Tools › Building Systems

Building Systems

22 tools in 11 sections. Each tool page shows the method with the numbers substituted, its references and the published examples it reproduces.

HVAC Loads 1

  • Room Heating and Cooling Load Design cooling and heating load of a room or zone by the component method: conduction through walls, roof and glass with the cooling-load temperature difference of each…

Ducts and Airflow 4

  • Duct Sizing Velocity, friction loss and fitting loss of each segment of a duct run and the total static pressure the fan must supply, by the Darcy equation with the Colebrook…
  • Fitting Loss Coefficients The pressure loss of the fittings in a duct run, each from a catalog of loss coefficients of the common elbows, transitions, entries, exits, branches, dampers and…
  • Duct Leakage Leakage airflow of a duct system from its surface area, the static pressure in it and the SMACNA leakage class of its seal level: Q = C_L p^0.65 per unit of surface, the…
  • Static Regain Sizing Sizing of a supply trunk by the static-regain method: after each takeoff the trunk velocity is reduced so that the regain of static pressure from the lower velocity…

Psychrometrics 3

  • Psychrometric Calculator The full state of moist air from its dry-bulb temperature and one other property (relative humidity, wet-bulb temperature, dew point or humidity ratio) at the pressure…
  • Mixing and Coil Process The two processes that make up an air handler: adiabatic mixing of a return-air stream with an outdoor-air stream, and the coil that takes the mixture to its leaving…
  • Humidification Water Water or steam needed to take an airflow from its entering state to a target humidity, by the two ways it is done: steam injection, which adds moisture at nearly…

HVAC Equipment 2

  • Fan Operating Point Where a fan will run on a given system: the catalog fan curve (airflow against pressure at the test speed) is scaled to the operating speed by the fan laws, the system…
  • Hydronic Pipe Sizing Velocity, friction loss and pump head for the pipe segments of a hydronic (chilled- or hot-water) circuit: each segment takes a flow, a length, a nominal Schedule 40…

Ventilation and Air Quality 2

  • Ventilation Rate Minimum outdoor airflow of a space by the ventilation rate procedure of ASHRAE Standard 62.1: the breathing-zone rate is the people component R_p times the occupants…
  • Industrial Ventilation and Exhaust Hoods Local exhaust system design from the hood to the stack: the exhaust flow of each hood from the published capture-velocity relations (plain and flanged openings, slots,…

Energy 1

  • Energy Savings and Payback Four tools for the energy auditor, each switched on by a checkbox. Weather normalization fits monthly bills with the ASHRAE Inverse Modeling Toolkit change-point models…

Plumbing 1

  • Plumbing Pipe Sizing Water-supply demand and pipe size, drainage stack, vent and building drain of a building from first principles: Hunter's probability method (NBS BMS 65, 1940) computed…

Fire Protection 2

  • Sprinkler Hydraulics Hydraulic calculation of a tree or gridded sprinkler system by the node method of a calculation sheet: the most remote head at its minimum pressure, Q = K√p at every…
  • Fire Dynamics Calculations Compartment and pool-fire dynamics by the closed-form methods of the NRC handbook NUREG-1805, Fire Dynamics Tools, as revised in its Supplement 1: hot gas layer…

Lighting and Electrical 3

  • Lighting and Circuit Sizing Two building-electrical calculations under one select. Lighting by the lumen method: the room cavity ratios, the effective reflectances of the ceiling and floor…
  • Voltage Drop and Short Circuit Three building-electrical calculations under one select. Voltage drop of a single-phase or three-phase feeder or branch circuit: conductor resistance from the NBS copper…
  • Generator and UPS Sizing Three sizing calculations of a building's backup power under one select. Generator sizing from a load schedule: running kW and kVA of resistive, motor, UPS, lighting,…

Controls and Commissioning 1

  • Control Loop Tuning PID tuning of a building-services control loop from a first-order-plus-dead-time (FOPDT) or second-order (SOPDT) process model, or from a pasted open-loop step response…

Codes and Compliance 2

  • Envelope UA Compliance Building-envelope compliance by the total-UA trade-off used by the DOE REScheck and COMcheck programs: the sum of U-factor times area of every proposed assembly against…
  • Occupant Load and Egress Capacity Occupant load of every space from its floor area and an occupant-load factor (entered, with the use selection supplying a sourced default: UFC 3-600-01 Table 10-1 and…