Learn · Laurel County
HVAC Glossary
This HVAC glossary defines the terms London and Laurel County homeowners hear on service visits — SEER2, dual-fuel, static pressure, MERV, and more — in plain English. Use it beside our Learning Center guides and Act pages, not as a substitute for diagnosis. Leo Jones & Son Comfort Consultants will still translate any term on site since 1945.
Written and maintained by the Leo Jones & Son team · Last updated 2026-08-18. Authored for Laurel County homeowners by Leo Jones & Son, Inc. — a hometown, brand-agnostic HVAC company in London, KY since 1945. Incentive language is current-only (no expired federal 25C credits).
What do SEER2, HSPF2, and AFUE mean?
SEER2 — cooling efficiency metric under newer test conditions. HSPF2 — heat-pump heating efficiency metric. AFUE — furnace fuel efficiency. Higher generally means less energy for the same output when systems are comparable and installed correctly.
What HVAC system types do Laurel County homeowners hear about?
Split system — outdoor unit + indoor unit. Package unit — most components outdoors. Heat pump — heats and cools via refrigerant. Dual-fuel — heat pump + gas/propane furnace. Mini-split — ductless heat pump zone. Air handler — indoor blower cabinet for heat pumps/electric heat.
What do MERV, static pressure, and IAQ mean?
MERV — filter particle rating. Static pressure — resistance in the duct system. Return — air path back to the system. Supply — heated/cooled air into rooms. IAQ — indoor air quality (filtration, humidity, ventilation).
What do load calculation, commissioning, and PMA mean?
Load calculation — sizing based on home heat gains/losses. Commissioning — startup verification of charge, airflow, and controls. PMA — Preventive Maintenance Agreement (scheduled tune-ups). Balance point — outdoor temperature where dual-fuel switches heat sources.
What should you do when a proposal uses jargon you do not recognize?
See a term on a proposal you do not recognize? Call (606) 864-6105 and ask — we would rather explain than bury you in jargon.
Frequently asked questions about HVAC glossary in London and Laurel County
What does “matched system” mean?
Outdoor unit, indoor coil or air handler, and furnace (if any) tested together so ratings and warranties apply as published.
What is a line set?
The copper refrigerant piping connecting indoor and outdoor units. Condition and size matter for performance.
What is short cycling?
When equipment starts and stops too frequently — often from oversized equipment, control issues, or airflow problems. See /tips for symptom triage.
Where should I go after reading glossary terms?
Open the related Learning Center guides and Act pages linked from each topic — glossary definitions are starting points, not sizing advice.
Will you explain terms on a service visit?
Yes. Comfort Consultants translate SEER2, static pressure, and dual-fuel staging into what it means for your London-area home.
Ready for a local answer?
Leo Jones & Son has served Laurel County since 1945 — most major brands serviced, emergency service until 10:00 PM. Call or request service online.