The following items and information are needed to calculate air flow:. 97 kg/kmol for air m 18. This ultra calculator is special by allowing you to choose among a great variety of units (6 for diameter and 24 each for velocity and flow rate). If the power source can supply the process air flow but not the cylinder air flow, then an air tank will be helpful. Carter can sell the used equipment today to another airline for $5m, and its tax rate is 40%. VE is affected by intake type, camshaft grind and type, boost, and many other factors. Cooling Tower Efficiency Formula: Cooling Tower Efficiency. Air velocity (distance traveled per unit of time) is usually expressed in Linear Feet per Minute (LFM). For flows at lower pressure, consult more complete references. Prior to 450m years ago the earth's surface was rock; there was no soil anywhere. of these calculations, only a general description of the calculation methods are included here. 70 psia R 8314 J/kmol K r W 0. The continuity equation states that the mass of air entering a straight and sealed pipe system equals the mass of air leaving the pipe system. For air flow you can use the same calculation and assume that the gas is incompressible. The following calculations for water vapour concentration in air apply at ground level. Calculation for double pipe exchanger, air cooled exchanger, lmtd calculation, lmtd correction. 10 of the Annubar Flow Handbook (document number 00807-0100-1191, Rev BA). calculation of energy use due to air infiltration, either to get more accurate results earlier in the building process or to make better choices for how to prioritize when retrofitting an old building. If you do not know the flow rating of your compressor or you would like to calculate a leak rate for your compressed air system then you can use this flow calculator. Quantity of fresh air required (L/s) = Air change rate (changes per hr) x Room volume (m³) x 1000 3600 Note: 1000 is required to bring m³/hr to L/s 3600 Example: Calculate the ventilation requirements for the office computer room in the main example above if the air change rate was specified to be 2 changes per hour. With >90% ethylene selectivity, up to 59% ethylene yield, and favorable heat of reactions, the core-shell redox catalyst has an. With insufficient flow, the compressor will require breaks to rebuild pressure in the compressor’s reserve tank. 5 m/s) -Froude No is >1, so subcritical flow regime Air Flow in Sewers May 10, 2012 Page 24. Now we will change the air flow rate through Section 2 from 3400 CFM to 3000 CFM. c) Under no circumstances should the total area of air supply be less than one (1) square foot. Whether exhausting air or bringing fresh air into a structure, the calculation produced should help to figure out the size of fan(s) required to accomplish the air exchanges needed. Just enter the length, width and height (in feet) of the containment area along with the number of air changes required per hour. L = length of pipe, metres. It allows you to calculate the flow or C v (flow coefficient) to make the relationship visible between the pressure drop (the difference in pressure between two points in a network transporting a liquid or gas) and the flow rate. Q = A1 x V1 = A2 x V2 Q: flow (cfm) A: flow section (ft²) V: speed (ft/min) The international system of flow is cubic meters / second (m3/s), but we generally use l/s, m3/h or cfm. Pipe flow calculations. q is the flow in m 3 /s. To calculate the flow velocity we need the flow rate figure under operating conditions. One can also coarsely estimate the average mass flow rate. Volume Unit Conversion Calculator. This change can be used to measure the flowrate of the fluid. Cfm Calculation Formula. Comparison of a patient's current peak flow to a known or expected personal best is only one aspect of the evaluation of a child with an acute asthma exacerbation. Find the flow rate so that the concentration does not exceed 100 ppm. One thing you can take immediately from this equation is what’s called Bernoulli’s principle, which says that increasing a fluid’s speed can lead to a decrease in pressure. The pressure just “pushes” the air out, and with half the “push” you get half the air flow. Problem: Methyl Chloride evaporates from a tank at a rate of 0. Unlike liquids, gases are compressible, and the change in the conditions of the fluid as it moves down the pipe must be considered in these calculations. This is because of accuracy limitations of the measuring equipment and process. P 1 + 1 atmosphere. Ratio of volume flow Q and input pressure p1 abs for choked flow C=Q/p1 abs. In order for air to flow into, out of, or within a building, two requirements must be met: a hole or path must exist for the air to flow through, and there must be a driving force. FAN LAWS: Remember RPM is interchangeable for CFM. The table given below gives the discharge of air through an orifice in cu. To calculate COP, you need to measure 5 things: the exact temperature of the water entering the geothermal heat pump s water coil, the exact temperature of the water leaving the geothermal heat pump s water coil, the flow rate of the water through the geothermal in gallons per minute (GPM), the amps usage of the unit, and the exact voltage at. The primary aspects of a properly designed engine room ventilation system are cooling air and combustion air. Pipe flow calculations. ISO calibration certificate. The equipment originally co has $20m, of which 80% has been depreciated. Enter the R-value of the selected duct insulation. Author(s): Haves, Philip; Ravache, baptiste; Yazdanian, mehry | Abstract: The aim of the project reported here was to better understand the level of accuracy of three building energy simulation (BES) engines (‘engines’) — EnergyPlus™, DOE-2. 4 m^2, is to heat air (cp = 1005 J/kg. The formula for H (lbs/hr) is: H = Volume X Air Changes X Grains of Moisture Required Specific Volume X 7000 Grains of Moisture Required From psychrometric chart = 56 grains of moisture per pound of air at 70 o F and 50% RH, minus 9 grains of moisture per pound already in the air (56 - 9 = 47). If a filter is required, you should con sider the additional resistance to air flow. To calculate mass flow in lbs/min when volume in cfm (cubic feet per minute) is known, use the following: Let's calculate the mass flow of air when a value of 1000 SCFM (Standard Cubic Feet per Minute) is used. Driving Forces. You need the MW. By graphing the data of the percent change in mass of the potato cores, it can be determined that the water potential of potato cells is equal to the water potential of an unknown sugar solution molarity. ASCO Introduces Stainless Steel Redundant Control System (RCS) ASCO Introduces 068 Series Flapper Isolation Valve - Improves Throughput, Reduces Sample Size in Clinical and Analytical Instruments. 03 ∆ Formula to find flow rate for a gas when ∆. The effects on the predicted water flow are then given in three graphs where in turn two of the variables are kept constant. of attic area. Calculate the viscosity of natural gas with specified average gas pressure and. Calculate the beta ratio, Reynolds number, Discharge coefficient, Mass and Volumetric flow rate of a Newtonian fluid through an orifice with a Corner, 1D - ½ D, or Flange tap arrangement. A fluid includes all liquids and gases. Related Articles:. 3208 / inside area of the pipe (sq ins) Circle area formulas: Area (sq ins) = π x r² where π (pi) = 3. The density needs to be adjusted appropriately using the ideal gas formula. For practice use an air flow of 80 cubic feet per minute and it will equal 115. Imagine a column of liquid above an area 1 ft by 1 ft. Example: Calculate the IV flow rate for 200 mL of. All Sensors Pressure Points are application tips to simplify designing with microelectromechanical systems (MEMS) pressure sensors and avoiding common pitfalls. Calculate pump flow rate from a change in impeller diameter. Solution:. The air flow rate through a ventilation inlet opening forced by wind can be calculated using the formula Q = Cv x A x v where: Q = air flow rate (m 3 /s) Cv = effectiveness of the openings (assumed to be 0. The above are representative flows for estimating purposes. 1m³ x (2100W/15 º C ) = 434 m³/h (the required air flow) In summary, calculating fan flow is not a difficult exercise as long as time is taken to work through each step in. Pipe Sizing by Pressure Loss; Pipe Sizing by Velocity; Pressure Loss through Piping; Air Velocity through Piping; Air Flow Rate through Piping; Valves and Orifices. Using the explanation above the water potential of the potato cells can be determined. In the case of a sharp-edged orifice, the effective diameter is 0. Our Flow Rate Calculator will calculate the average flow rate of fluids based on the bore diameter, pressure and length of the hose. Mass air flow (MAF) is calculated using the volume air flow as determined and explained above, and a value for density calculated from the temperature and pressure near the air filter. This example has been derived for the dry air of the standard conditions. In fact, we know from Boyle's Law that: P1 x V1 = P2 x V2. To calculate the airflow with an inlet pressure of 80 PSIG (5. In this case, it is important to be able to increase the air volume of the exhaust blower and hood supply. Compressor Terms you should know: Cubic Feet Per Minute (cfm) – Volumetric air flow rate. Due to the complexity of their geometry (Fig. Important codes that paint booths comply with include National Fire Code 1, NFPA 33, OSHA, and a few others. At the same flow, a larger duct will reduce air velocity, perhaps enough to diminish performance. For example, 440 CFM of air flows through a 4" duct at around 5,000 FPM. 746 x hours x KWH cost ÷ motor efficiency. This can be accomplished with a standard reducer flipped upside down and used as an. It is only an aid to check calculations that qualified Nitrox Divers and Blenders perform. To arrive at your required CFM, simply divide your bathroom's volume by 7. Starting with a review of basic equations, calculations, and featuring many examples, this handy reference offers a quick look-up of topics such as drilling fluids, pressure control, engineering calculations, and air and gas calculations. 2250 kg/m 3. CFM = 400 delta T = 15*F BTU/hr = 1. 0 ºC, (68 ºF) Pn = 1. 187 x (20/15) x [540. Units for gas calculations Volumetric air flow Equipment is based on standard conditions— need to convert to actual conditions for design CFM = cubic feet per minute SCFM = standard cubic feet per minute ACFM = actual cubic feet per minute 460 standard temp 460 actual temp actual pressure 1 atm ACFM SCFM + + = × ×. Static pressure is directly related to duct surface material, duct distance and design, HVAC equipment obstacles and volume of air. The discussion, calculations, and examples presented in this Guide are generally in terms of volume flow rates based on standard air properties. 3 cubic feet of standard air = 1 pound. Flow of air or any other fluid is caused by a pressure differential between two points. Calculating the air consumption for a single-acting cylinder is a rather easy calculation, but it is important to understand that the required air flow is dependent not only on the bore area and stroke, but also the cycle rate of the pneumatic cylinder. Compensating Hood – A hood that has an outside air-supply with air delivered below or within the hood. answered Apr 21 '15 at 16:42. The application is a complex with unique dimension and content comprizing 70 calculations critical both for professional and entry-level HVAC engineer. For practice use an air flow of 80 cubic feet per minute and it will equal 115. critical flow, and critical (or choked) flow. 93 ft/min average air speed across the face of a 12 inch (1 foot) diameter fan. Nothing is as good as actual air-flow readings and use above formula for CFM. - Medium pressure supply lines should be sized so the fluid velocity is between 15 and 20 feet per second. The default values are for air flow 400 cfm (680 m 3 /h), duct size 8 in (200 mm) and velocity 1150 fpm (5. Next type the circular duct dimensions of r = 2 in. A compressor is going to operate under varying values of the variables affecting its performance. Intake or exhaust restrictions, engine timing faults, and air measurement faults are all common causes of low VE. Air flow meter to measure air temperature and velocity with calculation of volume of air current and RS-232. Tube diameter: d (mm) Tube length: L (m) Flow Q (Nl/min) Input pressure (relative atmosphere) Output pressure (relative atmosphere) Input absolute pressure. All you need to do is enter your tank size, initial pressure, final pressure, and the time it took and the calculator will do the rest. 95: Peak RPM: Enter peak RPM: Displacement in Cubic Inches: Engine displacement in cubic inches. Intake or exhaust restrictions, engine timing faults, and air measurement faults are all common causes of low VE. Using the Steam Property Calculator, properties are determined using Inlet Pressure and the selected second parameter (Temperature, Specific Enthalpy, Specific Entropy, or Quality). C V & FLOW CALCULATOR. 1416 and r = radius in inches. It is recommended to consult a reference manual when performing calculations to size your system. Is related with turbulent flow and the restriction the devices makes to the flow. In this case, it is important to be able to increase the air volume of the exhaust blower and hood supply. Each lateral is oriented at ninety degree to manifold axis. The Excel formulas use an. Also the required pipe diameter to carry a given flowrate with a maximum allowable head loss can be calculated. evacuation, fire floor evacuation and whole building evacuation. 21)) This calculator estimates the temperature drop (or rise) of air flowing in a duct. This means how much volume of compressed air can be generated by an air compressor when it has run for a particular amount of time. Now you can read the correct pipe size (in mm diameter) in the table. Fa = Loss of energy of air Ws = Mass of solid Wa = Mass of air RECOMMENDED VELOCITIES FOR VENTILATION SYSTEMS Function Type Public Buildings (m/s) Industrial Plants (m/s) Air intake from outside 2. This table is for 7 bars and maximum 0. For example if we have a 4 cylinder engine developing 200hp it would be flowing around 300 SCFM or 23 lbs. Airflow is the volume of air moved by a fan per unit of time, usually expressed in cubic feet per minute (cfm) or meters cubed per second (m³/s). Flow of Air in Pipes Equation and Calculator. For laminar flow, resistance is quite low. 12 KWH electric rate and a 90% efficient electric motor. TDS Calculator. If you want to work this out in mass flow, a standard cubic foot of air weighs about 0. I understand it is flowing more air than it is looking for, but I haven't been successful in harnessing that in yet. All you need to do is select the application from the dropdown, enter the size of the room and we will provide you with a general capacity range (m3/hr) that you should be looking to achieve from the extraction fan. 3 cubic feet of standard air = 1 pound. of attic area. Note: The duct wall is considered to be of negligible thickness. Actually, I need to calculate the exhaust air flow rate for Hydrogen ICE car because I need to circulate the exhaust air for another purpose. 14) Where: A = cross sectional area if the pipe bore in square inches or ∏ x diameter squared / 4 Q = Flow rate SCFM. Flow chemistry specialist Uniqsis, based in Cambridge, UK, and Boston, MA, USA, supplies FlowSyn continuous flow reactors (also known as plug flow reactors, micro flow reactors or microreactors) for pharma and scale up chemistry applications. 0)to a liquid having a specific gravity other than 1. Given the high performance of the baseline impeller, the redesign adopted a high. Flowrate (CFM): #N#Cross Sectional Flow Area (sq. In summer season the ambient air wet bulb temperature raises when compared to winter season so cooling tower efficiency limiting in summer season. p is pressure in KPA. Flow rate can also be articulated as in a given time (t) the capacity of fluid stored (C). Each has built in Excel formulas to calculate unknowns like the pipe flow. Reynolds Number Calculations. ) So the standard 16-inch-by-8-inch soffit vent is 0. Flow Handbook Annubarﬁ Primary Element Flow Calculations ANNUBAR PRIMARY ELEMENT FLOW EQUATIONS The Annubar primary element flow equations are all derived from the hydraulic equations which are shown in equations 2. Cut away the perforated area in front of the fan and install a finger guard. Flow is the ability of an air compressor to continuously perform a task. Counter Flow Heat Exchanger Calculator. Unlike liquids, gases are compressible, and the change in the conditions of the fluid as it moves down the pipe must be considered in these calculations. most calculations only use the heat loss or gain of a room to decide on required airflow and often don't take into consideration required room ventilation needs. Therefore, to find the velocity V_e, we need to know the density of air, and the pressure difference (p_0 - p_e). The air flow at 135 psi = 6. Dilution Ventilation and Heat Control. Levels of Contaminant Control Pressurization is one tool Physical barrier is also BSL 1 - Laboratories. In 2018, 120. Volumetric air flow. 10 of the Annubar Flow Handbook (document number 00807-0100-1191, Rev BA). The Gilian Gilibrator ® I and II by Sensidyne ® (see Figure F-1) are electronic bubble flow meters, used to calibrate sampling pumps, that provide instantaneous air-flow readings and cumulative averaging of multiple measurements. Total Pressure, Velocity Pressure, and Static Pressure. Dust collection and air filtration systems that filter out the contaminants and recycle the cleaned air will save the energy costs incurred when venting contaminated air to the outside and thus having to heat or cool the replacement air. The Air Flow in CFM is 6,128 Ft³/Min Air Flow in CFM (Q) = Flow Velocity in Feet Per Minute (V) x Duct Cross Sectional Area (A) Air Flow in CFM (Q) = 3,468 Ft/Min x 1. Call Infiltec toll-free (888) 349-7236 for assistance. It is determined at the four corners and the center of the filter and the mean of the five readings are determined. I N S T R U C T I O N S. 59352) is computed from reference conditions, so it never changes. Air velocity is a function of air density and differential pressure, but determining air flow requires that the geometry of the piping be taken into account. 05 cfm of air flow •Generalized Case -Pipe = 72-inch RCP -Pipe wall friction factor = water surface friction factor -Pipe Slope = 0. Fan & motor CALCULATIONS, Pulley size, RPM, air flow rate cfm hvac rtu - Duration: 9:58. Normally we do not have an online density measurement. By the same principle when subjected to very low pressure (<1 psig), air will flow approximately 53 times more units of volume through a hole than water if the water is able to flow at all. This change can be used to measure the flowrate of the fluid. Do this with a case intake fan. The term pipe flow in this course is being taken to mean flow under pressure in a pipe, piping system, or closed conduit with a non-circular cross-section. Enter your values in the boxes. 3), simple analytical air flow calculations as well as airflow networks typically cannot include their full geometry as input parameters; they include a flow effective area Aeff and effective height H2 together with a discharge coefficient Cd to describe the equivalent area of the rectangular. From a calculation viewpoint alone, the power calculation is particularly sensitive to the specification of mass flow rate, suction temperature and pressure, and discharge temperature and pressure. should be kept free for air flow. The calculations can be performed for either liquid. All you need to do is select the application from the dropdown, enter the size of the room and we will provide you with a general capacity range (m3/hr) that you should be looking to achieve from the extraction fan. c) the system noncoincident calculation simply adds up the zone peaks (chosen by flowrate and hence from the winter DD) and gets the design MAT from the flow-weighted average MAT of the zones at the time and the DD of the zone peaks. The Ariel Performance Software includes calculations for predicting the flow, power, temperatures, pressures, gas rod loads, crosshead pin load reversals as well as other values for the predictions and limitations of the compressor applications. Moreover, if the fume hood exhausts air outside the building, like with a BSC, the exhausted air must be replaced with fresh air. To calculate COP, you need to measure 5 things: the exact temperature of the water entering the geothermal heat pump s water coil, the exact temperature of the water leaving the geothermal heat pump s water coil, the flow rate of the water through the geothermal in gallons per minute (GPM), the amps usage of the unit, and the exact voltage at. It calculates both rectangular and round duct dimensions. september 14, 2018. c) Under no circumstances should the total area of air supply be less than one (1) square foot. Calculations for power fan installations If you plan on installing a power fan, you can calculate intake and exhaust requirements using the following formulas: 1. SCFM Conversion Calculator. Problem: Methyl Chloride evaporates from a tank at a rate of 0. 00, first convert the 243 SCFM to the equivalent flow expected on a valve having a Cv of 1. On average, each home consumed 12,146 kWh of delivered electricity (EIA 2019a). The formula to calculate this is: A = 144 * Q * Pa V *60 x (Pd +Pa) Pipe Diameter = √ (A*4/3. 53 Carbon Monoxide 0. Calculate pump speed RPM with an increase or decrease in flow rate. From a calculation viewpoint alone, the power calculation is particularly sensitive to the specification of mass flow rate, suction temperature and pressure, and discharge temperature and pressure. FAN LAWS: Remember RPM is interchangeable for CFM. Process Flow Calculation. Using the explanation above the water potential of the potato cells can be determined. 158 BAR + 1. Refer to EnggCyclopedia’s ‘Sample Solved problem for - Venting Calculation for Inbreathing due thermal shrinking of fluids’, for demonstration of these venting calculations. This calculation does depend on the type of cylinder you are using, particularly whether it is a single-acting cylinder or a double-acting cylinder. If you have mass flow of ethanol, convert to molar flow by dividing by the molar mass, 46 g/mol. The table given below gives the discharge of air through an orifice in cu. If we want to maintain same pressure in the room, we should supply the amount of air which is leaking out. The calculator will tell you the cfm range you need. Online calculator analyzes the air flow required to pressure test the airtightness of a large building with one or more calibrated fans. 92” HG (Mercury) 1 cubic foot of standard air = 0. The formula for the air consumption of a single-acting cylinder is as follows:. Two formulas can be used. Pascal calculations to express building pressure & air infiltration rates: This article explains methods of measuring building air infiltration rates and the related calculations of pascals. Equipment is based on standard conditions— need to convert to actual conditions for design CFM = cubic feet per minute SCFM = standard cubic feet per minute ACFM = actual cubic feet per minute 460 standard temp 460 actual temp actual pressure 1 atm ACFM SCFM + + = × ×. See also a map, estimated flight duration and the time difference between cities. Flow Rate Calculator. CFM = Duct area sq ft x Velocity Standard Air= 70F @ 29. For example, 440 CFM of air flows through a 4" duct at around 5,000 FPM. 085 * SCFM * (LAT - EAT). With restrictions and limitations. Please note that this page is not intended as the sole means of calculating Nitrox Blends, MODs, EADs, or other information it offers towards the planning of a Nitrox dive. 1) Where: L = the thickness of the wall in inches. ) point of a system you can use the Fan Laws to calculate the pressure loss for other air flow rates. as for natural ventilation airflOW calculations. 82 Hydrogen Chloride 1. Cfm Calculation Formula. 1 Input Conditions Variable Value Unit (SI) Value Unit (IMP) D 0. nitrogen for the RTA). Do this with a case intake fan. Specific Gas Constant, R value in J/kg. Use in patients age 5-80 years with asthma. Define the air flow application. ) Now to calculate the air flow: Q is in CFM (cubic feet per minute) V is in feet per minute. Determining Volume Flow. Flow Meter Reading: Pressure Indication at Exhaust of Flow Meter (Gage Pressure) Air Temperature in degrees F : SCFH Corrected for Temperature and Pressure: CALCULATE READING FOR DESIRED SCFH – Enter required information in colored cells: Desired SCFH: Pressure Indication at Exhaust of Flow Meter (Gage Pressure) Air Temperature in degrees F. TDS Calculator. 70 psia R 8314 J/kmol K r W 0. Easy like a feather. (Area of circle =þ d2/4; where d = diameter in feet). is the pressure exerted by the air around us. 6 (Pounds-per-Pound) x FUEL FLOW (pph) But airflow is usually discussed in terms of volume flow (Standard Cubic Feet per Minute, SCFM). Example: A Model 3215 Vortex Tube consumes 15 SCFM at 100 PSIG (425 SLPM @ 6. 29 g/mol (you can look up precise equiv. 05 cfm of air flow •Generalized Case -Pipe = 72-inch RCP -Pipe wall friction factor = water surface friction factor -Pipe Slope = 0. The pressure just “pushes” the air out, and with half the “push” you get half the air flow. 075 pounds 13. Use this same volume of air for the exhaust system, but then correct for thermal expansion (you need to know exhaust temps to figure things out). The value given is for a straight pipe without any. c) the system noncoincident calculation simply adds up the zone peaks (chosen by flowrate and hence from the winter DD) and gets the design MAT from the flow-weighted average MAT of the zones at the time and the DD of the zone peaks. The parameter that becomes "choked" or "limited" is the fluid velocity. Most methods of flow measurement are nonlinear. Above 10%, normal bubble flow ceases and the efficiency of the airlift drops rapidly. Normally we do not have an online density measurement. For example, a model SSX160241 is a 2 Ton (24,000 BTU) air conditioner. FREE AIR DELIVERY (FAD) Measured in CFM (Cubic feet per minute) this is the amount of compressed air converted back to the actual inlet (free air) conditions before it was. 4 F -V m 77. Air Flow Calculator Instructions: Using the size of your containment and required air changes per hour (ACH), our air flow calculator is designed to assist you in choosing the best OmniAire machine for your application. 03 psi on opposite sides of a door would be considered extremely high. Volume flow is usually measured in Cubic Feet per Minute (CFM). Usually, the Kv-value is given in the product description or datasheet. Calculate air velocity, metres/second from pressure difference (Pitot) The standard air density at 20°C and 1013mb barometric pressure is 1. Quantity of fresh air required (L/s) = Air change rate (changes per hr) x Room volume (m³) x 1000 3600 Note: 1000 is required to bring m³/hr to L/s 3600 Example: Calculate the ventilation requirements for the office computer room in the main example above if the air change rate was specified to be 2 changes per hour. The Cv was designed for use with liquid flows, it expresses the flow in gallons per minute of 60º F water with a pressure drop across the valve of 1 psi. To adequately supply this profile the system would require two running 100-hp compressors for the 600 cfm flow but would only need a single compressor part loaded at the lower 200 cfm flow. of vent space for every 150 sq. Calculating Air Velocity — Air velocity can be calculated from the following formula: Velocity (fps) = Flow (ACFM) Area of Heater (ft 2) x 60 sec. 0 A typical entry might be. 240 kcal/kg/°C at 90°C and ca 2 = 0. The volumetric flow rate formula used by this calculator is: t = V / Q. water) is equal to about 25 Pascals (Pa). Compact single stage pressure regulators for applications where space is limited, such as inside a process tool. 59352) is computed from reference conditions, so it never changes. For example if we have a 4 cylinder engine developing 200hp it would be flowing around 300 SCFM or 23 lbs. Once the volume of air in standard cubic feet per minute (SCFM) and the required temperature rise in °F (ΔT) are known, the required kilowatt rating (KW) of the heater can be determined from the following formula: convert the flow rate to SCFM using the formula given earlier. H2O) Round Duct Equivelent of Rectangular Duct. These tests will develop relationships that will ultimately allow the formula team to predict the heat rejection necessary at every car speed as well as the ability of a particular radiator to reject. org are unblocked. Hollow, tubular steel piles, which are the subject of CalQlata's piling calculator, are generally used as anchors or to prevent movement in small to medium structural foundations in suspect soil conditions either on land or in the seabed. Therefore, humid air is lighter than dry air. The required rates of air supply are determined to meet all the criteria imposed to verify the safety requirements at these three stages of evacuation. T = averaging time (minutes). making this calculator quite versatile. engine air flow rate - cubic feet per minute: CID = engine displacement, size or volume - cubic inches: RPM = engine speed - revolutions per minute: NOC = number of cylinders: BORE = length: STROKE = length: HGV = head gasket volume: HGCT = head gasket compressed thickness: PDV = piston deck volume: DPD = deck to piston distance: VPD = volume. When flow-meters are under pressure the flow must be calculated for the pressure to provide accurate flow readings. We will illustrate how once you know one (CFM, S. HVAC COOLING LOAD CALCULATIONS AND PRINCIPLES Sensible Heat Gain - is the energy added to the space by conduction, convection and/or radiation. of vent space for every 150 sq. Inches Needed Total Square Inches Required Round Pipe Size thru 3" 14" 4" 15" 5" 16" 6" 17" 7" 18" 8" 19" 9" 20" 10" 21" 11" 22" 12" 23" 13. Equations displayed for easy reference. Volume flow is usually measured in Cubic Feet per Minute (CFM). The CFM calculator refers to the volume of air that comes out of a leaf blower’s tube in one minute. t = Time; V = Volume. The continuity equation states that the mass of air entering a straight and sealed pipe system equals the mass of air leaving the pipe system. Valve coefficient (Cv) is a number which represents a valve's ability to pass flow. 30,720 cubic feet ÷ 60 minutes = 512 CFM range hood fan or higher. Determining Air Volume by Calibrated Resistance Manufacturers of air. P 1 + 1 atmosphere. 2) Water is flowing down an open rectangular chute. To calculate the flowrate of a fluid passing through an orifice plate, enter the parameters below. 5 5-6 Air cleaners 2. For laminar flow, resistance is quite low. Go to the Free Area Chart and select a louver that has a free area equal to or greater than the value found in item # 4. Pressure and Flow rate Pressure Definition Absolute Pressure: Absolute pressure is the force per unit area applied to anything, whether that anything is a solid, liquid or gas. Then divide by the volume of the room in cubic feet: In plain English, we're changing CFM into Cubic Feet per Hour (CFH). KVAR consumed by a Motor = KW x tan (cos-1 (p. 93 ft/min average air speed across the face of a 12 inch (1 foot) diameter fan. V ot = 120 cfm. Units for gas calculations Volumetric air flow Equipment is based on standard conditions— need to convert to actual conditions for design CFM = cubic feet per minute SCFM = standard cubic feet per minute ACFM = actual cubic feet per minute 460 standard temp 460 actual temp actual pressure 1 atm ACFM SCFM + + = × ×. The SI Derived Unit for volume based flow rate is cubic meter/second. Now we will change the air flow rate through Section 2 from 3400 CFM to 3000 CFM. Diesel and Turbo charged engines could result with higher than 90% efficiency if in good shape. Mass air flow (MAF) is calculated using the volume air flow as determined and explained above, and a value for density calculated from the temperature and pressure near the air filter. The Kv-value is a measure of the flow rate through a valve for a given medium and pressure drop. Flow rate formula has extensive applications in fluid dynamics to compute the velocity, area or flow rate. To calculate air flow capacity of a fan in cubic feet per minute (cfm): multiply the average air speed you measured in feet/minute (fpm) by the area of the fan face in square feet. Design Calculations • Design Flow: 8,000 gal/day Design flow calculated from the Magnolia Utilities monthly water bill for the mobile home park. The basic formula for frictional resistance is similar though; namely, R = Cf × S × V² with a new coefficient of friction (Cf) now varying with the Reynolds Number, according to charts by various researchers. This may be calculated as follows: Accordingly in our example the flow rates upstream and downstream of the valve are as follows: The pipeline diameter can be calculated as follows: If in our example maximum flow velocities of 20 m/s upstream and 15. Solve simple and complex fluid flow problems in less than one minute GUARANTEED. The tank has a hole in it. The bores are actually “fighting” for the same air. A general rule of thumb is that a 5hp motor can produce 10 CFM at 100psi. The logging instruments are manufacturer calibrated and are delivered incl. Static pressure is directly related to duct surface material, duct distance and design, HVAC equipment obstacles and volume of air. FREE AIR DELIVERY (FAD) Measured in CFM (Cubic feet per minute) this is the amount of compressed air converted back to the actual inlet (free air) conditions before it was. Wall thicknesses are: 1/8" tube, 0. So I need to reduce the CPU temperature by approximately 6% (1 - 333/353). Did you find us useful? Please consider supporting the site with a small donation. this is the largest commercially available thermoelectric air conditioner anywhere. ) Now to calculate the air flow: Q is in CFM (cubic feet per minute) V is in feet per minute (fpm). GPM = Gallons Per Minute. engine air flow rate - cubic feet per minute: CID = engine displacement, size or volume - cubic inches: RPM = engine speed - revolutions per minute: NOC = number of cylinders: BORE = length: STROKE = length: HGV = head gasket volume: HGCT = head gasket compressed thickness: PDV = piston deck volume: DPD = deck to piston distance: VPD = volume. Recirculating Air Volume. HVAC design calculation used by professional mechanical engineers for Chiller Fans,Centrifugal Pumps,axial fans air,heat transfer for fluids. Other common terms for this constant are K-constant or pickup gain. The formula for the air consumption of a single-acting. Calculate flow rate. Sal introduces the notion of moving fluids and laminar flow. What would his alveolar ventilation/minute be? A patient with a respiratory rate of 12, tidal volume of 500mL and weight is unknown. Prior to 450m years ago the earth's surface was rock; there was no soil anywhere. Engineering Toolbox: Duct Velocity. A general rule of thumb is that a 5hp motor can produce 10 CFM at 100psi. The use of this flow coefficient (Cv) calculator leads to a standard calculation. Therefore, for a given heat load dissipated by the server, the correct airflow rate should lead to a 20°F temperature rise as the cooling air travels through the server. Reynolds Number Calculations. Calculate the total volume of the vacuum system in cubic feet. Solve simple and complex fluid flow problems in less than one minute GUARANTEED. In summer season the ambient air wet bulb temperature raises when compared to winter season so cooling tower efficiency limiting in summer season. 0 Heater connection to fan 3. Home › Knowledge Base › Categories › Calculators › Orifice Size Calculator. More than 200K calculations per year. ): Round Duct Equivalent Diameter (in. making this calculator quite versatile. of free Air per minute at atmospheric Pressure of 14. Air Flow Pressure Calculator Available in English. The small bore spreadsheets are for pipes with diameters between 12 inch and 1 1/2 inches (12 mm to 40 mm), and use slightly different equations from ASME MFC-14M:2001. It is determined at the four corners and the center of the filter and the mean of the five readings are determined. Download Word document. 696 PSIA, Normal = 0°C & 1. The tank has a hole in it. Besides previously mentioned airflow calculations, multiplying, reading and measuring errors, four bores will not flow four times what one bore will flow when they are close together, as in a 4 barrel carburetor. The formula permits us to calculate the theoretical curves (pressure drop vs. 1 – 50 cfm/fixture – toilets in ashrae 170 – 10 ach of exhaust air • per ashrae 170 - the more stringent criteria prevails. 8) Where w = cubic foot per minute of air circulation flow i = denotes inside air temperature. The relative humidity is the percent of saturation humidity, generally calculated in relation to saturated vapor density. static pressure characteristics and the pressure loss of the object to be cooled. Output absolute pressure. 3 is concerned with ventilation, infiltration, air flow around buildings, and the re-entry of exhausts, including their interactions with indoor air quality, HVAC system performance, and energy consumption. The formula to calculate this is: A = 144 * Q * Pa V *60 x (Pd +Pa) Pipe Diameter = √ (A*4/3. Flow Calculation Formulae Cv Formulas. Calculate for each individual room. Select a fan using the required air flow. If the system is a dedicated outdoor-air system or 100% outdoor-air system, the designer would run the same calculation on all 16 zones and then use equation 6. Use this formula for electrical energy calculation: Electrical cost = Total HP x. Carter can sell the used equipment today to another airline for $5m, and its tax rate is 40%. Use this online Physics conversion CFM calculator to calculate the air flow of a pipe. If the upstream pressure (P1) is less than two times the downstream pressure (P2), the formulas for sub-critical flow should be used. Flat Panel: Length x Width x 6. With this information you can calculate the air flow through the three-inch pipe. 746 (Power Factor) X Hours. Example: A Model 3215 Vortex Tube consumes 15 SCFM at 100 PSIG (425 SLPM @ 6. Florida Air Designs, Inc. What do we know about larger throttle body flow and torque calculations at or near idle? Working with a monster throttle body on a big blower Hellcat, only issue left with the car is if left idling it throws these two codes. Since then, soil has. So assuming you have an area of 1 m^2 with a velocity of 1 m/s, air with a density of 1. 3 million homes in the United States consumed 1,462 billion kilowatt-hours (kWh) of electricity (EIA 2019a). What good is all this? The multiplier (. Calculating flow rate in an enclosure a first in the field of thermoelectric cooling, teca introduces the ahp-6263 model with a half ton of cooling capacity. The equipment originally co has $20m, of which 80% has been depreciated. Important codes that paint booths comply with include National Fire Code 1, NFPA 33, OSHA, and a few others. Use this formula for electrical energy calculation: Electrical cost = Total HP x. Determine the fan capacity needed to provide about 10 to 12 air exchanges per hour. SCFM Conversion Calculator. Calculate the beta ratio, Reynolds number, Discharge coefficient, Mass and Volumetric flow rate of a Newtonian fluid through an orifice with a Corner, 1D - ½ D, or Flange tap arrangement. With >90% ethylene selectivity, up to 59% ethylene yield, and favorable heat of reactions, the core-shell redox catalyst has an. Calculate the total volume of the vacuum system in cubic feet. There are also spreadsheets for large bore orifice meter calculations for liquid flow and for small bore orifice meter calculations (gas flow or liquid flow). On average, each home consumed 12,146 kWh of delivered electricity (EIA 2019a). Computation of Natural Gas Flow Rate using a Spreadsheet Ayoade KUYE and Uzoma EZUMA Department of Chemical Engineering, University of Port Harcourt, PMB 5323, Port Harcourt, NIGERIA E-mail: ao. designing the intake system are its flow and acoustic performance. 4 Nozzle Flow meter A flow nozzle consists of a restriction with an elliptical contour approach section that. Cooling Tower Efficiency Formula: Cooling Tower Efficiency. Calculation include pressure losses in pipe and fittings, natural gas pipe sizing, two phase flow, pump sizing and compressor rating. Convert between many different pressure equivalents. After, of course, removing the cover. Start by separating the two measurements. The calculator will tell you the cfm range you need. Determining Volume Flow. The calculations can be performed for either liquid. 013 BarA; these standard conditions are one choice among many standards. 15 to 20 ft/sec = pressure lines 500 - 3,000 psi. 225 (Kg)/m^3` Frontal Area, `A=0. To arrive at your required CFM, simply divide your bathroom's volume by 7. For flows at lower pressure, consult more complete references. ET Operator Good morning, ladies and gentlemen, and welcome to the Howmet Aerospace. Calculations for heating air in a duct. Air flow and air pressure are related, but not tied together. Sometimes static pressure is given as Pascals (Pa). A total flow of 12 LPM is required to prevent the non-rebreathing bag from deflating. Example: you calculated an 524. In any case, if we can measure the forces, we can calculate the velocity of the air—which, of course, is the wind. For many practical reasons, from human comfort to industrial process design, the ability to determine and modify the properties of air is important. Actual Pressure. CFM = 400 delta T = 15*F BTU/hr = 1. Flow of # 1 Entering Branch (ACFM): Velocity Pressure of # 1 Entering Branch (inches Water): Flow of # 2 Entering Branch (ACFM): Velocity Pressure of # 2 Entering Branch (inches Water): Note: Sum of flows in branches # 1 and # 2 must equal Flow Rate in ACFM input above. Once we know how much heat a room needs to have supplied or removed, we can do a simple calculation to see how many cubic feet per minute of air flow we need. Q = flow in litre/s for liquids m 2 /h at 20°C and 1016 mbar for gases. 5L of air (every two crankshaft revolutions) is breathing at a ratio of 1. 91 CFM in. It allows you to calculate the flow or C v (flow coefficient) to make the relationship visible between the pressure drop (the difference in pressure between two points in a network transporting a liquid or gas) and the flow rate. (rounded to the nearest 100th) Win $100 towards teaching supplies! We want to see your websites and blogs. The Heat Exchanger Calculator is a program specially designed to predict the performance of the heat exchanger Model Number you choose based on the parameters you input. Cfm Calculation Formula. 79 in Hg For an example calculation, this slide lists the parameters of the test equipment, the dry gas meter calibration factor and the nozzle diameter. 1 inches of water (25 Pa). ): Round Duct Equivalent Diameter (in. 2,048 cubic foot room x 15 air exchanges = 30,720 cubic feet moved per hour. Compressor Terms you should know: Cubic Feet Per Minute (cfm) – Volumetric air flow rate. There are many ways to perform VE test with numerous calculators available on the web. Theory for this calculator can be found on pages 4-2 thru 4-5 in the 2009 edition of TP410. The equipment originally co has $20m, of which 80% has been depreciated. 0 Other Java. The variation between the temperature of the buildings in summer and the air in the cold air duct is 50 to 55. Actual Pressure. Compact single stage pressure regulators for applications where space is limited, such as inside a process tool. 12 Dimensionless F L 0. 21) + (Oxygen flow x 1. The Air Changes Formula. Fusion Fluid Equipment provides this tool for reference only. Professional calculations made easy. This requirement can be expressed by the following formula:. A compressor is going to operate under varying values of the variables affecting its performance. This formula is appropriate for bathrooms with one sink and one shower head. How to Calculate Cubic Feet Per Minute - Definition, Formula, Example Definition: Cubic Feet Per Minute (CFM) is a measurement for finding the air volume velocity and it is commonly used for measuring the air flow in heating or cooling diffuses. The C v calculator will calculate either C v or flow using the supplied additional parameters of fluid, inlet and outlet pressure, and fluid temperature. Example: The output flow of a pump spinning at a rate of 2000rpm. Home › Knowledge Base › Categories › Calculators › Orifice Size Calculator. Find the nozzle requirements for a given pressure or flow rate. Exhaust Pipe Size Estimate: A good section of straight pipe will flow about 115 CFM per. The “air” version of the sensible heat equation can be used in several ways: • If one knows the airflow, the entering air temperature (EAT) and the leaving air temperature (LAT); use the equation as stated above to calculate the amount of heat added to or taken from the air stream: Qair = 1. Your use of this website is. 4 lbs CO 2 per megawatt-hour (EPA 2018), which. The FiO2 and liter flow to the device will be provided in the given scenario. Their staff is efficient and quick to respond to all of our inquiries. Instead, we have procedures for taking load calculation results and getting the right piece of equipment that moves the right amount of air with the right number of BTUs. Also the required pipe diameter to carry a given flowrate with a maximum allowable head loss can be calculated. EXAMPLE: 3,400 tons of dry solids is processed in 24 hours in water with a specific gravity of 1. Drill more holes in the PS enclosure. The following calculations assume the compressor control strategy automatically turns off the second unit when it is not required. How to Calculate the Air Changes Per Hour (ACPH Formula): First of all, determine the velocity of the air below the HEPA filter in feet per minute. Basic Calculations for Fabric Duct The basis for fabric duct calculations is dependent on an internal air flow velocity of 1,500 feet per minute (FPM) @ 0. C V & FLOW CALCULATOR. 5 Q 1 ton = Q∆h/2670 cfm x static pressure (in. 0833 lb/ft 3. The air pressure differences are small in comparison to, say, the air pressure in the tire of a car. From a calculation viewpoint alone, the power calculation is particularly sensitive to the specification of mass flow rate, suction temperature and pressure, and discharge temperature and pressure. Calculate pressure in your float style flow-meter using this calculation. Excel templates can be downloaded to make venturi meter and orifice flow meter calculations in U. Our spray coverage calculator assists with estimating the number of spray nozzles required for a given spray angle, spray height based upon the coverage you require. 5 °F (10 to 13°C). Resist the temptation to step up to a larger duct in hopes of improving flow. Therefore, the most common approach is to use MAF. 36 for diagonal winds). Pipe Air Flow TEC-15 Flow of Air Through a Pipe PRIMARY PRESSURE - PSIG FLOW SCFM 2 1 10 20 30 40 50 60 70 80 90 100 150 200 250 3 4 5 6 7 8 9 10 20 30 40 50 60 70. Bernoulli's equation relates a moving fluid's pressure, density, speed, and height from Point 1 […]. Spray Nozzle Coverage Calculator. Another little known fact about compressed air from an end user’s point of view is that discharge pressure has a direct impact on flow. An acceptable temperature rise through the server is about 20°F. CUI Devices' air flow conversion calculator can be used to convert between common units for volume air flow and air velocity flowing past a point in a specified area of duct. Flow of # 1 Entering Branch (ACFM): Velocity Pressure of # 1 Entering Branch (inches Water): Flow of # 2 Entering Branch (ACFM): Velocity Pressure of # 2 Entering Branch (inches Water): Note: Sum of flows in branches # 1 and # 2 must equal Flow Rate in ACFM input above. MASS AIRFLOW (pph) = 12. Best practices suggest the distribution header should be sized to allow an air velocity not to exceed 30 ft/second. The velocity of the water is 3. Once we know how much heat a room needs to have supplied or removed, we can do a simple calculation to see how many cubic feet per minute of air flow we need. Flow (discharge) rate. So if we drop those values in for room 1 we get a volume flow rate of 0. The standard air pressure (atmospheric pressure) is 101325 Pa = 101. What good is all this? The multiplier (. To determine corrected flowrate: find the gas for which the meter is calibrated in the left column, move to the right to the gas that is being used. 696 PSIA, Normal = 0°C & 1. Parts Per Million (ppm) Converter. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are as essential for the working of basic functionalities of the website. 305 in •Measured – θ 120 min – ΔH 0. Excel spreadsheet formulas can be conveniently used to make calculation for differential pressure flow meters, like an orifice flow meter, a venturi meter, or a flow nozzle meter. 27 horsepower and use this for your hosepower to air flow calculation. Osborne Reynolds discovered that the flow condition depended upon the mean flow velocity, the diameter of the pipe and the kinematic viscosity of the fluid, formula 1. Flow is the compressor’s ability to continue performing a certain task. The Hydrant Flow Test Calculator measures the rated capacity at 20 psi of a fire hydrant. It is denser than water vapour, which has a molar mass of 0. HVAC design calculation used by professional mechanical engineers for Chiller Fans,Centrifugal Pumps,axial fans air,heat transfer for fluids. 746 (Power Factor) X Hours. 3208 / inside area of the pipe (sq ins) Circle area formulas: Area (sq ins) = π x r² where π (pi) = 3. * Required field. Increasing the CFM of the fuel delivery system is commonly done to increase horsepower. How the Air-Flow Calculator Works You don't need to know complex equations or spend hours with paper and pencil to figure out which negative air machine to buy. The table given below gives the discharge of air through an orifice in cu. air that is fed to the cylinders is highly important. 12 KWH electric rate and a 90% efficient electric motor. Louvers in this search are organized from the highest to lowest free area independent of model type. 95: Peak RPM: Enter peak RPM: Displacement in Cubic Inches: Engine displacement in. L = length of pipe, metres. This will equal an approximation of the flowrate of the gas being used. Flow calculation principles The principles of flow calculations are illustrated by the common orifice flow meter (see Figure 1). Then divide by the volume of the room in cubic feet: In plain English, we’re changing CFM into Cubic Feet per Hour (CFH). Then, select the corresponding CFM value from Table 2, or; For a rectangular port, calculate the area (multiply length times width, in inches). In other words water will flow approximately 68 times more units of volume through a hole than SAE10 lube if the lube is able to flow at all. Cubic Feet Per Minute or CFM’s. Air Flow Calculations CR-TEC reserves the right to change the contents without notice >Engineering Data CR-TEC www. The circuit of the cold air ducts is calculated for 100% of the necessary flow. water) is equal to about 25 Pascals (Pa). Bernoulli's equation relates a moving fluid's pressure, density, speed, and height from Point 1 […]. Energy to Heat Water. Learn more about the units used on this page. Do not remove copyright. Example: The output flow of a pump spinning at a rate of 2000rpm. p is pressure in KPA. It used to be performed by engineers with pen, paper, and slide rules,. Calculate the total volume of the vacuum system in cubic feet. 12 Dimensionless F L 0. KW Consumed by a Motor = Absorbed Power x Efficiency x Power Factor. For more information on the relationship of temperature, pressure, volume, mass, and molar weight, see Wikipedia's page on. \[\rho_a = \frac{1. Barometric Pressure. Available R-values will vary depending on insulation products selected. The methods used by HYSYS in calculating liquid density, vapour density, viscosity, thermal conductivity and surface tension are listed. com 1 Air Flow Calculations: Choked Flow Choked air flow will occur when the absolute pressure ratio of the outlet downstream pressure po to the upstream inlet pressure pi is 0. *Values are for discharge to standard atmospheric pressure. Heat Loss From An Insulated Pipe This Excel spreadsheet models heat loss from an insulated pipe. Air velocity can be calculated with the calculator below. The rule of thumb on the amount of vent space needed is approximately 1 sq. All you need to do is select the application from the dropdown, enter the size of the room and we will provide you with a general capacity range (m3/hr) that you should be looking to achieve from the extraction fan. The natural air flow. It calculates both rectangular and round duct dimensions. For example, if you only had to move the previously mentioned block a short distance every hour, a. All you need to do is select the application from the dropdown, enter the size of the room and we will provide you with a general capacity range (m3/hr) that you. v = velocity of air in feet per second (ft/sec) p = loss of pressure due to flow through the pipes in ounces per square inch (ounces/in 2) d = inside diameter of pipe in inches (in) L = length of pipe in feet (ft). 6301 | [email protected] CFM = 400 delta T = 15*F BTU/hr = 1. Frictional head loss and pressure drop can be calculated for given pipe flow rate, pipe diameter and length, pipe roughness, and fluid density and viscosity. Flow (discharge) rate. Design Calculations • Design Flow: 8,000 gal/day Design flow calculated from the Magnolia Utilities monthly water bill for the mobile home park. A fume hood or laminar flow cabinet needs constant air supply—just like the cleanroom. 187 x (20/15) x [540. KYPipe allows fire flow calculations to be made at hydrants, junctions or both. Use this same volume of air for the exhaust system, but then correct for thermal expansion (you need to know exhaust temps to figure things out). Use an hourly peaking factor of 4 for sizing the sedimentation facilities. I N S T R U C T I O N S. For example, a bathroom with a volume of 1000 cubic feet (28. P 1 + 1 atmosphere. Then based on the standards from ASHRAE /ISHRAE or from Buildings Codes one can easily. The above are representative flows for estimating purposes. In order for air to flow into, out of, or within a building, two requirements must be met: a hole or path must exist for the air to flow through, and there must be a driving force. This air will contain dust and dirt which accumulate on the surfaces of the electrical equipment. Determining Air Volume by Calibrated Resistance Manufacturers of air. This value is normally 14. Other common terms for this constant are K-constant or pickup gain. 92 inches of mercury. Tips When we talk about positioning the pitot tube 10 straight duct diameters upstream and 3 straight. The second model calculated air flow around and behind a lean 6ft runner moving at a pace of about 6 minutes 40 seconds per mile or walking at a leisurely 4km/h. Air Calculations and Conversions Guide - AWMA Iowa Chapter SULFUR DIOXIDE EMISSIONS DEFINITIONS: mw PPm DSCFM mg m3 ft3 SO, P hr R F min lb density air B WO molecular weight (air = 29. Here is the mathematical formula: V is in feet per minute (fpm) 4005 is a constant specific to this equation; DP is in inches water column (w. Learn more about the units used on this page. Look up your compressors maximum flow rate in the left column. Space Pressurization: Concept and Practice Infiltrating Air Flow P r e s s u r e D i f f e r e n c e x x O Based on need to control contaminants Not product spec. Available R-values will vary depending on insulation products selected. fan air flow calculation by input free area and air velocity, this airflow calculator is helpful for measuring flow at any fan just by knowing average air velocity on that area. Multiplying the 1. If circular, then A = π D 2 / 4. The C v calculator will calculate either C v or flow using the supplied additional parameters of fluid, inlet and outlet pressure, and fluid temperature. Sal introduces the notion of moving fluids and laminar flow.