat engine where food is the input energy. The human body will release excess heat into the environment, so the body can continue to operate. The heat transfer is proportional to temperature difference. In cold environments, the body loses more heat to the environment and in hot environments the body does not release enough heat. Both the hot and cold scenarios lead to discomfort. Maintaining this standard of thermal comfort for occupants of buildings or other enclosures is one of the important goals of HVAC design engineers.
The Zero Power Physics Reactor or ZPPR was a split-table-type critical facility located at the Idaho National Laboratory, Idaho, USA. It was designed for the study of the physics of power breeder systems and was capable of simulating fast reactor core compositions characteristic of 300-500 MWe demonstration plants and 1000 MWe commercial plants.
A thermal bridge, also called a cold bridge, heat bridge, or thermal bypass, is an area or component of an object which has higher thermal conductivity than the surrounding materials, creating a path of least resistance for heat transfer. Thermal bridges result in an overall reduction in thermal resistance of the object. The term is frequently discussed in the context of a building's thermal envelope where thermal bridges result in heat transfer into or out of conditioned space.
An energy audit is an inspection survey and an analysis of energy flows for energy conservation in a building. It may include a process or system to reduce the amount of energy input into the system without negatively affecting the output. In commercial and industrial real estate, an energy audit is the first step in identifying opportunities to reduce energy expense and carbon footprint.
Underfloor air distribution (UFAD) is an air distribution strategy for providing ventilation and space conditioning in buildings as part of the design of a HVAC system. UFAD systems use an underfloor supply plenum located between the structural concrete slab and a raised floor system to supply conditioned air to supply outlets, located at or near floor level within the occupied space. Air returns from the room at ceiling level or the maximum allowable height above the occupied zone.
Ian Beausoleil-Morrison is a full professor of mechanical and aerospace engineering at Carleton University in Ottawa, Ontario and a past adjunct associate professor at both Dalhousie University and the University of Victoria. He holds a Bachelor's of Applied Science and a Master's of Applied Science from the University of Waterloo, and a Ph.D. from the University of Strathclyde, Scotland.
Radiant heating and cooling is a category of HVAC technologies that exchange heat by both convection and radiation with the environments they are designed to heat or cool. There are many subcategories of radiant heating and cooling, including: "radiant ceiling panels", "embedded surface systems", "thermally active building systems", and infrared heaters. According to some definitions, a technology is only included in this category if radiation comprises more than 50% of its heat exchange with the environment; therefore technologies such as radiators and chilled beams are usually not considered radiant heating or cooling. Within this category, it is practical to distinguish between high temperature radiant heating, and radiant heating or cooling with more moderate source temperatures. This article mainly addresses radiant heating and cooling with moderate source temperatures, used to heat or cool indoor environments. Moderate temperature radiant heating and cooling is usually composed of relatively large surfaces that are internally heated or cooled using hydronic or electrical sources. For high temperature indoor or outdoor radiant heating, see: Infrared heater. For snow melt applications see: Snowmelt system.
MOOSE is an object-oriented C++ finite element framework for the development of tightly coupled multiphysics solvers from Idaho National Laboratory. MOOSE makes use of the PETSc non-linear solver package and libmesh to provide the finite element discretization.
Goma is an open-source, parallel, and scalable multiphysics software package for modeling and simulation of real-life physical processes, with a basis in computational fluid dynamics for problems with evolving geometry. It solves problems in all branches of mechanics, including fluids, solids, and thermal analysis. Goma uses advanced numerical methods, focusing on the low-speed flow regime with coupled phenomena for manufacturing and performance applications. It also provides a flexible software development environment for specialty physics.
Building performance simulation (BPS) is the replication of aspects of building performance using a computer-based, mathematical model created on the basis of fundamental physical principles and sound engineering practice. The objective of building performance simulation is the quantification of aspects of building performance which are relevant to the design, construction, operation and control of buildings. Building performance simulation has various sub-domains; most prominent are thermal simulation, lighting simulation, acoustical simulation and air flow simulation. Most building performance simulation is based on the use of bespoke simulation software. Building performance simulation itself is a field within the wider realm of scientific computing.
OpenStudio is a suite of free and open-source software applications for building energy analysis used in building information modeling. OpenStudio applications run on Microsoft Windows, Macintosh, and Linux platforms. Its primary application is a plugin for proprietary SketchUp, that enables engineers to view and edit 3D models for EnergyPlus simulation software.
The International Energy Agency Energy in Buildings and Communities Programme, formerly known as the Energy in Buildings and Community Systems Programme (ECBCS), is one of the International Energy Agency's Technology Collaboration Programmes (TCPs). The Programme "carries out research and development activities toward near-zero energy and carbon emissions in the built environment".
IDA IndoorClimate andEnergy is a Building performance simulation (BPS) software. IDA ICE is a simulation application for the multi-zonal and dynamic study of indoor climate phenomena as well as energy use. The implemented models are state of the art, many studies show that simulation results and measured data compare well.
Ventilative cooling is the use of natural or mechanical ventilation to cool indoor spaces. The use of outside air reduces the cooling load and the energy consumption of these systems, while maintaining high quality indoor conditions; passive ventilative cooling may eliminate energy consumption. Ventilative cooling strategies are applied in a wide range of buildings and may even be critical to realize renovated or new high efficient buildings and zero-energy buildings (ZEBs). Ventilation is present in buildings mainly for air quality reasons. It can be used additionally to remove both excess heat gains, as well as increase the velocity of the air and thereby widen the thermal comfort range. Ventilative cooling is assessed by long-term evaluation indices. Ventilative cooling is dependent on the availability of appropriate external conditions and on the thermal physical characteristics of the building.
