HVAC guides, written by techs — for techs.

16 guides

Advanced Diagnostics

Senior-tech troubleshooting: localizing refrigerant restrictions, reading a dead system, measured-vs-expected superheat, and the gotchas that separate a diagnostician from a parts-changer.

6 guides

Airflow & Ductwork

CFM per ton, blower speed, static pressure, filter pressure drop and duct sizing — how to get the airflow a system actually needs before you ever touch the charge.

5 guides

Codes & Safety

Combustion air, venting clearances, gas piping and electrical disconnects explained by code section number — the safety rules every install and service call has to meet.

5 guides

Commercial Refrigeration

Racks, cases, walk-ins and defrost on commercial refrigeration — superheat, subcooling and controls in the low- and medium-temp world.

12 guides

Commercial Refrigeration Deep Dives

Advanced commercial refrigeration — rack systems, subcooling strategies, defrost design and controls for the serious refrigeration tech.

5 guides

Commercial Rooftop Units (RTU)

Packaged rooftop units: economizers, multi-stage, belt-drive blowers, 3-phase basics and rooftop preventive maintenance.

16 guides

Components Reference

What each HVAC component does and how to test it — capacitors, contactors, motors, boards, valves and sensors, explained for the field.

5 guides

Compressors

Scroll vs. reciprocating, single-phase wiring, grounded/open/shorted failures, protection and burnout cleanup.

5 guides

Condensers & Evaporators

Coil function, airflow effects, approach and split, cleaning, microchannel vs. tube-fin and frozen coils.

12 guides

Controls & Automation

Low-voltage controls, boards, sequencers, relays and automation logic — reading the control circuit instead of guessing.

4 guides

Customer Communication

Explaining a repair to a homeowner, good/better/best options, and building the trust that wins the job and the referral.

5 guides

Diagnostic Method

The systematic troubleshooting mindset — using gauges, clamp meter and thermometer together to run no-cool and no-heat trees that actually find the fault.

5 guides

Ductless Mini-Splits

Inverter operation, line-set and flares, vacuum and nitrogen, fault-code concepts and clean commissioning.

6 guides

Electrical Fundamentals

Ohm's law for techs, series vs. parallel, reading a meter, capacitance, 240V single-phase and the 24V control circuit.

15 guides

Equipment Deep Dives

In-depth walkthroughs of specific HVAC equipment — how it works, how it fails, and how to service it right.

5 guides

Gas Heat & Furnaces

Furnace sequence of operation, ignition, gas valves, flame sensing, heat exchangers, combustion and CO, manifold pressure and venting categories.

5 guides

Geothermal Heat Pumps

Ground-loop heat pumps — loop types, flow, water-to-refrigerant operation, and charging and troubleshooting the geo system.

15 guides

Getting Work — Find HVAC Jobs

How a new HVAC contractor actually lands work: signing up for lead-gen marketplaces (Angi, Thumbtack, Google LSA), home-warranty networks, property managers and GCs — plus how to survive the headaches, read a work order, and get paid.

5 guides

Heat Pumps

Reversing valves, defrost, balance point, aux/emergency heat, charging in heat mode, dual fuel and low-ambient behavior.

14 guides

HVAC Business Operations

Running the business side of HVAC: pricing and flat-rate, callbacks, scheduling, building trust with homeowners, and the operations that turn a tech into a profitable contractor.

5 guides

Hydronics & Boilers

Boilers and hot-water heat — circulators, zones, expansion, air elimination and the controls that run a hydronic system.

5 guides

Indoor Air Quality (IAQ)

Filtration (MERV), humidity control, ventilation, dehumidification and air-cleaning — the facts behind comfort and health.

4 guides

Install Practices

Line-set sizing and insulation, brazing with nitrogen, proper evacuation to 500 microns, and startup and commissioning done right.

5 guides

Load Calc & Design

Manual J load calculation in plain terms — sensible vs. latent, design temps, equipment sizing and why oversizing hurts comfort.

4 guides

Maintenance & PM

Cooling and heating preventive-maintenance tasks — what to actually check, why it matters, and seasonal prep that prevents callbacks.

5 guides

Metering Devices

TXV operation and superheat control, fixed-orifice pistons, bulb charge, hunting and restriction diagnosis.

5 guides

Motors, Capacitors & Contactors

PSC vs. ECM, run and start capacitors, hard-start kits, contactors, relays, motor testing and locked-rotor faults.

5 guides

Refrigerant Charging

Superheat and subcooling methods, weigh-in, fixed-orifice vs. TXV charging, overcharge/undercharge symptoms and charging in cold weather.

6 guides

Refrigerant Guides

Per-refrigerant guides — R-410A, R-22, R-32, R-454B and more: pressures, oils, glide, safety class and handling.

6 guides

Refrigerants

Refrigerant fundamentals — pressure-temperature, glide, oils (POE vs. mineral), recovery, reclaim, A2L safety and EPA 608 rules.

16 guides

Scenario Diagnostics

Real-world service-call scenarios worked end to end — symptom to root cause — so you can pattern-match the next one faster.

7 guides

Starting Your HVAC Business

How a tech goes out on their own: forming an LLC, getting licensed/bonded/insured, startup costs and funding, business banking and bookkeeping, your first hire, and why HVAC businesses fail — and how to survive year one.

5 guides

The Refrigeration Cycle

The compression cycle and its four core processes, what each component does, the P-T relationship, superheat, subcooling and flash gas.

6 guides

Thermostats & Controls

The 24V control circuit, thermostat wiring (R/C/Y/G/W/O/B), transformers, sequencers and low-voltage troubleshooting.

6 guides

Tools & Instruments

Manifold and digital gauges, micron gauge and evacuation, clamp meter, combustion analyzer, recovery machine and nitrogen.

5 guides

Ventilation, ERV & HRV

Mechanical ventilation, energy- and heat-recovery ventilators — how they work, where they help, and how to commission them.

12 guides

Water Heating

Tank and tankless water heaters — sizing, gas and electric, recirculation, venting and the common failures and fixes.

5 guides

Zoning & Controls

Zone dampers, panels and bypass — how zoning works, where it goes wrong, and how to set it up so every room is comfortable.