Showing Posts From
Hvac
- 29 Jun, 2026
Air Conditioning Ton to BTU: Conversion Chart & Calculator
Air conditioning ton to btu conversion — 1 ton = 12,000 BTU/hr. Full ton-to-BTU chart, BTU-to-ton reverse lookup, and when to use tons vs BTU for AC sizing.
- 29 Jun, 2026
Mini Split Air Conditioner Calculator: Size by Room & Zone
Mini split air conditioner calculator — size ductless AC by room square footage, climate, and ceiling height. BTU charts, multi-zone rules, and when mini-split beats central air.
- 29 Jun, 2026
HVAC kWh Calculator: Estimate AC Electricity Usage
HVAC kWh calculator — estimate how many kilowatt-hours your air conditioner uses per hour, day, and month based on tonnage, SEER2, runtime, and local electricity rates.
- 29 Jun, 2026
HVAC Installation Cost Calculator: AC Install & Replacement Prices
HVAC installation cost calculator guide — air conditioning installation cost calculator, central ac installation cost calculator, air conditioning cost calculator, air conditioner replacement cost calculator, furnace and ac replacement cost calculator, and hvac price calculator.
- 29 Jun, 2026
BTU Room Size Air Conditioner: BTU Calculator by Sq Ft
BTU room size air conditioner guide — btu for room size air conditioner, btu size air conditioner, btu calculation formula for air conditioner, btu hvac calculator, and air conditioner capacity calculation.
- 29 Jun, 2026
Central AC Size Calculator: Tons & BTU for Whole-Home Systems
Central ac size calculator guide — central ac calculator, central ac unit calculator, central air conditioner size calculator, central air unit size calculator, and central ac unit size calculator rules.
- 29 Jun, 2026
AC Tonnage per Square Foot: Tons, Sq Ft & Room Size Calculator
AC tonnage per square foot guide — ac ton calculator, ac tonnage calculator per square foot, tons per square foot air conditioning, hvac square footage per ton, square footage calculator for air conditioner, and sizing hvac system calculations.
- 29 Jun, 2026
HVAC Calculators: Free Online Tools for Sizing, Airflow & Cost
Free hvac calculators for sizing, airflow, diagnostics, and cost — btu, tonnage, manual j, cfm, duct size, superheat, seer savings, replacement cost, and more. Plus formula air hvac reference.
- 29 Jun, 2026
Calculating Ductwork Size: CFM, Friction & Duct Calculator Guide
Calculating ductwork size from CFM — sizing ductwork, duct size cfm calculator, hvac duct design calculator, hvac duct sizer, ductwork calculator online, and duct offset calculator basics.
- 29 Jun, 2026
Air Conditioning Load Calculation: Heating & Cooling Load Guide
Air conditioning load calculation explained — heat load calculation hvac, cooling load estimates, hvac system load calculation, manual j heat load calculation, furnace load calculation, and wrightsoft manual j basics.
- 28 Jun, 2026
Free Manual J Calculator Guide
Free manual j calculator guide — manual j calculation online, hvac load calculator free options, ACCA Manual J inputs, and when free tools are enough vs paid software.
- 28 Jun, 2026
HVAC Financing Calculator Guide
HVAC financing calculator guide — hvac loan calculator monthly payment math, 0% dealer financing vs bank loans, and how to compare total cost of financed HVAC replacement.
- 28 Jun, 2026
Commercial HVAC Load Calculation Guide
Commercial hvac load calculation guide — commercial hvac sizing calculator methods, ASHRAE vs ACCA approaches, tons per sq ft rules, and when to use a professional engineer.
- 28 Jun, 2026
Flex Duct Calculator: Size Flexible Duct by CFM
Flex duct calculator guide — flexible duct calculator sizing rules, round duct calculator equivalents, flex vs rigid CFM capacity, and when to upsize flex runs.
- 28 Jun, 2026
CFM Calculation Formula for HVAC
CFM calculation formula in hvac — hvac cfm calculator rules, calculate cfm for room sizing, air duct cfm calculator tables, and airflow formulas every tech should know.
- 28 Jun, 2026
Manual D HVAC: Duct Design Guide
Manual D HVAC guide — ACCA Manual D duct design, wrightsoft manual d workflow, hvac manual d calculation steps, friction rate, and duct sizing vs Manual J.
- 28 Jun, 2026
HVAC Repair Cost Calculator Guide
HVAC repair cost calculator guide — typical hvac repair cost calculator ranges, furnace repair cost calculator prices, duct cleaning cost calculator costs, and when to repair vs replace.
- 28 Jun, 2026
HVAC Replacement Cost Calculator Guide
HVAC replacement cost calculator guide — hvac system replacement cost calculator ranges, new hvac system cost calculator inputs, hvac cost calculator and hvac system cost calculator tips.
- 28 Jun, 2026
SEER Rating Savings Calculator: Is Higher SEER Worth It?
SEER rating savings calculator guide — seer rating calculator formula, seer efficiency calculator comparisons, hvac energy savings calculator payback math, and when to upgrade.
- 28 Jun, 2026
AC Tonnage Calculator: How Many Tons Do You Need?
AC tonnage calculator guide — air conditioning tonnage calculator, air conditioner ton calculator, estimate ac tonnage from sq ft, determining ac tonnage and figuring ac tonnage rules.
- 28 Jun, 2026
Air Conditioning BTU Calculator Guide
Air conditioning BTU calculator guide — hvac btu calculator formula, btu calculator for hvac adjustments, heating and cooling btu calculator tables, and worked examples.
- 28 Jun, 2026
Air Conditioner Size Calculator: Tons & BTU by Sq Ft
Air conditioner size calculator — air conditioner calculator by sq ft, air conditioner unit size calculator rules, air conditioner estimate size tables, and size air conditioning unit calculator tips.
- 28 Jun, 2026
HVAC Duct Calculator: Size Ductwork by CFM
HVAC duct calculator guide — hvac ductwork calculator sizing by CFM, duct calculator cfm tables, air duct calculator rules, and ductwork calculator best practices.
- 28 Jun, 2026
Online Ductulator: Free Duct Sizing Tool Explained
Online ductulator guide — how a duct u lator works, ductulator calculator vs mcquay duct sizer, friction rate and velocity rules, and free duct sizing online.
- 28 Jun, 2026
HVAC Sizing Calculator: How to Size AC, Furnace & Heat Pump
HVAC sizing calculator guide — sizing ac unit calculator rules, air conditioning size calculator by sq ft, heating and cooling calculator size factors, and when to use Manual J.
- 26 Jun, 2026
Commercial HVAC Tons per Square Foot (Sizing Guide)
Commercial HVAC sizing by square feet per ton, with planning figures for offices, retail, restaurants, warehouses, and server rooms — why internal gains dominate and why a block load calc is required.
- 26 Jun, 2026
Duct Size Chart: How to Match Duct Size to CFM
A round duct size chart by CFM, what a ductulator actually does, the friction-rate and velocity rules behind it, how to convert round to rectangular, and how to size supply vs return ducts.
- 26 Jun, 2026
Furnace and AC Replacement Cost (Replacing Both Together)
What it costs to replace a furnace and air conditioner together: combined price ranges by efficiency tier, why a matched system is worth it, the cost breakdown, and when to replace just one.
- 26 Jun, 2026
Heat Load & Cooling Load Calculation: How It Works
How an HVAC load calculation — also called an air conditioning load or AC load calculation — works: the heat-loss formula Q = U × A × ΔT, the sensible and latent parts of a cooling load, a worked residential example, and how to convert load to tonnage.
- 26 Jun, 2026
Will a Higher SEER Save You Money? The Real Math
How much a higher-SEER air conditioner actually saves on your bill, the formula linking SEER to annual cost, a cost-by-rating comparison, and the payback math that decides whether the upgrade is worth it.
- 26 Jun, 2026
HVAC Labor Rate: How to Set Your Hourly Rate
How HVAC contractors set a billable labor rate that actually makes money — the loaded-rate formula, labor burden, overhead, billable-hour reality, flat-rate vs T&M, and a worked example.
- 26 Jun, 2026
How Much Does a New HVAC System Cost in 2026?
Installed cost ranges for central AC, furnaces, heat pumps, and full systems in 2026 by size, efficiency tier, and region. What drives the price up or down, plus tax credits.
- 26 Jun, 2026
Return Air Duct Sizing: How to Size the Return Side
How to size return air ducts: why returns must match supply airflow, a return duct size chart by CFM, single vs multiple returns, filter grille sizing, and the static-pressure problems undersizing causes.
- 26 Jun, 2026
What Size Mini Split Do I Need? (Sizing Chart)
How to size a ductless mini split: a BTU-by-room-size chart, single-zone vs multi-zone sizing, why oversizing wrecks an inverter, and the adjustments that change the number.
- 25 Jun, 2026
Essential HVAC Formulas Every Tech Should Know
The core HVAC formulas in one place: sensible and latent heat, total heat, CFM, tonnage, delta T, static pressure, SEER/EER, and the constants behind them, with worked examples.
- 24 Jun, 2026
How Much Does Furnace Replacement Cost? (2026)
What a new furnace costs to install: price by size, fuel type, and AFUE efficiency, the factors that move the total, repair vs replace, and how to estimate your job.
- 23 Jun, 2026
How Much Does It Cost to Run Central AC?
What central air costs to run per hour, day, and month. The formula tying tonnage, SEER2, and electricity rates to your bill, plus worked examples and ways to cut cooling costs.
- 22 Jun, 2026
EER vs SEER vs SEER2: What Each Rating Means
EER, SEER, and SEER2 all measure AC efficiency differently. What each one means, how they're calculated, how to convert between them, and what counts as a good rating.
- 21 Jun, 2026
How Much Does Central Air Installation Cost? (2026)
What it costs to install or replace central air conditioning: price by tonnage and SEER2, the factors that move the total, install vs replacement, and how to estimate your job.
- 20 Jun, 2026
Dew Point and HVAC: Why It Matters in Duct Design
What dew point is, why ducts sweat and grow mold when surfaces drop below it, the comfort thresholds that feel muggy, and how insulation and vapor barriers prevent condensation.
- 20 Jun, 2026
How to Estimate an HVAC Job: A Contractor's Pricing Guide
A step-by-step way to estimate and price HVAC jobs: counting true job costs, applying the right markup/margin, building an accurate quote, and avoiding the estimating mistakes that kill profit.
- 19 Jun, 2026
What Is Manual J? Heat & Cooling Load Calculation Explained
Manual J is the ACCA standard for calculating a home's heating and cooling load. What it is, the inputs it uses, how heat load and cooling load are calculated, and why it beats rules of thumb.
- 18 Jun, 2026
How Much Does Ductwork Replacement Cost? (2026 Pricing)
What new or replacement ductwork costs — by the foot, by the run, and for a whole house. The factors that move the price, repair vs full replacement, and how to estimate your job.
- 18 Jun, 2026
How to Size a Dehumidifier for Your Home
How to size a dehumidifier by square footage and dampness level, what the 2019 DOE pint rating change means, and when to choose a whole-house unit over a portable.
- 17 Jun, 2026
BTU per Square Foot for Air Conditioning: The Chart and the Math
How many BTU per square foot you need for cooling, with a room-size chart, the climate adjustments that change the number, and why 20 BTU/sq ft is only a starting point.
- 16 Jun, 2026
AC Tonnage by Room Size: Sizing Chart and How to Calculate It
How to size AC tonnage by room or house square footage. A square-footage-to-tonnage chart, the 20 BTU per sq ft rule, climate adjustments, and why room-by-room sizing beats rules of thumb.
- 16 Jun, 2026
Fan Laws Explained: How Blower Speed Affects Airflow
The three fan affinity laws relate blower speed to airflow, static pressure, and power. Why a 10% speed increase costs 33% more power, with worked examples.
- 13 Jun, 2026
What Is CFM and How to Calculate It
CFM is the volume of air your HVAC system moves per minute. What it means, how to convert CFM to tons, the formula to size airflow per room, and how to measure it.
- 11 Jun, 2026
Refrigerant Overcharge vs Undercharge: How to Tell
How to tell if an AC is overcharged or undercharged using superheat and subcooling, the symptoms of each, and why airflow must be verified before touching the charge.
- 10 Jun, 2026
How Many BTU Do I Need? AC Sizing for Every Room and Home
The right BTU for any room or home — the 20 BTU rule, adjustments for climate, ceiling height, sun, and insulation. Includes a quick-reference size table and worked examples.
- 09 Jun, 2026
Manual J vs Rule of Thumb: When to Use Each
Manual J is a room-by-room load calculation; rules of thumb estimate tonnage from square footage. How each works, why oversizing hurts, and when each is appropriate.
- 03 Jun, 2026
What Size Heat Pump Do I Need? A Guide for Cold Climates
Size a heat pump for both cooling and heating with balance-point analysis for cold climates, climate zone factors, and when to add backup heat.
- 27 May, 2026
Furnace Sizing Guide: What Size Furnace for My House?
Find the right furnace BTU for your home by climate zone and insulation with AFUE adjustment, worked examples, and why oversizing is the most common mistake.
- 20 May, 2026
HVAC Delta T: Normal Range and What a Bad Reading Means
What Delta T is in HVAC — the temperature split for AC and furnaces — the normal ranges, how to measure it, and what high or low readings tell you about a system.
- 13 May, 2026
Superheat vs Subcooling: A Field Guide for HVAC Techs
What superheat and subcooling mean, how to measure each, normal target ranges for TXV and fixed-orifice systems, and what readings tell you about refrigerant charge.
- 06 May, 2026
SEER vs SEER2: What Changed and Does It Actually Matter?
SEER2 replaced SEER as the federal efficiency standard in 2023. A side-by-side comparison chart of what changed, how to convert between them, and whether the difference matters when buying.
- 29 Apr, 2026
Is a 95% AFUE Furnace Worth the Extra Cost?
Compare 80% vs 96% AFUE furnaces on fuel cost, payback period, and 15-year total cost. Worked examples for cold and mild climates at different gas prices.
- 22 Apr, 2026
How Much Does a New HVAC System Cost in 2025?
Installed cost ranges for central AC, furnaces, heat pumps, and full systems in 2025 by size, efficiency tier, and region. What drives the price up or down.
- 15 Apr, 2026
Markup vs Margin: How HVAC Contractors Should Price Jobs
The difference between markup and margin, why most HVAC contractors underprice jobs, and how to calculate the right selling price to hit your target profit.
- 08 Apr, 2026
HVAC Static Pressure: How to Test It and What the Numbers Mean
How to measure total external static pressure (TESP), the normal range for residential systems, and how high or low readings point to specific duct and equipment problems.
- 31 Mar, 2026
Mini-Split vs Central Air: Which Is Right for Your Home?
A direct comparison of ductless mini-splits vs central air — upfront cost, operating efficiency, installation, comfort control, and which wins in each scenario.
- 24 Mar, 2026
HVAC Duct Sizing: Manual D vs Rules of Thumb
How to size HVAC ducts using the Manual D friction rate method and simplified rules of thumb, with duct velocity limits and why wrong sizing causes comfort problems.
- 10 Mar, 2026
HRV vs ERV: Which Recovery Ventilator Does Your Home Need?
Heat Recovery Ventilators vs Energy Recovery Ventilators — how they work, what each recovers, which climate conditions suit each, and how to size them.
- 24 Feb, 2026
Heat Pump vs Gas Furnace: Which Is Cheaper to Run?
Side-by-side operating cost comparison of heat pumps and gas furnaces by climate, electricity rate, and gas price. Break-even analysis and when each wins.
- 10 Feb, 2026
ASHRAE 62.2 Ventilation Requirements: What Your Home Actually Needs
The ASHRAE 62.2 whole-building ventilation formula, why tight construction requires mechanical ventilation, and how to size an HRV, ERV, or exhaust fan to meet the standard.