Rectangular to rectangular duct calculator. HVAC Duct Quantity, Weight and Area Calculator .

Rectangular to rectangular duct calculator Your One Stop Shop for all your HVAC needs. Saves time: -faster than using a calculator -improved accuracy -no multipliers or trig formulas to remember -redu… Area = Surface area of duct in square feet. Simple calculator for calculating the area of a rectangular duct online. Nov 15, 2023 · The Duct Circumference Calculator is versatile and can calculate the circumference for various duct shapes, including rectangular, circular, or semi-circular ducts. Use it in one of two ways; either enter the duct size to find the equivalent CFM, or input the CFM to find the right size of rectangular, round or flex duct. L = Length of duct in feet. One side uses English Use the on-line duct sizing tool below, please be patient as the rectangular Ductulator loads. You’ll get recommendations in the form of diameter for circular ducts and the dimensions for rectangular-shaped ducts. ft) Nov 21, 2022 · 1) units of height and width of a duct. a = length one side of duct, in. 5) * 12. App Description. Using the duct area calculation calculator, you can accurately calculate the cross-sectional area of the duct and carry out an engineering calculation that will ensure To make things easier, you will find the FPS To CFM Calculator (2nd Calc) for rectangular ducts (you insert FPS, duct width, and duct height, and the calculator will determine CFM). General sizing tip; It is common to select duct sizes with velocities between 3 m/s and 6 m/s or limit the pressure loss per meter of duct to 1 Pa. 3 Rectangular Duct No. Formula for calculating Aug 1, 2023 · Duct Transition Pressure Drop Calculator Duct Transition Pressure Drop Calculator Duct Width (inches): Duct Height (inches): Airflow Rate (CFM): Duct Length (feet): Duct Material: Galvanized SteelAluminum Air Temperature (°F): Calculate Pressure Drop Duct Type Pressure Drop (inches of water) Straight Duct Transition Duct FAQs GEGCalculatorsGEG Calculators is a comprehensive online platform Online calculator to calculate the area of a rectangular duct. Rectangular. 2. Hydraulic diameter for rectangular duct The Hydraulic Diameter in rectangular pipe is calculated thanks to the following formula : D H =(2. For Imperial unit, let’s say the duct length is 12″ (1 ft), the duct area of the 40″ by 4″ rectangular duct is: Duct Area = (Duct Width x Duct Length x 2) + (Duct Height x Duct Length x 2) Jan 4, 2025 · Duct Volume Calculator help you quickly and accurately calculate the volume of air ducts. b = length adjacent side of duct, in. You can calculate the required size of the duct with this formula: Area (in square inches) = CFM × 144 ÷ Velocity (FPM) Once you have the area, you can calculate the width and height of the rectangular duct based on the available space and layout. The Equivalent Diameter when Flow in Rectangular Duct formula is defined as the ratio of 4 multiply by length and breadth of rectangle to the 2 multiply by summation of length and breadth of rectangle and is represented as D e = (4*L*B)/(2*(L+B)) or Equivalent Diameter = (4*Length of Rectangular Section*Breadth of Rectangle)/(2*(Length of Rectangular Section+Breadth of Rectangle)). [ ] Step 4: Review Duct Sizing; The calculator will provide you with recommended duct sizes and layouts. Sep 30, 2023 · The weight of a rectangular duct depends on its dimensions, material, and thickness. The Darcy friction factor can be calculated from the Moody diagram using either the Hagen-Poiseuille laminar flow equation, the original Colebrook White equation or the modified Colebrook White equation. 5 kilograms per linear meter. Calculate with confidence using our HVAC duct Calculator, Air Duct Calculate the equivalent size of spiral ducting when you have only been given the rectangular duct dimension (it works the other way also) Open the ES Calculator System Pressure Calculator Oct 3, 2024 · The formula for calculating duct weight (DW) is: \[ DW = \left(2 \times (H + W)\right) \times L \times T \times D \] Where: DW is the Duct Weight (lbs) H is the duct height (in) W is the duct width (in) L is the duct length (in) T is the duct thickness (in) D is the duct density (lbs/in³), which for aluminum is typically 0. height. D = Diameter of duct in inches. For various equivalent diameters, approximate rectangular duct dimensions can be estimated. ft)CFM=Airflow Velocity (FPM)×Cross-sectional Area (sq. Calculate single phase gas flow in a rectangular duct. There are a few other important factors to consider when using a free HVAC duct sizing calculator to determine HVAC duct dimensions and sizing, such as ducting material type. 1. For each new calculation a unique conversion scale will be generated for the range of volumetric flow rates and flow speeds for the length and width specified. Where: Area = Surface area of duct in square feet. when the quantity take off is completed, take 10% extra of duct this will resolve the quantity assumption . First, let’s look at the formula that translates rectangular duct size to round duct size. Thus, by entering these parameters, the Ductulator then helps determine the optimal dimensions for both a round and a rectangular duct to ensure efficient airflow and minimal pressure drops. Air velocity can be calculated with the calculator The equivalent diameter is the diameter of a circular duct or pipe that for equal flow gives the same pressure loss or resistance as an equivalent rectangular duct or pipe. This round duct size can handle 200 CFM airflow. It provides a simplified representation of the rectangular duct’s behavior for certain calculations. 5499 Brooks St Montclair CA 91763 Phone: +1 909 635 1335 Email: sales@pacificduct. com Flex duct = . Oct 15, 2023 · How does the equivalent diameter of a duct relate to a rectangular duct section? The equivalent diameter of a duct is an imaginary circular duct that has the same hydraulic characteristics (flow and resistance) as the rectangular duct. 07. 833 sq ft. It explains how to calculate the area of straight ducts, elbows, reducing elbows, reducers, drop necks, end caps, offsets, transitions, and reducing and equal tees. We will Jan 19, 2000 · Sheet Metal Duct Friction Loss Calculator. 1-inch round diameter duct. If necessary, enter the cost per unit or linear meter. These estimations aid in HVAC system design and airflow calculations Convert Round Duct Size to Rectangular Duct Size for equivelant airflow. The formula used is 2 * pow((ductArea / 3. Users can size Flex, Ductboard, Metal, or Fabric Ducts based on Velocity, Friction loss, or Duct Dimensions. A round shape results in lower pressure drops and less fan horsepower to move the air and, consequently, smaller equipment. H = Height of duct in inches Free HVAC Duct Sizing - in SI/Metric or US/Imperial units. ) Duct Size Friction Loss Rate; Sizing duct work on your own can be a tedious and complicated task. 07" on most metal duct calculators Duct Size Calculate Rectangular Duct Equivalent Diameter Kindly enter the preferred width and height of your duct to calculate the equivalent diameter: How to Calculate the Equivalent Diameter of a Rectangular Duct Based on the duct design chapter of the ASHRAE Handbook of Fundamentals, the equivalent diameter of a rectangular duct is calculated using the below formula: This tool will calculate the velocity in any units from the specified volumetric flow rate of a substance flowing through a rectangular duct of a defined width and height. As a rough estimate, a standard rectangular duct measuring 100×50 mm and made of sheet metal with a thickness of 1 mm may weigh around 0. Rectangular duct is rounded up to the nearest 1/4 inch. The Hydraulic Diameter of a fully filled Rectangular Duct calculator compute the hydraulic diameter of a fully filled rectangular duct based on its dimensions. 047 : inWg/100ft D e = circular duct diameter for equal length, fluid resistance, and airflow, in. These calculations are divided in four areas: 1. Use a measuring tape that measures in inches. Aug 1, 2023 · How do you calculate pressure drop in a rectangular duct? Pressure drop in a rectangular duct can be calculated using the Darcy-Weisbach equation, which considers factors such as duct dimensions, air velocity, density, friction factor, and duct length. Square footage of each individual room in your home. l)/(l+e) e=Height of the flow section (m) Often used in tight spaces, such as in walls and ceilings, rectangular duct allows you to select larger sizes without increasing duct height. The head loss calculator below is based on formula (1) : b = height/width of the duct (m, ft) Related Mobile Apps from The EngineeringToolBox. Click here to use the Ductulator. 05" on most metal duct calculator Round metal pipe = . Select the duct material from the drop-down list (most duct sizing tools are typically based on galvanised steel ducting by default) Enter the air flowrate in litres/second (can change to cubic metres/second by use of drop-down to the right of the input) Free online ductulator for sizing of HVAC ducts. 10 pressure drop per 100’ EL) CFM Round (No. This tool is essential for HVAC professionals and anyone involved in designing or installing ductwork, ensuring efficient airflow and optimal system performance. Jul 26, 2023 · How do you calculate CFM for a rectangular duct? To calculate CFM for a rectangular duct, you’ll need to know the airflow velocity (in feet per minute) and the cross-sectional area of the duct (in square feet). Pressure vs. Step 4: Determine Duct Size FPM (Rectangular Ducts) = CFM × 144 / (Duct Width (Inches) × Duct Height (Inches)) Basically, with rectangular ducts, we need to first multiply CFM by 144 (for inches to feet conversion), and then divide the product by the product of duct width and duct height (both in inches), to adequately convert CFM to FPM. 14159), 0. Diameter converter, which allows converting circular to equivalent rectangular ducts. 5 m) (0. Cubic feet per minute calculations (explained below. Optimize airflow, reduce energy costs, and enhance system efficiency with precise calculations tailored for commercial, industrial, and pharmaceutical applications. The area of rectangular ducts is calculated as x*y where x and y and the length of the sides of the ducts. * Indicates Required Field Can I Paint Spiral Duct? Duct Entry Configuration (must choose one): Rectangular Ducts (chose up to three different elbow types): Show me what these rectangular elbows look like ; Our online duct cross-section calculator helps to calculate these parameters for various types of ventilation systems, whether it is a round duct or a rectangular vent channel. You can use the below formula to calculate the volume of a rectangular duct. Convert Round duct to Rectangular Equivalent . Convert rectangular and oval duct geometry to a equivalent circular diameter - online calculator with imperial and SI-units. You may need to input additional parameters, such as the type of duct (round, rectangular) and the layout (straight, branched). Equivalent Round Duct Diameter for Rectangular Opening. v m = (1 m 3 /s) / ((0. Hydraulic diameter for rectangular ducts can be calculated as. 100 200 300 400 500 600 700 800 900 1000 100. W = Width of duct in inches. The Excel sheet above calculate the HVAC duct Area: Duct Surface Area; Gauge The document provides steps to calculate the area of various rectangular and square HVAC duct fittings. d h = hydraulic diameter (mm, in) a = width of the duct (mm, in) b = height of the duct (mm, in) Hydraulic diameter of some common rectangular ducts: [ ] Step 3: Input Data into Calculator; Enter the measurements and airflow requirements into the duct calculator. However, for calculating the volume of a rectangular duct, the formula is slightly different. Feb 23, 2015 · Measure one side of the duct from top to bottom, then measure the bottom of the duct from left to right, if the duct is square or rectangular. 01745rcl\) a, b - side length; r - radius; c - center angle Nov 7, 2022 · Example: 10-inch round duct has a radius of 5 inches. PRO's duct calculator will help you estimate the required duct size of the ventilation system for quality air exchange in the room. To calculate the duct area, you first need to have a duct length. Note: Linear pressure loss is based on an absolute Rectangle Pipe Weight Calculator / Online Rectangle Pipes Weight Calculator, Weight Calculator/ Pipe Tube Weight Calculator / stainless steel pipe weight calculator/rectangular hollow section weight calculation formula/structural steel weight calculator/rectangular pipe weight/Hollow structural sections - rectangular Sep 30, 2023 · To calculate the volume of a duct, you can use the formula for the volume of a rectangular duct: Volume (m³) = Width (m) x Height (m) x Length (m) For a round duct, use the formula for the volume of a cylinder: The Digitized Ductulator is a free online calculator for sizing HVAC ducts. KALK. Example: 10×12-inch rectangular duct has a cross-section of 10*12 = 120 sq inches or 0. After you have input both values, clicking on the “Calculate Duct Size” button will give you the results for recommended duct sizes. It will also convert rectangular to flat oval. Specify the quantity of elements in units or linear meters. By multiplying this air velocity by the air flow rate across the cross-sectional area of a duct, you can determine the volume of air flowing through the duct per unit of time. Side А Pacific Duct Inc. May 17, 2023 · What size round duct do you need to replace the 6×7 inch rectangular duct? Using the rectangular to round duct transformation formula will tell you that you need a 7. Enter the Length (inches) and Width (inches) of the Rectangular Duct. Hydraulic Diameter App - free apps for offline use on mobile devices. Note: A flexible duct, type spiral wire core helix, not completely stretched, is considered. If a rectangular duct has a width of 10 inches, a height of 8 inches, a bend radius of 6 inches, and bends at an angle of 90 degrees with 2 ducts, the formula will be: A = (10 + 8) ∗ 2 ∗ [(6 + 10/2) ∗ π ∗ (90/180)] ∗ 2 Oct 27, 2023 · If you want to determine the volume of a rectangular duct, you can apply the same steps as mentioned earlier. Step 2 Jul 31, 2024 · What you will need to know to calculate ductwork sizing for your home: Square footage of your home. 073: inWg/100ft: Rectangular duct(mm): "x " 4500: FPM: 0. 5 sq inches or 0. You can also create reports that document projected performance and a bill of materials. Δh = friction or head loss (inches water gauge/100 ft of duct) d e = equivalent duct diameter (inches) q = air volume flow - (cfm - cubic feet per minute) For rectangular ducts the equivalent diameter must be calculated. DACKA is a rectangular duct attenuator in galvanized steel* with splitters filled with Acutec® attenuation material. The Moody diagram can be used for rectangular ducts if the R Jun 5, 2017 · The Eastern Sheet Metal Equivalent Round Duct Calculator app allows sheet metal contractors and installers, as well as heating, ventilation and air-conditioning (HVAC) engineers and contractors, to convert the dimensions of rectangular and flat oval ducts to round. As a rough approximation, a round duct with a diameter of 6 inches might correspond to a rectangular duct of 8×4 inches, but these conversions vary based on project requirements. For instance, an equivalent diameter of 8 inches might correspond to an approximate rectangular duct of 5. Example. Equivalent Diameter: Diameter of a round duct that equates to the same pressure loss as the corresponding rectangular duct. 09 to . This essential calculation aids in optimizing airflow, ensuring efficient ventilation systems, and maintaining optimal indoor air quality. 75 inches by 5. Jan 12, 2025 · Use Envigaurd's advanced duct size calculator online for free to accurately determine the right duct sizes for your HVAC system. Side 1: inches Side 2: inches . From rectangular to circular. 14159265. The velocity should typically fall within a recommended range to minimize noise and pressure drop. This tells you the length of the perimeter of the duct. 1 lbs/in³ Heat Loss from Ducts Equations and Calculator ; Convert Rectangular Ducts to Round Sizes to Round Sizes Formula and Calculator ; Duct Roughness Factors Table ; Ventilation Duct Stack Pressure Review, Formulas and Calculator ; Minimum Duct Insulation R-Value ; Round Duct Heat Transfer Coefficient Wall Temperature Heat Transfer Equation and The Duct Size Calculator helps users determine optimal duct dimensions and performance metrics such as duct area, round duct diameter, rectangular duct dimensions, equivalent diameter, and friction loss based on specified airflow rate, air velocity, duct shape, and aspect ratio. Sep 17, 2023 · Converting round to rectangular duct sizes depends on specific design factors. Are there any specific units required for using the calculator? Gas Rectangular Duct Pressure Loss . Most old calculators (including cardbox ones) will only use the given velocity to calculate the diameter of the round duct then it calculates the static pressure loss for the round duct and uses that static pressure to calculate the rectangular duct dimensions which is not the case here so getting more precise velocity output. Duct and fittings have interconnecting ends that lock together with brackets. Click the "Calculate" button to get the final result. Formula Yes, our air duct velocity calculator is designed to accommodate various duct shapes, including round and rectangular ducts. A Ductulator is a tool used to calculate the appropriate size of HVAC ducts based on factors like airflow rate, velocity, and friction loss. This is a handy tool when deciding what size duct you want to use for your application. Unless within 2%, the diameter is rounded up to the nearest inch. Explore more helpful tools at The Chill Brothers to optimize your HVAC system. This Ductulator uses the Colebrook equation to calculate the smallest duct size acceptable for the selected friction rate and duct type that stays within the selected ACCA Manual D recommended velocities. Easy to Use Online Ductulator / Duct Size Calculator. Pi = 3. The round duct size gives the size in diameter; The rectangular duct options give the width and height. The calculator below is based on formula (4) an can be used to calculate the hydraulic diameter of rectangular duct or tube. Read Round Duct Diameter (inches) and Friction Loss Per 100' of duct (inches of water). Select the type of duct element you want to calculate. Use the right size duct. Convert Volume Flow Rate; Convert Duct Types to round, oval, or rectangular; Perform pressure, stiffener spacing, and gauge calculations; Calculate Thermal Data Feb 19, 2024 · 36″ x 10″ Rectangular duct; 30″ x 12″ Rectangular duct; For round solid duct we use a friction rate of 0. Automatically, the ‘B’ marker will move until showing the width of the rectangular duct. Calculate the equivalent size of spiral ducting when you have only been given the rectangular duct dimension (it works the other way also) Open the ES Calculator System Pressure Calculator new or existing round, rectangular, or flat oval supply duct systems. Related: Convert Flat Oval Ducts to Round Sizes Formula and Calculator; Heat Gain or Loss HVAC Duct ASHRAE Formula and Calculator; Duct Design Air Flow Velocities; Residential Duct Systems Design Air Flow Conversion Calculator Description Air velocity, which represents the distance traveled per unit of time, is commonly expressed in Linear Feet per Minute (LFM). Users can input the dimensions of their specific duct shape to obtain accurate velocity calculations. 4. what size duct do i need for 2500 cfm? For an airflow of 2500 CFM then your options are: 36″ x 12″ Rectangular duct; For rectangular duct we use a friction rate of 0. For technical drawings and 3-D models, click on a part number. Round duct: "Ø: 573: FPM: 0. Rectangular to Circulate Duct/Tube Hydraulic Diameter Calculator. Complete information highlighted in yellow. To supplement the calculator, we have also calculated FPS to CFM for 4×10, 6×12, 8×12, and 12×12 ducts from 1 FPS to 500 FPS . Rectangular: Area = (W * 2 + H * 2) / 12 * L. Set the duct height by moving ‘A’ marker on the bar or introducing the desired value into the corresponding cell. 545 sq ft. Do you plan on installing an HVAC rectangular duct or round duct? Nov 11, 2023 · The Duct Area Calculator is a powerful tool designed to help individuals and professionals in the HVAC industry determine the cross-sectional area of rectangular and circular ducts. Rectangular Duct Dimensions ( mm ) Width. This calculator can be used to calculate the weight of the tube, the length of the product by weight, and the calculation of the cost of products by weight and length. Round duct (mm): "Ø: 573: FPM: 0. 5 m duct with air flow 1 m 3 /s can be calculated as. Whether you are working with rectangular or circular ducts, simply input the necessary dimensions, and the calculator will provide the total volume. e. The Trane Ductulator - Duct Sizing Calculator is a hand held rotating calculator used for sizing supply and return duct systems using the equal friction design method. Diameter converter, which converts circular diameters to equivalent rectangular ducts. 5 m x 0. This may be needed to calculate the cost of the purchased batch of products from rectangular tubes, as well as the weight and dimensions for transportation. These calculations are divided into four areas: 1. head; Air Ducts Friction Loss Calculator - Imperial Units. If using the velocity method, calculate the required air velocity in the duct based on the airflow rate and the cross-sectional area of the duct. Activate the block of ‘A’ marker with the lock. Acutec® is a hygienic and washable polyester absorption material with high airflow and shock resistant non-woven fleece finishing and no loose fibres. 810 Cold air boot, collar, duct 45- 65’ EL AIR FLOW DYNAMICS & DUCT SIZING REFERENCE GUIDE SUPPLY OR RETURN DUCT SIZE/CAPACITY (. Step3: Calculate Duct Velocity. Rectangular Duct Dimensions: If a rectangular duct is chosen, the calculator provides both width and height dimensions. 75 inches. Rectangular Air Ducts - Velocity Diagram Velocity diagram for rectangular air ducts - metric units. Rectangular Ducts - Dimensions Commonly used metric dimensions for rectangular air ducts in ventilation systems. Rectangular elbow area calculation \(S= \frac {r π c°}{180°} \times 2(a+b)=0. Round Duct Diameter: If a round duct is selected, this measurement is computed and displayed in inches, rounded to one decimal place. What is the pressure loss per 100 feet of ducts? Sep 17, 2023 · The equivalent diameter represents the circular cross-section equivalent to a rectangular duct. Volume of Rectangular Duct : Length * Width(side A) * Height(side B) The S&P duct calculator allows three different calculations to be carried out quickly and with ease. Transition Calculator is useful for Generating Flat Pattern Layout or Fabrication Layout of all types of transition shapes such as rectangular to round, square to round, round to rectangular, round to square, pyramid and truncated pyramid transitions. 06, for rectangular we use 0. 14*5 2 = 78. The formula is: CFM=Airflow Velocity (FPM)×Cross-sectional Area (sq. Converts a rectangular size to the appropriate round size or the available ESM flat oval size. d m = diameter of duct (m) a m = width of duct (m) b m = width of duct (m) Example - Air Flow Velocity in a Duct. Aug 22, 2015 · Reynold Number can be calculated using Re=VD/Vk Since the Volumetric flow rate is given Q=200 gal/sec and the area (4x8)ft² we can get the Velocity V Q=AV Sep 28, 2024 · Click the “Calculate” button to find the total duct bend area. Enter the dimensions of the element according to the provided diagrams (for round and rectangular elements). So, let’s do an example. The velocity in a rectangular 0. Includes scales for friction loss per unit length, air volume, air velocity, round duct diameter, and rectangular duct diameters. SL) Rectangular (TD) 50 5” 8 x 6 75 5” 8 x 6 100 6” 8 x 6 3½ x 10 (110) 125 6” 8 x 6 3½ x 12 (140) 150 7” 8 x 6 3½ x 14 (160) 175 7” 8 x 6 200 This script provides the user flexibility to choose if the user wants to calculate duct weight for all rectangular ducts or just for the selected ducts. The S&P duct calculator allows three different calculations to be carried out quickly and with ease. Enter Duct Airflow (CFM), Duct Velocity (FPM), Duct Length and the number of bends. 2) scale of the drawing. 12 = Inches per foot. VariTrane Duct Designer consists of three applications: Duct Configurator to model and size duct supply systems, Ductulator™ to size system components and determine Jun 3, 2018 · To calculate the rectangular duct area, we need height, width and length. Transition Calculator provide complete solution to Transitions Fabrication Layout Markings. 06" on most metal duct calculators Rectangular sheet metal duct = . Its cross-section is calculated as 3. Select the duct material from the drop-down list (most duct sizing tools are typically based on galvanised steel ducting by default) Enter the air flowrate in cubic feet per minute (CFM) Enter an internal duct size in inches (this must be limited to a maximum aspect ratio of 5:1 for the results to be valid) Other Details for Duct Sizing Calculator. Additionally, by offering flexibility in duct shape options such as round equivalent and rectangular equivalent diameter, the calculator ensures that users can accurately size ductwork for a wide range of HVAC applications, from residential homes to commercial buildings. Mar 26, 2024 · Duct Area Calculation. HVAC Duct Quantity, Weight and Area Calculator. d h = 2 a b / (a + b) (1) where. 5 m)) = 4 (m/s) Air Flow Velocity Calculator - SI Units. ‎Easy Offset is an easy to use program designed for the HVAC industry that calculates cut joints, elbow centerlines, and overall lengths for offsets of any angle. For each fitting type, it provides illustrations of the dimensions and formulas to calculate the fitting area. Convert Rectangular duct to Round Equivalent . 07 Nov 6, 2024 · How to read the results of The Ductwork Sizing Calculator: The output from the calculator will give you up to 4 duct size options to choose from: 1 round size and up to 3 rectangular size options. The user can also choose the material of the duct and the Dynamo will do the rest. To calculate the rectangular duct area, we need Duct Area Calculation excel sheet, height, width and length, take 10% extra of duct this will resolve the quantity assumption. Read computed values for Equivalent Round Duct Diameter (inches). 073: inWg/100ft: Rectangular duct: "x " 4500 Rectangular Duct Formula: For rectangular ducts, the area of the duct is used. Use the calculator to add these two measurements together and multiply by two. The document was Flexible Duct Size D/L[mm] D [mm] L [mm] Quantity [pcs] Flexible Duct Lateral Area / Free Area / Perimeter L Area [m²] F Area [m²] P[mm] Flexible Duct Options: Insulation Acoustic Insulation. Duct System Design Guide First Edition ©2003 McGill AirFlow Corporation McGill AirFlow Corporation One Mission Park Groveport, Ohio 43125 1. ubh ciov dqdrf enooes pwofcf mrqo vbzfm wkiiy rpgvvw zxmi