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  2. Building airtightness - Wikipedia

    en.wikipedia.org/wiki/Building_airtightness

    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; ∆p is the pressure difference across the building envelope expressed in Pa; n is the airflow exponent (0.5 ≤ n ≤ 1) This law enables to assess the airflow rate at any pressure difference regardless the ...

  3. 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 ...

  4. National Fenestration Rating Council - Wikipedia

    en.wikipedia.org/wiki/National_Fenestration...

    NFRC labels provide performance ratings for such products in five categories: U-value, Solar Heat Gain Coefficient, Visible Transmittance, Air Leakage, and Condensation Resistance. [1] This allows architects, builders, code officials, contractors, home owners, and specifiers to compare the energy efficiency among products, and determine whether ...

  5. Duct leakage testing - Wikipedia

    en.wikipedia.org/wiki/Duct_leakage_testing

    Duct leakage test in the US. A duct leakage tester is a diagnostic tool designed to measure the airtightness of forced air heating, ventilating and air-conditioning (HVAC) ductwork. A duct leakage tester consists of a calibrated fan for measuring an air flow rate and a pressure sensing device to measure the pressure created by the fan flow.

  6. 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.

  7. 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

  8. Stack effect - Wikipedia

    en.wikipedia.org/wiki/Stack_effect

    The rising warm air reduces the pressure in the base of the building, drawing cold air in through either open doors, windows, or other openings and leakage. During the cooling season, the stack effect is reversed, but is typically weaker due to lower temperature differences.

  9. Air changes per hour - Wikipedia

    en.wikipedia.org/wiki/Air_changes_per_hour

    Air outside a building or taken from outdoors and not previously circulated through the system. Perfect mixing A theoretical airflow distribution pattern within a ventilated space where the supply air is instantaneously and uniformly mixed with the air in the space such that the concentration of all constituents in the air, and the age of air ...