HVAC know-how for Oklahoma homes & businesses.
HVAC and commercial refrigeration guides for Stillwater and the surrounding Oklahoma communities Sitton Mechanical serves.
Heating, cooling, and commercial refrigeration guidance for Stillwater homes and businesses.
Use these guides to understand common system questions and prepare for a conversation with Sitton Mechanical, LLC. For advice about your equipment, call our team.
Call (405) 780-3034Authorized Daikin Dealer · EPA 608 Certified
Residential HVAC + commercial refrigeration under one roof
Family-owned in Stillwater since the 1990s
Learn the basics
Foundational explainers for homeowners and business owners just figuring out what's wrong or what something means.
Air Conditioning
Why Is My AC Leaking Water Inside the House?
Most indoor AC water leaks trace back to one of three issues: a clogged condensate drain line, a frozen evaporator coil, or a failed drain pan. Here's how to tell which one you have — and the two things you should do in the next five minutes.
Read article Air ConditioningHow to Clean Your AC Condensate Drain Line (and When to Call Us)
A clogged condensate drain is the #1 cause of mid-summer AC water leaks in Stillwater homes. A wet/dry shop vac and three minutes of work usually clears it. Here's the right method — and the three warning signs that mean the clog is the symptom of a bigger problem.
Read article Air ConditioningWhy Is My AC Short-Cycling? 7 Causes a Tech Will Check First
If your AC kicks on for 5–10 minutes, shuts off, and starts again within minutes, your compressor is taking a beating. Short-cycling has 7 common causes, and they range from a $0 filter swap to an oversized system that was never the right fit for the house. Here's how a Sitton tech finds the real one.
Read articleHeat Pumps
How Does a Cold-Climate Heat Pump Work in Oklahoma?
A cold-climate heat pump doesn't make heat — it moves heat. Even at 5°F, there is more usable thermal energy in outdoor air than most homeowners realize. Here's how the physics works in plain English, why 2026 is a different cost picture than 2024, and how Sitton sizes a system for Oklahoma's swing climate.
Read article Heat PumpsWhat Is a Heat Pump Balance Point? (Plain English Explainer)
A heat pump's balance point is the outdoor temperature where the heat it can move into your home equals the heat your home is losing. Above it, the heat pump alone handles heating. Below it, backup heat takes over. Where that line lands changes your monthly bill.
Read articleIndoor Air Quality
MERV Filter Ratings: Which One Is Right for Your Stillwater Home?
MERV runs from 1 to 16 and measures how well a filter traps particles — but the highest number your system can handle is set by your blower, not by your budget. Here's how to choose the right MERV without starving your air handler.
Read article Indoor Air QualityIndoor Air Quality Priorities for Oklahoma Allergy Season
Oklahoma has four allergy seasons a year and one of the highest pollen loads in the country. Filter upgrades alone won't fix it. Here's the real four-lever priority order for indoor air quality in a Stillwater home.
Read articleCommercial Refrigeration
What Is Walk-In Cooler Superheat (and Why It Matters)
Superheat is the single most diagnostic measurement on a walk-in cooler. Get it right and your compressor lives a long, efficient life. Get it wrong by even 5°F and you're shipping liquid refrigerant to a compressor designed only for vapor — a $4,000 mistake. Here's how the math actually works.
Read article Commercial RefrigerationWalk-In Cooler Running Warm: 10 Things a Commercial Tech Checks
A walk-in cooler running warm is on a clock. Here are the 10 things a commercial refrigeration tech checks — in order — to find the fix before your inventory becomes a food-safety event.
Read article Commercial RefrigerationCommercial Refrigeration Preventive Maintenance: The Sitton Checklist
A structured commercial refrigeration PM program turns emergency 3 a.m. calls into scheduled tune-ups during off-hours. Here's the exact quarterly checklist Sitton runs — and why every line item matters for uptime.
Read articleCompare your options
Side-by-side decision guides for the choices Oklahoma homeowners and operators actually have to make.
Air Conditioning
R-32 vs R-454B: The 2026 Refrigerant Transition, Explained
The EPA's AIM Act phased down R-410A production starting in 2025. New residential and light-commercial systems built in 2026 use R-32 or R-454B instead. Here's what changed, what stayed the same, and why homeowners don't need to worry about "mildly flammable" refrigerant.
Read article Air ConditioningSEER2 vs SEER: What Stillwater Homeowners Should Actually Care About
SEER2 replaced SEER as the federal AC efficiency rating on January 1, 2023. The test conditions changed, the numbers dropped by about 10%, and the marketing hype got worse. Here's what actually matters when you compare AC quotes in Stillwater.
Read article Air ConditioningDaikin Fit vs. American Standard Platinum for Stillwater Retrofits
The Daikin Fit and American Standard Platinum sit in the same premium tier of the residential AC and heat-pump market. Sitton is an Authorized Daikin Dealer, but this comparison isn't a pitch — it's the honest side-by-side.
Read articleHeat Pumps
Heat Pump vs. Furnace for Oklahoma Homes — 2026 Guide
Choosing between a heat pump and a furnace used to be straightforward in Oklahoma — gas was cheap, electric was the backup. In 2026, with cold-climate inverter heat pumps hitting 5°F-rated capacity and the federal tax credit expired, the comparison looks different. Here's the honest side-by-side.
Read article Heat PumpsDual-Fuel (Heat Pump + Furnace) vs. All-Electric Heat Pump in Oklahoma
Dual-fuel systems combine a heat pump (cheap heat above the balance point) with a gas furnace (cheap heat below it) and let the thermostat pick the cheaper source hour by hour. That flexibility costs more up front. Here's when it's worth it.
Read articleReady to act
Step-by-step guides for the moments you're ready to schedule a tech, file a rebate, or replace a system.
Maintenance & Tune-Ups
How Often Should I Tune Up My HVAC in Oklahoma?
Twice a year — once in spring before cooling season, once in fall before heating season. That's the short answer. The long answer is more interesting: tune-ups aren't just "checks" — they're the only way to catch capacitor decay, refrigerant slow-leaks, and drain-pan rust BEFORE they become $1,500 emergency calls. Here's exactly what's on a Sitton tune-up and what it costs.
Read article MaintenanceWhat a Manual J Load Calculation Is (and Why Sitton Runs One Every Time)
The right-size HVAC system starts with a Manual J load calculation — not a contractor's rule of thumb. Here's what Manual J actually does, why it matters more than efficiency ratings, and what to demand on every quote.
Read articleLook up an HVAC term
Plain-English definitions for 28 HVAC and commercial-refrigeration terms — SEER2, AFUE, balance point, EPA 608, refrigerant transitions, and more — each one written for Oklahoma homeowners.
Open the glossaryJust call us — we'll talk it through.
Talk to a real Sitton Mechanical technician — never a phone tree. Call to check service and emergency availability in Stillwater and north-central Oklahoma.
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