Is Ventora accurate for professional work?

Yes! Our AI is trained on real-world HVAC knowledge and provides code-backed answers with specific references to the IMC, UMC, ACCA Manuals, ASHRAE standards, and EPA Section 608.

What HVAC codes does Ventora reference?

Ventora references the IMC, UMC, IRC, and IFGC mechanical codes, ACCA Manuals J/S/D/T, ASHRAE 15/34/62.1/62.2/90.1, and EPA Section 608 and the AIM Act. We update with each new code cycle.

Can I use Ventora offline?

All 6 calculators work offline. AI and photo features require internet.

How does photo analysis work?

Snap a photo and our AI identifies the equipment — nameplates, furnace control board error codes, wiring diagrams, and gauge sets — checks code compliance, and provides recommendations.

Can I cancel anytime?

Yes, cancel through the App Store anytime during or after your 7-day free trial.

Ventora is an AI-powered HVAC calculator and reference app designed for HVAC technicians, installers, and apprentices. It includes professional tools like superheat & subcooling, refrigerant charge, duct sizing, airflow/CFM & static pressure, BTU/load, and hydronic calculators, plus a comprehensive HVAC code reference and photo analysis.

What HVAC calculators does Ventora include?

Ventora includes six professional HVAC calculators: Superheat & Subcooling, Refrigerant Charge, Duct Sizing, Airflow / CFM & Static Pressure, BTU / Load, and Hydronic (water-side). Each is built for real field work with results interpreted for you.

Does Ventora have an AI assistant for HVAC questions?

Yes, Ventora features an advanced AI assistant trained on real-world HVAC knowledge. Ask about refrigerants, error codes, sequences of operation, wiring, and codes, and get instant, accurate answers backed by mechanical code and standards references.

Is Ventora free to use?

Ventora is free to try with a 7-day free trial, then $19.99/month. Cancel anytime through the App Store. The subscription unlocks the AI assistant, all six calculators, HVAC code reference, photo analysis, and guided troubleshooting.

How do I calculate superheat?

Superheat = Suction Line Temperature − Evaporator Saturation Temperature, in °F. On a TXV system, target 8–14°F. Low superheat (under about 5°F) risks liquid floodback and overcharge; high superheat (over about 20°F) usually means a starved or undercharged system. Ventora's Superheat & Subcooling Calculator looks up saturation temperatures from the PT chart for R-410A, R-454B, R-22, R-32, and R-407C.

How do I calculate subcooling?

Subcooling = Condenser Saturation Temperature − Liquid Line Temperature, in °F. Target roughly 10–18°F on most systems. Low subcooling points to an undercharge; high subcooling points to an overcharge or a liquid-line restriction. Ventora computes it automatically once you enter your liquid line pressure and temperature.

What is the target superheat for a fixed-orifice system?

For fixed-orifice (piston) metering, use the Carrier method: Target Superheat = 3 × (indoor Wet Bulb) + (80 − Outdoor Dry Bulb) − 1, in °F. Ventora's Refrigerant Charge Calculator computes target superheat from indoor wet-bulb and outdoor dry-bulb temperatures and compares it to your measured superheat.

How do I size ductwork?

Duct sizing starts with the friction rate: Friction Rate = (Available Static Pressure ÷ Total Equivalent Length) × 100, in inches of water column per 100 ft. Aim for roughly 700–900 FPM on supply and 600–700 FPM on return. Ventora's Duct Sizing Calculator recommends round diameters and equivalent rectangular sizes following ACCA Manual D principles.

How do I calculate CFM and airflow?

The core airflow formula is CFM = BTU ÷ (1.08 × ΔT). You can also derive CFM from velocity (CFM = FPM × Area in ft²) or velocity from velocity pressure (V = 4005 × √VP). A common target is about 400 CFM per ton. Ventora's Airflow / CFM Calculator handles all three methods plus total external static pressure.

What is a good total external static pressure?

Total External Static Pressure (TESP) should generally stay at or below 0.50 iwc on typical residential equipment. Readings above 0.80 iwc indicate a serious airflow restriction — often a dirty filter or coil, closed registers, or undersized ductwork. Ventora flags high static pressure automatically.

How do I calculate a cooling load?

Sensible load = 1.08 × CFM × ΔT; Total load = 4.5 × CFM × Δh; Latent load = 0.68 × CFM × ΔW; Tons = BTU ÷ 12,000. For quick estimates Ventora offers BTU/sq-ft rules of thumb by climate zone — but a full ACCA Manual J is required for real equipment sizing, since oversizing is the number-one install error.

What refrigerants does Ventora support?

Ventora includes PT data and charging guidance for R-410A, R-454B, R-22, R-32, and R-407C. It also covers the AIM Act phase-down: as of January 1, 2025, new residential and light-commercial systems must use lower-GWP refrigerants such as R-454B (GWP 466) in place of R-410A (GWP 2,088).

Do I need EPA 608 certification to handle refrigerant?

Yes. Under EPA Section 608 of the Clean Air Act, anyone who purchases or handles refrigerant must be certified — Type I (small appliances), Type II (high-pressure), Type III (low-pressure), or Universal. Ventora's code reference covers 608 requirements including mandatory leak repair, recovery, and recordkeeping rules.

How do I troubleshoot a system that isn't cooling?

The most common causes are a dirty air filter or restricted airflow, a low refrigerant charge or leak, a frozen evaporator coil, a dirty condenser coil, or a failed run capacitor. Ventora's guided troubleshooting walks you through no-cooling, no-heat, airflow, electrical, and refrigerant faults step by step.

Does Ventora work for commercial HVAC technicians?

Yes, Ventora is designed for both residential service techs and commercial installers. It includes commercial-focused tools like hydronic (water-side) heat-transfer calculations, airflow and static pressure analysis, and a code reference covering the IMC, ASHRAE 62.1/90.1, and Manual N commercial loads.

What is the best app for HVAC technicians?

Ventora is built specifically for HVAC technicians. It combines an AI assistant, six professional calculators (superheat & subcooling, refrigerant charge, duct sizing, airflow/CFM, BTU/load, hydronic), HVAC code reference, photo analysis, and guided troubleshooting in one mobile app. Free to try with a 7-day trial, then $19.99/month.

Superheat & Subcooling Calculator

Diagnose refrigerant charge in seconds. Calculate superheat and subcooling for R-410A, R-454B, R-22, R-32, and R-407C systems with PT chart saturation lookup and instant charge interpretation.

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What is Superheat & Subcooling?

Superheat is the number of degrees the refrigerant vapor is heated above its saturation (boiling) temperature at a given pressure. Subcooling is the number of degrees the liquid refrigerant is cooled below its saturation (condensing) temperature. Together they are the two most important measurements for diagnosing refrigerant charge and system performance.

Superheat protects the compressor by confirming that only vapor — never liquid — returns to it, while subcooling confirms the condenser is fully condensing refrigerant into liquid before it reaches the metering device. On a properly charged TXV system, technicians target 8-14°F of superheat and 10-18°F of subcooling.

Superheat & Subcooling Formulas

Superheat Formula

Superheat = Suction Line Temp − Evaporator Saturation Temp

Measure suction line temperature near the outdoor unit and look up the evaporator saturation temperature on a PT chart using the measured suction (low-side) pressure. Target range on TXV systems: 8-14°F.

Subcooling Formula

Subcooling = Condenser Saturation Temp − Liquid Line Temp

Look up the condenser saturation temperature on a PT chart using the measured liquid/high-side pressure, then subtract the liquid line temperature measured at the condenser. Target range: 10-18°F (verify against the equipment charging label).

Charge Diagnosis: Target Ranges & Interpretation

Superheat and subcooling only mean something when you compare them to their target ranges. Read the two numbers together to pinpoint what a system is actually doing:

Target superheat (TXV systems): 8-14°F. Fixed-orifice systems use the manufacturer's charging chart instead.
Target subcooling: 10-18°F — confirm the exact value on the equipment's charging label.
High superheat + low subcooling: undercharged or a refrigerant leak — find and repair the leak before adding refrigerant.
Low superheat + high subcooling: overcharged — recover refrigerant.
High superheat + high subcooling: a restriction in the liquid line or metering device (starved evaporator with refrigerant backing up in the condenser).
Low superheat (below 5°F): flooding risk — liquid refrigerant is returning to the compressor and can cause valve or bearing damage.

Always confirm charge against the manufacturer's charging chart and current operating conditions — outdoor dry bulb, indoor wet bulb, and airflow all shift the target numbers.

PT Chart Reference (Saturation Temperatures)

Saturation Temp	R-410A (psig)	R-22 (psig)	R-454B (psig)
32°F	101	58	99
40°F	118	69	116
45°F	130	76	128
95°F	290	182	285
110°F	365	226	358
120°F	418	260	410

Approximate saturation pressures for quick field reference. The 32-45°F rows are typical evaporator (low-side) conditions; the 95-120°F rows are typical condenser (high-side) conditions. R-454B and R-407C are zeotropic blends with temperature glide — use dew point for superheat and bubble point for subcooling. These values are estimates; always confirm against the manufacturer's PT chart or a digital PT tool before charging.

Superheat & Subcooling Calculation Example

Problem:

An R-410A split system with a TXV reads 105 psig suction pressure with a 60°F suction line temperature, and 330 psig liquid pressure with a 96°F liquid line temperature. Find the superheat and subcooling and diagnose the charge.

Solution:

Evaporator saturation temp at 105 psig ≈ 34°F

Superheat = 60°F − 34°F

Superheat = 26°F (above the 20°F starved threshold)

Condenser saturation temp at 330 psig ≈ 101°F

Subcooling = 101°F − 96°F

Subcooling = 5°F (at the low-charge threshold)

High superheat combined with low subcooling points to an undercharged system or refrigerant leak. Find and repair the leak before adding refrigerant, then verify against the manufacturer's charging chart for the current operating conditions.

Skip the Math - Use Ventora

Get instant superheat and subcooling calculations on your phone. Pick your refrigerant, enter your pressures and line temperatures, and get results in seconds — with saturation lookup and a plain-language charge diagnosis.

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