Variable-Speed Blower

Related terms

• Vent Stack

  The piping admitting air so drains flow without siphoning traps, terminating through the roof. Adding fixtures often means new venting.

• UEF (Uniform Energy Factor)

  The standardized water-heater efficiency metric for comparing models; higher UEF means less energy per gallon delivered.

• Water Hammer / Arrestor

  The bang when fast-closing valves stop flow; an arrestor cushions it to protect pipes and joints.

• Two-Stage / Modulating

  Equipment that runs at partial capacity most of the time for efficiency and comfort, ramping up only on extreme days.

• Water Pressure / PRV

  Household pressure (ideally ~50–70 psi). A pressure-reducing valve protects fixtures where street pressure is too high.

• Tonnage

  AC/heat-pump cooling capacity (1 ton = 12,000 BTU/hr). Sized by a load calculation, not square footage rules of thumb — oversizing hurts…

• Water Service Line

  The pipe from the municipal main or well to the house. Old galvanized or lead service lines are often replaced during major remodels.

• Three-Way / Multi-Way Switch

  Switches controlling one fixture from two or more locations (stairs, long rooms). Adds wiring complexity in a remodel.