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  2. Building airtightness - Wikipedia

    en.wikipedia.org/wiki/Building_airtightness

    The relationship between pressure and leakage air flow rate is defined by the power law between the airflow rate and the pressure difference across the building envelope as follows: [16] q L =C L ∆p n. where: q L is the volumetric leakage airflow rate expressed in m 3 h −1; C L is the air leakage coefficient expressed in m 3 h −1 Pa −n

  3. Foam glass - Wikipedia

    en.wikipedia.org/wiki/Foam_glass

    It is a stable building exterior wall and roof insulation and sound insulation material. Foam glass does not absorb water. The cells are mostly closed, so there is no capillary rise. Foam glass has an operating temperature range of -200 to 450 °C and a small expansion coefficient (8 × 10 °C).

  4. Infiltration (HVAC) - Wikipedia

    en.wikipedia.org/wiki/Infiltration_(HVAC)

    Infiltration is the unintentional or accidental introduction of outside air into a building, typically through cracks in the building envelope and through use of doors for passage. [1] Infiltration is sometimes called air leakage. The leakage of room air out of a building, intentionally or not, is called exfiltration.

  5. Ductwork airtightness - Wikipedia

    en.wikipedia.org/wiki/Ductwork_airtightness

    The relationship between pressure and leakage air flow rate is defined by the power law model between the airflow rate and the pressure difference across the ductwork envelope as follows: q L =C L ∆p n. where: q L is the volumetric leakage airflow rate expressed in L.s −1; C L is the air leakage coefficient expressed in L.s −1.Pa −n

  6. Blower door - Wikipedia

    en.wikipedia.org/wiki/Blower_door

    Blower door tests are used by building researchers, weatherization crews, home performance contractors, home energy auditors, and others in efforts to assess the construction quality of the building envelope, locate air leakage pathways, assess how much ventilation is supplied by the air leakage, assess the energy losses resulting from that air ...

  7. R-value (insulation) - Wikipedia

    en.wikipedia.org/wiki/R-value_(insulation)

    The U-factor or U-value is the overall heat transfer coefficient and can be found by taking the inverse of the R-value. It is a property that describes how well building elements conduct heat per unit area across a temperature gradient. [6] The elements are commonly assemblies of many layers of materials, such as those that make up the building ...

  8. Discharge coefficient - Wikipedia

    en.wikipedia.org/wiki/Discharge_coefficient

    In a nozzle or other constriction, the discharge coefficient (also known as coefficient of discharge or efflux coefficient) is the ratio of the actual discharge to the ideal discharge, [1] i.e., the ratio of the mass flow rate at the discharge end of the nozzle to that of an ideal nozzle which expands an identical working fluid from the same initial conditions to the same exit pressures.

  9. CFD in buildings - Wikipedia

    en.wikipedia.org/wiki/CFD_in_buildings

    CFD stands for computational fluid dynamics (and heat transfer). As per this technique, the governing differential equations of a flow system or thermal system are known in the form of Navier–Stokes equations, thermal energy equation and species equation with an appropriate equation of state. [1]