Systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more
Density and specific volume of air varies with elevation above sea level.
Calculate air change rates - equations in imperial and SI units.
Fresh air (make up air) rquirements - or recommended air change rates (ACH) for typical rooms and buildings like auditoriums, kitchens, churches and more.
Calculate air curtains or air screens in open doorways used to keep acceptable indoor comfort in buildings.
Online calculator to compute friction loss in air ducts.
Minor loss (pressure or head loss) coefficients for air duct components.
Typical air duct velocities in applications like ventilation systems or compressed air systems.
A major friction loss diagram for air ducts - Imperial units ranging 10 - 100 000 cfm.
A major friction loss diagram for air ducts - in imperial units ranging 10 000 - 400 000 cfm.
A major friction loss diagram for air ducts - SI units.
Head loss or major loss in air ducts - equations and online calculator for rectangular and circular ducts - Imperial and SI units.
The influence of temperature and air pressure on major friction loss.
Minor loss coefficient diagrams for air ductwork, bends, expansions, inlets and outlets - SI units.
Required duct area vs. air flow.
Air flow volume, duct size, velocity and dynamic pressure.
Air filters efficiency and arrestance.
Air heating buildings - heat supply vs. air flow and temperature.
Ventilation systems - air intakes and outlets - rules of thumbs.
Fan vs. motor speed in belt driven fans.
Calculate length and speed of belt and belt gearing.
Carbon dioxide concentration in a room may indicate air quality and ventilation system efficiency.
Exposure to Carbon Monoxide - CO and health effects.
Standard size of circular ventilation air ducts.
Ventilation systems can be classified by functions, distribution strategies or by ventilation principles.
Clean rooms virtually free of contaminants like dust or bacteria.
Clean room class limits according ISO Standard 14644-1.
Friction loss coefficients in pipes, tubes and ducts.
A quick selection guide of ventilation system in comfort environments.
Design procedure for ventilation systems - air flow rates, heat and cooling loads, air shifts according occupants, air supply principles.
The equal friction method for sizing air ducts is easy and straightforward to use.
Duct systems are commonly divided into three pressure classifications.
Calculate velocities in circular and rectangular ducts - imperial and SI-units - online calculator.
Circular ducts sross-sectional areas.
Thickness of sheet metal used in ductwork.
The velocity reduction method can be used when sizing air ducts.
Ductwork air leakage classes.
Recommended distance between ductwork support hangers.
Calculate pressure loss - or head loss - in ducts, pipes or tubes.
Rectangular equivalent diameter for air flows between 100 - 50000 cfm.
Capture velocities to avoid pollution products from galvanic baths, spray painting boxes and more contaminating the surrounding room and environment.
Sizing of exhaust hoods - air volume flow and capture velocities - online exhaust hood calculator.
Capturing air velocity in front of an exhaust outlet - online exhaust outlet velocity calculator.
The affinity laws can be used to calculate resulting volume capacity, head or power consumption when speed or wheel diameters are changed.
Fan classification established by AMCA.
Pressure, head, air flow volume and fan capacity diagrams.
High suction pressure at a fan inlet decreases the density of air - and should be corrected for proper selection of the fan.
The motor must be capable of accelerating the fan wheel to it's operating speed.
AHP - Air Horse Power and BHP - Brake Horse Power.
How to modulate fans and their capacities.
Power consumption and typical efficiencies of fans
Guide to troubleshooting fan problems.
The temperature and density of the air influences on the volume flow, pressure head and power consumption in a fan.
Convert rectangular and oval duct geometry to a equivalent circular diameter - online calculator with imperial and SI-units.
Calculate hydraulic diameter for pipes and ducts.
Ventilation required for attic areas.
Exhaust ventilation from garages and workshops.
Clearance tolerance for gas vent terminations vs. roof slope.
Ventilation and heat-recovery calculations, sensible and latent heat - online calculators - imperial units.
Classification of heat recovery efficiencies - temperature efficiency, moisture efficiency and enthalpy efficiency - online heat exchanger efficiency calculator.
Basic equations for heat transfer - selecting criteria for heaters and coolers in ventilations systems.
Sprayed coils, spinning discs and steam humidifiers.
Pressure head loss in HVAC dampers.
Draw HVAC diagrams online with this Google Drive drawing tool.
Recommended air velocities in HVAC ducts.
Recommended indoor temperatures in summer or winter.
A quick selection guide for ventilation systems/principles in industrial environments.
Recommended indoor temperature and humidity for common industrial products and production processes.
The Mechanical Energy Equation compared to the Extended Bernoulli Equation.
Air flow - volume and velocity - due to stack or flue effect caused by indoor hot and outdoor cold temperature difference.
Required air ventilation to handle odor and smell from persons.
Odor intensity from persons vs. room volume and ventilation.
Acceptable indoor air quality and required make up air.
Recommended supply air rates of outdoor air - with or without smoking - in rooms like banks, assembly halls, hotels and many more.
Concentration of a pollution in a limited space as a room depends on the amount of polluted material spread in the room, supply of fresh air, outlets positions and construction, principles used for supply and outlet from the space.
The difference between pumps, compressors, blowers and fans.
Velocity diagram for rectangular air ducts - metric units.
Commonly used metric dimensions for rectangular air ducts in ventilation systems.
Calculate hydraulic diameter for rectangular ducts - metric units.
Recommended relative humidity in production and process environments - like libraries, breweries, storages and more.
Air flow required to remove vapor production from a room.
Room area per person - may be used to calculate typical indoor climate loads.
Surface coefficients that can be used to calculate friction and major pressure loss for fluid flow with surfaces like concrete, galvanized steel, corroded steel and more.
In a wet scrubber process air is drawn through a mist of water made by spray nozzles, then through separators where water droplets with dust and particles are removed.
A rough guide to maximum air volume capacity of circular ducts in comfort, industrial and high speed ventilation systems.
Ductwork - weight of galvanized round spiral elbows.
Standard dimensions of spiral ducts - Imperial units.
The stack or flue effect occurs when the outdoor temperature is lower than indoor temperature.
The definition of STP - Standard Temperature and Pressure and NTP - Normal Temperature and Pressure.
Axial and propeller fans, centrifugal (radial) fans, mixed flow fans and cross flow fans.
Centrifugal, axial and propeller fans and their capacity ranges.
Inclined and vertical u-tube manometers used to measure differential pressure in flow meters like pitot tubes, orifices and nozzles.
Recommended air velocities in ventilation ducts
Required size of ventilation and air conditioning rooms according DIN 1946.
Pressure loss in ventilation system components like dampers, filters, heaters, coolers and more.
Dampers in ventilation systems may be classified through function, construction or leakage class.
Minor pressure or head loss in ventilation ducts vs. air velocity - minor loss coefficient diagram.
The efficiency of a ventilation system may be related to temperature and/or pollution concentrations.
Classification of air filters used in ventilation systems.
Some commonly used ventilation principles - short cut, mixed air, displacement and piston principle.
Size and capacities of air return intakes.