HVAC stands for Heating, Air Conditioning, and Ventilation. We have covered the heating and air conditioner parts in the respective ‘Heating’ and ‘Air Conditioning’ sections on LearnMetrics.
However, everybody who wants to understand specifications or just learn how to solve some of the basic HVAC problems will find this general HVAC section useful.
There are a million questions that need answering in HVAC. Nobody can possibly address all of them. Here at LearnMetrics, we try to answer the most common ones to help everybody with a better understanding of HVAC.
One of the basics of general HVAC is simple unit conversion. We deal with BTUs, watts, volts, amps, Ah, Wh, °F, °C, CFM, kW, hp, EER, SEER, CEER ratings, and so forth. In most cases, these are either metric or US standard units; in some cases, we use formulas to convert from a specific rating to another specific rating.
To help you out, we have designed some unit converters and calculators. We’ll start with these but you will find some very useful resources such as mold mediation, ductwork, and so forth that pertain to general HVAC and can be useful both in heating, air conditioning, and ventilation systems.
General Unit Converters
- Watts To Amps Converter (With 120V, 220V Examples)
- Convert Amps To Watts (A to W): Simple Calculator (+ Conversion Chart)
- Watts To Volts Converter (W to V): Calculator + Conversion Chart
- Convert kW To Amps: Kilowatt Ampere Calculator + 3 Examples
- Convert kVA To kW With Power Factor (+ Easy Calculator)
- Watts To Kilowatt-Hours: Watts To kWh Calculator + Chart
- Amps To kWh Calculator: Calculate kWh From Amps
- Kilowatt-Hour Calculator: Convert kWh To US Dollars ($)
- 3-Phase Power Calculator + Formula (kW To Amps, Amps To kW)
- kVa To Amps Calculator: How To Convert kVa To Amps? (Examples)
- Convert Watts To BTU: Calculator + Conversion Chart (1 W = 3.412 BTU)
- Convert BTU To Watt: Calculator + Conversion Chart (1 BTU = 0.293 W)
- BTU To kW Air Conditioning Calculator (Quick + Easy Converter)
- kW To BTU Calculator: Convert kW To BTU
- kW To Tons Of Refrigeration Calculator + Chart (kilowatt To Ton)
- Ton To kW: Tons Of Refrigeration To kW Calculator + Chart (TR To kW)
- HP To BTU/hr: Horsepower To BTU For A/C (Calculator + Chart)
- BTU/h To Horsepower Calculator + BTU/h To HP Chart (To 72,000 BTU/h)
- Horsepower To BTU/Min: Convert HP To BTU Per Minute (Calc + Chart)
- Meter Cube Per Hour To CFM Conversion (m3/hr to cfm)
- SCFM Vs CFM Explained: With SCFM To CFM Calculator (+ Chart)
- Amp Hours To Watt Hours Conversion (Ah To Wh): Calculator + Chart
- Amp Hour Calculator: How To Calculate Amp Hours Of A Battery?
- Watt Hours To Amp Hours Conversion (Wh To Ah): Calculator + Chart
- How Many Watts In A 12 Volt Battery? (Calculator + Chart)
- Convert Ah To kWh Calculator
- Convert kWh To Ah (Calculator: Input kWh, Get Ah or mAh)
- BTU to Ton (Easy Convert: 12,000 BTU = 1 Ton)
- BTU To CFM, CFM To BTU: How Many CFM Per BTU In HVAC?
- Convert m3 To kWh (Gas Cubic Meter To kWh Calculator)
- Bar To psi, psig, psia, psid Conversion Calculator (+ Bar To psig Table)
- Convert Pa To PSI: Pascal To PSI Calculator + Conversion Chart
- Convert PSI To Pa: PSI To Pascal Calculator + Conversion Chart
- Convert hPa To PSI: Hectopascal To PSI Calculator + Chart
- Convert kPa To PSI: Kilo Pascals To PSI Calculator + Conversion Chart
- Convert MPa To PSI: Mega Pascal To PSI Calculator + Conversion Chart
- Convert PSI To MPa: PSI To Megapascal Calculator + Chart
- Convert GPa To PSI: Giga Pascals To PSI Calculator + Conversion Chart
- Convert PSIA To PSIG: Calculator + Chart (Incredibly Simple)
- Convert PSIG To PSIA: Calculator + Conversion Chart (Dead Simple)
- Convert Kilowatts To Horsepower (kW to HP Calculator)
- Convert Celsius To Fahrenheit (°C to °F): Calculator, Chart, Equation
- Convert BTU To kWh: Simple BTU To Killowatt-Hour Conversion + Chart
- kWh To BTU Calculator + Chart (Simplest Converter)
- CFH To BTU Calculator For Natural Gas And Propane (Gas Meter)
- Convert MBH To BTU, mBTU To BTU: Boilers, Furnaces, Water Heaters
- MBH To kW Calculator + Chart: Convert mBTU To kW
- MBH To Tons Calculator: Convert mBTU To Tons (+ Chart)
- Therms To MCF Conversion: Calculator + Chart For Natural Gas
- MCF To Therms Conversion Calculator + Chart (Natural Gas)
- MCF To MMBTU Calculator + Chart For Natural Gas
- MMBTU To MCF Conversion: Calculator + Chart (Natural Gas)
- Therms To MMBTU Calculator + Chart (1 Therm = 1/10 MMBTU)
- Natural Gas BCF To MMBTU Calculator + MMBTU To BCF Calculator
- Natural Gas BTU To Cubic Feet Calculator (BTU To CF)
- Natural Gas MMBTU To m3 And m3 To MMBTU Calculator + Chart
- Natural Gas CCF To Therms Calculator + Chart (1 CCF = 1.037 Therms)
- Natural Gas MMSCFD To MMBTU/Day Calculator + Chart
- MMBTU To Therms Calculator + Chart (1 MMBTU = 10 Therms)
- MMBTU Per Day To MMSCFD Calculator For Natural Gas + Chart
- How To Convert Therms To kWh? Calculator + Chart (Natural Gas)
- kWh To Therms Calculator + Conversion Chart (1 kWh = 0.03412956 Therms)
HVAC Ratings Converters
- Convert EER To SEER Rating (Calculator + Chart)
- Convert SEER To EER (Calculator + Chart)
- Convert EER To COP And COP To EER (Calculator)
- EER vs SEER: Difference Between SEER And EER Rating
General HVAC Calculators
- Power Consumption Calculator And Electrical Bill (+ 2 Examples)
- SEER2 Savings Calculator: Which SEER2 Unit Is A Smarter Choice?
- BTU Calculator: How BTU Is Calculated DIY? (With 8.5% Accuracy)
- Is Natural Gas Cheaper Than Electricity For Heating?
- Specific Heat Capacity Calculator + Formula (Equation C = Q /(m ⨉ ΔT))
General HVAC Specifications Explained
- Understanding COP: Coefficient Of Performance Of Heat Pumps
- Understanding SEER2: Minimum SEER Rating In 2023 State-By-State
- SEER Vs SEER2 Rating: What’s The Difference? (+ Implications)
- Understanding EER2 Rating: New 2023 Efficiency Rating For AC Units
- IEER Explained: Integrated Energy Efficiency Ratio (vs EER, SEER)
- ESEER Explained: European Seasonal Energy Efficiency Ratio
- Understanding EAEER: Energy Adjusted Annual Energy Efficiency Ratio
- HSPF Rating: What Is A Good HSPF Rating For Heat Pumps?
- How To Calculate SEER Rating? Here’s How SEER Is Calculated
- Understanding HSPF2 Rating For Heat Pumps (New 2023 Metric)
Refrigerants
- R410A PT Chart: Pressure Temperature Chart For 410A Refrigerant
- R22 PT Chart: Pressure Temperature Chart For -60°F To +155°F
- R134A PT Chart: Pressure Temperature Chart (-49°F To 150°F)
- R404A PT Chart: Pressure Temperature Chart For -49°F To +150°F
- R407c PT Chart: 407c -49°F To 150°F Pressures (+PDF)
- R448a PT Chart: Pressures At -49°F To 150°F Temperatures (+PDF)
- R290 PT Chart: Pressures At -44°F To 120°F Temperatures (+PDF)
- R454B PT Chart: Pressures At -40°F To 150°F Temperatures
- R422D PT Chart: Pressure For -49°F To 150°F Temperatures (+PDF)
- Air Compressor Oil Type: Refrigerant Oil Chart + R22, R134A, R410A Examples
- How Much Freon In 2, 2.5, 3, 3.5, 4, 5, 6 Ton Units? (Pounds)
- What Is GWP In HVAC? Global Warming Potential Explained (R22 Example)
- Refrigerant GWP Chart For 61 Freons (R410A, R134A, R22, etc.)
- List of Low GWP Refrigerants: 69 Refrigerants Below 500 GWP
- All 16 Refrigerant Types + Lists Of Refrigerants (HFC, HC, HO, etc.)
- Target Superheat Chart + Calculator, Formula, R22, 410A Examples
Generators
- What Size Generator Do I Need? (Simple 3-Step Method + Calculator)
- What Size Generator To Run Refrigerator And Freezer? (Crucial: Starting Watts)
- How Much Does It Cost To Run A Generator On Natural Gas? (Calculator)
- 5 Quietest Generators For Home, RV, And Camping (Below 50.7 dB)
- How Long Will A Generator Run On 5 Gallons Of Gas? (Calculator)
- How Many Amps Does A Generator Produce? (500W to 30kW Generators)
- Generator Wire Sizing Calculator + Charts: What Wire Size?
- How Much Propane Do Generators Use Per Hour? (500W – 40kW)
- Generator Cost Per kWh: Diesel, Propane, Natural Gas, Gasoline
- How Long Do Generators Last? (Running Hours, Not Lifespan)
Ductwork
- HVAC Duct Sizing Chart (50-3,050 CFM Duct Charts)
- Duct Velocity Calculator (Air Velocity = Airflow / Duct Cross-Section)
- Rectangular To Round Duct Transformation (Formula + Chart)
- Return Air Grille Sizes: CFM Chart + Grille Size Calculator
- 5 Tell-Tale Symptoms Of Not Enough Return Air From Vents
- How To Increase Airflow To One Room Specifically? (3 Methods)
- Convert FPM To CFM: Air Velocity To Air Flow Calculator + Chart
- Return Duct Size For 2, 2.5, 3, 3.5, 4 And 5 Ton Units
Mold Mediation
- 4 Best HVAC UV Lights For AC/Furnaces (No Mold + Keep Efficiency)
- Mold Inspection And Testing: When Do You Really Need $500+ Inspection?
Wiring
- Wire Gauge Chart For All 44 AWG Wires (+10-200 Amp Wire Sizes)
- Wire Gauge For 20 Amp Circuit: 20A Wire Size + 100 Feet Away
- Wire Gauge For 15 Amp Service + 15 Amp Breaker Wire Size
- 25 Amp Breaker Wire Size + 25A Wire Size 0-500 Feet Away
- 30 Amp Wire Size: What AWG Wire You Need? (220/240V, NEC Code)
- 40 Amp Wire Size: 20A Wire Gauge For 220, 240 Volt Circuit (+ NEC Code)
- 50 Amp Wire Size Details: Gauge, Breaker, 220/240V Example
- Wire Size For 60 Amp Breaker: Which AWG Wire To Use? (NEC CODE)
- 80 Amp Breaker Wire Size + 80A Wire Size 0-500 Feet Away
- 90 Amp Wire Size Calculator + Chart (0-500 Feet Runway)
- 100 Amp Wire Size: Which AWG Wire For 100 Amps? (NEC Code)
- 125 Amp Wire Size Calculator + Chart (0-500 Feet Away)
- 150 Amp Wire Size Explained: Calculator + Chart (0-500 Feet Away)
- Wire Size For 200 Amp Service: What Size For 100, 150 Feet Away? (NEC)
- 400 Amp Wire Size Calculator + Chart (0-500 Feet Runway)
- Thermostat Wiring: How To Wire A Thermostat?
- Thermostat Wire Color Codes For 3-8 Wire Thermostats (Color-By-Color)
- What Is W2 Wire On Thermostat? W2 Wire Thermostat Wiring (2nd Stage)
- 12 AWG Wire Amps, 12 Gauge to mm, mm2, 12 vs 14 vs 10
- How Many Outlets On A 20-Amp Circuit?
- 12V Wire Size Calculator + Chart: What Size Wire You Need?
- Thermostat Not Reaching Set Temperature: 7 Causes + Fixes
- Sizing A Circuit Breaker: Breaker Size Calculator + Amp Chart
- Calculate Wire Size: DC Wire Gauge Calculator (+ 1A-500A Chart)
- AWG To mm2 Chart + Calculator (0-40 AWG To mm2)
- AWG To mm Chart (0-40 AWG Gauge Wires To mm)
- kcmil Wire Size Chart (Ampacity Of 250-2000 MCM Wires)
- How Many Watts Can 6 Gauge Wire Handle? How Many Amps 6 AWG?
- AWG To kcmil, kcmil To AWG Calculator (+ MCM AWG Wire Chart)
- AWG To Circular Mils Chart (For 4/0 AWG To 20 AWG)
- kcmil To mm2 Calculator (Formula + Chart For 250-2000 MCM Wires)
- Wire Gauge Wattage Charts For AWG Wires (4/0 AWG To 14 AWG)
- Aluminum Wire Ampacity Chart (For 4/0 To 12 AWG, 250-2000 kcmil)
- What Is Bigger 4/0 AWG Or 250 MCM Wire? (Specs Comparison)
- 15 Amp Outlet On 20 Amp Circuit: Can You Do That?
- How Many Amps Is A Tesla Supercharger? (Calculator + Chart)
- Ground Wire Size Chart: NEC Grounding Conductor Size Chart
- 6 Gauge Wire Vs 8 Gauge Wire: mm, mm2, Amps Comparison
- Electrical Feeder Size Chart: 100-400 Amps (NEC 310.12)
- How Many Outlets On A 15 Amp, 20 Amp, 30 Amp Circuit? (NEC 210.21)
- How Many Watts Can An Outlet Handle? (110V,120V,220V + 15,20,30A Breakers)
- Extension Cord Wattage Chart: How Many Watts, Amps Cords Handle?
- AWG Wire Resistance Calculator With Ohms Law Formula (+ Examples)
- THHN Vs THWN vs THWN-2 Wires: What Is THWN Wire Anyway?
- What Size Ground Wire For A 200 Amp Service? (3-Step Process)
- Ground Wire Size For 100 Amp Service For Copper, Aluminum Wires
- NEC 310.12 Table: Wire Sizes For 100-400 Amp Services (83% Rule)
- NEC 310.16 Table: Copper And Aluminum Wire Ampacity Chart
- DC Wire Gauge Calculator: What Gauge Wire (12V, 24V, 48V)?
- 12V Voltage Drop Calculator + Chart (0-200 Feet Away)
Insulation
- What Is Insulation R-Value? (+ Insulation R-Value Chart)
- All 9 Types Of Insulation Explained (Materials, R-Values, Applications)
- Insulation R-Value Chart: R-Values Per Inch (For 51 Materials)
- ISO R-Value Chart: Thickness Of Polyiso Insulation (1-20 Inches)
- Rigid Insulation R-Value Per Inch (+ EPS, XPS, ISO Thickness Charts)
- Air Duct Insulation R-Values: ASHRAE Requirements (R-1.9, R-6, R-8, R-12)
- Calculating R-Value: How To Calculate R-Value? (Formula + Units)
- U-Value To R-Value: How To Convert U-Factor To R? (Calculator + Chart)
- Best Attic Insulation R-Value? Recommended R-Values For Attic
- Batt Insulation R-Value Per Inch + R11-R49 Thickness Chart
- Blown-In Insulation R Values: Loose-Fill Chart (Cellulose, Fiberglass, Wool)
- Attic Floor Insulation R-Value: Floor R-Value Chart (R13-R38)
HVAC Tools
Power Consumption Calculations
- How Long Does It Take To Charge A Tesla? (Calculator + Charts)
- How Much Does It Cost To Charge A Tesla? (Easy Calculator)
- How Many kWh Per Day Is Normal? Average Home Daily Electricity Usage (Analysis)
- Average Electricity Bill For 4 Person Household (Survey Analysis)
- How Much Does 1000 Watts Cost Per Hour? (State-By-State Chart)
- How Much Does 500 Watts Cost Per Hour? ($0.05 – $0.22/h)