Calculation Methodology
Formula notes, assumptions, limits, and verification guidance for every I Love MEP calculator.
Cooling Load Estimator
Category: Mechanical / HVAC
Formula logic: Total kW = envelope + lighting + equipment + people + ventilation, with latent allowance and design margin. TR = kW / 3.517.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Duct Sizing & Velocity Checker
Category: Mechanical / HVAC
Formula logic: Velocity = airflow / duct area. Equivalent round diameter uses a rectangular duct approximation for planning comparison.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Airflow & CFM Calculator
Category: Mechanical / HVAC
Formula logic: Compares ACH-based airflow, occupant ventilation airflow, and cooling-ton airflow, then applies design margin to the governing value.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Chilled Water Pipe Sizing Tool
Category: Mechanical / HVAC
Formula logic: Flow is derived from cooling kW and chilled-water delta T. Velocity and friction head are estimated from selected pipe diameter and equivalent length.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Exhaust Fan Sizing Calculator
Category: Mechanical / HVAC
Formula logic: Compares room-volume ACH exhaust with fixture/equipment exhaust and applies the larger value plus margin.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Sprinkler Density & Coverage Planner
Category: Mechanical / Fire Fighting
Formula logic: Sprinkler demand = density x design area. Total demand adds hose allowance and margin. Water volume = demand x duration.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Fire Pump Sizing Calculator
Category: Mechanical / Fire Fighting
Formula logic: Pump flow combines sprinkler, hose, and hydrant demand. Pump head adds elevation, residual pressure, and pipe-loss pressure converted to meters.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Fire Hose Reel / Hydrant Demand Tool
Category: Mechanical / Fire Fighting
Formula logic: Base fire flow is hose reel plus hydrant connected flow. Simultaneous factor and duration produce demand and water volume.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Fire Water Tank Capacity Calculator
Category: Mechanical / Fire Fighting
Formula logic: Tank volume is based on total fire demand x duration minus accepted refill, divided by usable storage percentage.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
FM200 / Clean Agent Quantity Estimator
Category: Mechanical / Fire Fighting
Formula logic: Agent quantity = protected room volume x planning agent factor, then reserve allowance and cylinder count are estimated.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Cable Sizing & Voltage Drop Planner
Category: Electrical / Electrical Power
Formula logic: Current is calculated from kW, voltage, phase, and power factor. Voltage drop uses conductor resistance, route length, and selected cable size.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Electrical Load Schedule Builder
Category: Electrical / Electrical Power
Formula logic: Connected load is multiplied by demand factor, converted to kVA using power factor, then spare capacity is added.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Transformer Sizing & Spare Capacity Calculator
Category: Electrical / Electrical Power
Formula logic: Demand kW is converted to kVA, future spare is added, and the required kVA is divided by the preferred loading percentage.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Generator Sizing & Starting Load Planner
Category: Electrical / Electrical Power
Formula logic: Running kVA plus starting allowance is adjusted by diversity and spare capacity, then rounded to a practical generator class.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Power Factor Correction & Payback Calculator
Category: Electrical / Electrical Power
Formula logic: Required kVAR = kW x (tan acos current PF - tan acos target PF). kVA relief and simple payback are estimated.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Fire Alarm Battery Backup Calculator
Category: Electrical / Fire Alarm
Formula logic: Battery Ah = standby current x standby hours + alarm current x alarm duration, adjusted for derating and spare capacity.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Fire Alarm Loop Load Calculator
Category: Electrical / Fire Alarm
Formula logic: Loop usage is calculated from device counts, per-device current, loop current limit, and address capacity.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Fire Alarm DIP Switch Calculator
Category: Electrical / Fire Alarm
Formula logic: Device address is converted into binary switch weights for the selected fire alarm profile.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
CCTV Storage Calculator
Category: Electrical / ELV
Formula logic: Storage = camera count x bitrate x recording time x retention period, adjusted for RAID/formatting and spare allowance.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Data Rack Power & UPS Calculator
Category: Electrical / ELV
Formula logic: Rack load is converted to UPS kVA, heat output, and battery energy based on runtime and UPS power factor.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Access Control Door Hardware Planner
Category: Electrical / ELV
Formula logic: Door quantities are converted into controllers, readers, locks, power supply current, and backup battery Ah.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Water Demand Calculator
Category: Plumbing / Plumbing & Drainage
Formula logic: Daily demand and peak flow are estimated from occupancy, per-person consumption, fixture peak, diversity, and storage duration.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Pump Head Calculator
Category: Plumbing / Plumbing & Drainage
Formula logic: Total dynamic head adds static head, pressure head, and approximate friction head from pipe velocity and equivalent length.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Drainage Pipe Sizing Assistant
Category: Plumbing / Plumbing & Drainage
Formula logic: Fixture unit load is converted to a planning pipe diameter and checked against selected diameter and slope.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Water Tank Capacity Planner
Category: Plumbing / Plumbing & Drainage
Formula logic: Domestic reserve plus fire reserve is divided by usable storage percentage; refill rate is derived from gross volume and refill hours.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Hot Water Demand Calculator
Category: Plumbing / Plumbing & Drainage
Formula logic: Peak hot water demand is adjusted by storage factor; heating energy and recovery kW use water temperature rise.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Conduit Fill Calculator
Category: Electrical / Electrical Power
Formula logic: Conduit fill = total conductor area / conduit internal area. Spare same-size cables are estimated from remaining allowed area.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Short Circuit Current Calculator
Category: Electrical / Electrical Power
Formula logic: Transformer full-load current is divided by impedance percentage to estimate secondary fault current, then motor contribution is added.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Lighting Lux Calculator
Category: Electrical / Electrical Power
Formula logic: Required lumens = area x target lux / (utilization factor x maintenance factor). Fixture count = adjusted lumens / luminaire lumens.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Water Pipe Pressure Drop Calculator
Category: Plumbing / Plumbing & Drainage
Formula logic: Velocity is calculated from flow and pipe area. Friction head is estimated from equivalent length, velocity, and diameter.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Breaker Size Calculator
Category: Electrical / Electrical Power
Formula logic: Load current is calculated from kW, voltage, phase, and PF. Design current adds margin and rounds up to a standard breaker rating.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
kVA to Amps Calculator
Category: Electrical / Electrical Power
Formula logic: Single-phase amps = kVA x 1000 / voltage. Three-phase amps = kVA x 1000 / (sqrt(3) x voltage).
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Ampacity Derating Calculator
Category: Electrical / Electrical Power
Formula logic: Derated ampacity = base ampacity x temperature factor x grouping factor x installation factor.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Drainage Slope Calculator
Category: Plumbing / Plumbing & Drainage
Formula logic: Pipe fall = length x slope percentage. End invert = start invert - pipe fall. Gradient is expressed as 1:X.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.
Pump Horsepower Calculator
Category: Plumbing / Plumbing & Drainage
Formula logic: Hydraulic kW = density x gravity x flow x head. Shaft and motor power adjust for efficiency and motor margin.
Limits: Planning-level only. Verify with local code, authority requirements, manufacturer data, and project specifications.