Reference
Glossary
Canonical definitions for trade terms used across Eco guides — linked to Learn, Evaluate, and service pages for consistent terminology.
How to use this glossary
Use these definitions to decode estimates, compare options, and understand what matters in your home before you book. Each term connects to Learn and Evaluate guides so you can move from terminology to real-world decisions.
AFUE
Annual Fuel Utilization Efficiency — measures furnace efficiency as a percentage of fuel converted t…
Define → Heating & AirSEER2 / HSPF2
Seasonal efficiency ratings for cooling (SEER2) and heating (HSPF2) under updated DOE test procedure…
Define → Heating & AirIAQ (Indoor Air Quality)
The condition of the air inside a building — particles (PM2.5), VOCs, biologicals, radon — controlle…
Define → Heating & AirStatic pressure
The resistance an HVAC blower pushes against to move air — filters, coil, ducts, and registers combi…
Define → Heating & AirMERV
Minimum Efficiency Reporting Value — the ASHRAE 1–16 scale for how reliably a filter captures partic…
Define → Heating & AirHeat pump
HVAC equipment that moves heat rather than generating it — provides efficient heating and cooling; c…
Define → Heating & AirDuctless mini-split
Zone HVAC system with outdoor compressor and indoor head(s) — no ductwork; common for additions, ADU…
Define → Heating & AirManual J load calculation
ACCA standard for sizing HVAC equipment to a home's calculated heat loss and gain — required for pro…
Define → Multi-tradePSE Rebates
Puget Sound Energy incentive programs for efficient heat pumps, ductless systems, and water heaters …
Define → Multi-tradeHEAR program
Home Electrification and Appliance Rebates — federal/state program layer for income-qualified effici…
Define → PlumbingTank vs tankless vs heat-pump water heater
Three common water heater types — storage tank (lowest upfront), tankless on-demand (long life), hyb…
Define → PlumbingRepipe
Replacement of supply piping throughout a home — often from failing galvanized or polybutylene to PE…
Define → PlumbingSlab leak
Water leak in pipes embedded in concrete foundation — detected electronically before targeted repair…
Define → PlumbingHydro-jetting
High-pressure water cleaning of drain and sewer pipe walls — scours grease and scale beyond what sna…
Define → ElectricalGFCI / AFCI
Ground-fault and arc-fault circuit protection — shock protection in wet areas (GFCI) and fire preven…
Define → ElectricalPanel upgrade
Replacement or upsizing of the main electrical panel and service — common when adding EV, heat pump,…
Define → ElectricalKnob-and-tube wiring
Early 1900s wiring method using ceramic knobs — ungrounded; often requires replacement in active cir…
Define → ElectricalDedicated circuit
A breaker and wire run serving exactly one appliance or room — required by the NEC for ranges, dryer…
Define → ElectricalElectrical load calculation
The NEC Article 220 math that determines whether your electrical service can carry your home's appli…
Define → ElectricalEV charging levels (Level 1 vs Level 2)
Level 1 charges from a standard 120V outlet at 3–5 miles of range per hour; Level 2 uses a dedicated…
Define → ElectricalWhole-home surge protection
A panel-mounted device (SPD) that clamps voltage spikes from grid switching, storms, and large motor…
Define → ElectricalAluminum branch wiring
Single-strand aluminum wiring installed in many 1965–1975 homes — its connections loosen and oxidize…
Define → PlumbingHeat pump water heater (HPWH)
A water heater that moves heat from surrounding air into the tank instead of generating it — using r…
Define → PlumbingSewer scope (camera inspection)
A waterproof camera run through your sewer line to document its actual condition — roots, bellies, o…
Define → PlumbingPRV (pressure reducing valve)
The bell-shaped valve that drops incoming street water pressure to a safe household level — code req…
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