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  2. Pound per hour - Wikipedia

    en.wikipedia.org/wiki/Pound_per_hour

    Pound per hour is a mass flow unit based on the international avoirdupois pound, which is used in both the British imperial and, being a former colony of Britain, the United States customary systems of measurement. It is abbreviated as PPH, or more conventionally as lb/h.

  3. Mass flow rate - Wikipedia

    en.wikipedia.org/wiki/Mass_flow_rate

    Mass flow rate is defined by the limit [3] [4] ˙ = =, i.e., the flow of mass through a surface per time .. The overdot on ˙ is Newton's notation for a time derivative.Since mass is a scalar quantity, the mass flow rate (the time derivative of mass) is also a scalar quantity.

  4. PPH - Wikipedia

    en.wikipedia.org/wiki/PPH

    Pound per hour (symbol pph), mass flow unit (used in aviation to measure fuel flow, for instance) Part per hundred (percentage) People per hour, a measure of the rate of flow of people moving past a fixed point or through a system; Propylphenidate, an analogue of methylphenidate

  5. Air changes per hour - Wikipedia

    en.wikipedia.org/wiki/Air_changes_per_hour

    Air changes per hour, abbreviated ACPH or ACH, or air change rate is the number of times that the total air volume in a room or space is completely removed and replaced in an hour. If the air in the space is either uniform or perfectly mixed, air changes per hour is a measure of how many times the air within a defined space is replaced each hour.

  6. Per-unit system - Wikipedia

    en.wikipedia.org/wiki/Per-unit_system

    Conversion of per-unit quantities to volts, ohms, or amperes requires a knowledge of the base that the per-unit quantities were referenced to. The per-unit system is used in power flow, short circuit evaluation, motor starting studies etc. The main idea of a per unit system is to absorb large differences in absolute values into base relationships.

  7. Infiltration (HVAC) - Wikipedia

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

    The infiltration rate is the volumetric flow rate of outside air into a building, typically in cubic feet per minute (CFM) or liters per second (LPS). The air exchange rate, (I), is the number of interior volume air changes that occur per hour, and has units of 1/h. The air exchange rate is also known as air changes per hour (ACH).

  8. Arbitrary unit - Wikipedia

    en.wikipedia.org/wiki/Arbitrary_unit

    In science and technology, an arbitrary unit (abbreviated arb. unit, [1] see below) or procedure defined unit [2] (p.d.u.) is a relative unit of measurement to show the ratio of amount of substance, intensity, or other quantities, to a predetermined reference measurement. The reference measurement is typically defined by the local laboratories ...

  9. Moisture removal efficiency - Wikipedia

    en.wikipedia.org/wiki/Moisture_removal_efficiency

    DOAS Diagram. Moisture Removal Efficiency (MRE) is a measure of the energy efficiency of any dehumidification process. Moisture removal efficiency is the water vapor removed from air at a defined inlet air temperature and humidity, divided by the total energy consumed by the dehumidification equipment during the same time period, including all fan and pump energy needed to move air and fluids ...