Condensation is the change of the state of matter from the gas phase into the liquid phase, and is the reverse of vaporization. The word most often refers to the water cycle. It can also be defined as the change in the state of water vapor to liquid water when in contact with a liquid or solid surface or cloud condensation nuclei within the atmosphere. When the transition happens from the gaseous phase into the solid phase directly, the change is called deposition.
Humidity is the concentration of water vapour present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present.
A dehumidifier is an air conditioning device which reduces and maintains the level of humidity in the air. This is done usually for health or comfort reasons, or to eliminate musty odor and to prevent the growth of mildew by extracting water from the air. It can be used for household, commercial, or industrial applications. Large dehumidifiers are used in commercial buildings such as indoor ice rinks and swimming pools, as well as manufacturing plants or storage warehouses.
Mildew is a form of fungus. It is distinguished from its closely related counterpart, mould, largely by its colour: moulds appear in shades of black, blue, red, and green, whereas mildew is white. It appears as a thin, superficial growth consisting of minute hyphae produced especially on living plants or organic matter such as wood, paper or leather. Both mould and mildew produce distinct offensive odours, and both have been identified as the cause of certain human ailments.
A basement or cellar is one or more floors of a building that are completely or partly below the ground floor. It generally is used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, car park, and air-conditioning system are located; so also are amenities such as the electrical system and cable television distribution point. In cities with high property prices, such as London, basements are often fitted out to a high standard and used as living space.
Water damage describes various possible losses caused by water intruding where it will enable attack of a material or system by destructive processes such as rotting of wood, mold growth, bacteria growth, rusting of steel, swelling of composite woods, de-laminating of materials such as plywood, etc.
Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments or underwater to specified depths.
An attic is a space found directly below the pitched roof of a house or other building; an attic may also be called a sky parlor or a garret. Because attics fill the space between the ceiling of the top floor of a building and the slanted roof, they are known for being awkwardly shaped spaces with exposed rafters and difficult-to-reach corners.
A vapor barrier is any material used for damp proofing, typically a plastic or foil sheet, that resists diffusion of moisture through the wall, floor, ceiling, or roof assemblies of buildings to prevent interstitial condensation and of packaging. Technically, many of these materials are only vapor retarders as they have varying degrees of permeability.
Superinsulation is an approach to building design, construction, and retrofitting that dramatically reduces heat loss by using much higher levels of insulation and airtightness than normal. Superinsulation is one of the ancestors of the passive house approach.
A building envelope is the physical separator between the conditioned and unconditioned environment of a building including the resistance to air, water, heat, light, and noise transfer.
A ground-coupled heat exchanger is an underground heat exchanger that can capture heat from and/or dissipate heat to the ground. They use the Earth's near constant subterranean temperature to warm or cool air or other fluids for residential, agricultural or industrial uses. If building air is blown through the heat exchanger for heat recovery ventilation, they are called earth tubes.
A cavity wall is a type of wall that has a hollow center. They can be described as consisting of two "skins" separated by a hollow space (cavity). The skins typically are masonry, such as brick or cinder block. Masonry is an absorbent material that can slowly draw rainwater or even humidity into the wall. One function of the cavity is to drain water through weep holes at the base of the wall system or above windows. The weep holes allow wind to create an air stream through the cavity that exports evaporated water from the cavity to the outside. Usually, weep holes are created by separating several vertical joints approximately two meters apart at the base of each story. Weep holes are also placed above windows to prevent dry rot of wooden window frames. A cavity wall with masonry as both inner and outer skins is more commonly referred to as a double wythe masonry wall.
Structural dampness is the presence of unwanted moisture in the structure of a building, either the result of intrusion from outside or condensation from within the structure. A high proportion of damp problems in buildings are caused by ambient climate dependent factors of condensation and rain penetration. Capillary penetration of fluid from the ground up through concrete or masonry is known as "rising damp" and is governed by the shape and porosity of the construction materials through which this evaporation limited capillary penetration takes place. Structural damp, regardless of the mechanisms through which it takes place, is exacerbated by higher levels of humidity.
Damp proofing or a Damp-Proof in construction is a type of moisture control applied to building walls and floors to prevent moisture from passing into the interior spaces. Dampness problems are among the most frequent problems encountered in residences.
Building insulation materials are the building materials which form the thermal envelope of a building or otherwise reduce heat transfer.
A crawl space is an unoccupied, unfinished, narrow space within a building, between the ground and the first floor. The crawl space is so named because there is typically only enough room to crawl rather than stand; anything larger than about 1 to 1.5 metres would tend to be considered a basement.
The word cellulose comes from the French word cellule for a living cell and glucose which is a sugar. Building insulation is low-thermal-conductivity material used to reduce building heat loss and gain and reduce noise transmission. Cellulose insulation is plant fiber used in wall and roof cavities to insulate, draught proof and reduce free noise.
Mold or mould, also sometimes referred to as mildew, is a fungal growth that develops on wet materials. Mold is a natural part of the environment and plays an important part in nature by breaking down dead organic matter such as fallen leaves and dead trees; indoors, mold growth should be avoided. Mold reproduce by means of tiny spores. The spores are like seeds, but invisible to the naked eye, that float through the air and deposit on surfaces. When the temperature, moisture, and available nutrient conditions are correct, the spores can form into new mold colonies where they are deposited. There are many types of mold, but all require moisture and a food source for growth.
A rainscreen is an exterior wall detail where the siding stands off from the moisture-resistant surface of an air/water barrier applied to the sheathing to create a capillary break and to allow drainage and evaporation. The rainscreen is the cladding or siding itself but the term rainscreen implies a system of building. Ideally the rainscreen prevents the wall air/water barrier from getting wet but because of cladding attachments and penetrations water is likely to reach this point, and hence materials are selected to be moisture tolerant and integrated with flashing. In some cases a rainscreen wall is called a pressure-equalized rainscreen wall where the ventilation openings are large enough for the air pressure to nearly equalize on both sides of the rain screen, but this name has been criticized as being redundant and is only useful to scientists and engineers.
