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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).
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.
Clean air delivery rate (CADR) is the amount of clean air an air cleaner provides to a room or space. When determining CADR, the amount of airflow in a space is taken into account. For example, an air cleaner with a flow rate of 30 cubic metres (1,000 cu ft) per minute and an efficiency of 50% has a CADR of 15 cubic metres (500 cu ft) per minute.
NFPA Clean Agent Retention testing (this type of testing is usually described as a door fan test rather than a blower door test) Duct leakage testing of forced air heating/cooling systems - both supply (vents) ducts and return ducts can be tested to determine if and how much they leak air. A duct test can be combined with a blower door test to ...
But a lot of this decorating often involves using a ladder, which can be risky. “People will often put themselves in a situation where their stability is compromised,” Bachmann says.
Diagramatic operation of a thermal wheel Ljungström Air Preheater by Swedish engineer Fredrik Ljungström (1875–1964). A thermal wheel, also known as a rotary heat exchanger, or rotary air-to-air enthalpy wheel, energy recovery wheel, or heat recovery wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of air-handling units or rooftop ...
However, the hot air must be pushed from the register with enough force (or "throw") so that it will cross the room and reach the window. If there is too little throw, the hot air will stop moving partway across the room, the cold air from the window will not be heated (creating the feeling of a cool draft), and air circulation will suffer. [9]
Cross-breezes work when two windows are opposite of each other. Cross ventilation is a natural phenomenon where wind, fresh air or a breeze enters upon an opening, such as a window, and flows directly through the space and exits through an opening on the opposite side of the building (where the air pressure is lower).