Air Conditioning Calculator
Answer a few quick questions and we’ll size the right air conditioning system for your room — instant BTU, kW and recommended evaporator size.
Project details
Ventilation Calculator
Size room airflow and duct diameter per UK Part F guidance — instant L/s, m³/h, CFM and duct size.
Room & airflow
Design Airflow — Office
80.0 L/s
m³/h
288.0
CFM
169.5
Duct diameter
184 mm
Volume
48.0 m³
Breakdown
- Room volume
- 48.0 m³
- Airflow (ACH method)
- 80.0 L/s (288.0 m³/h)
- Airflow (per person, 10 L/s)
- 40.0 L/s
- Duct area required
- 0.0267 m²
- Design airflow
- 80.0 L/s
UK Part F — typical minimum extract rates
- Kitchen
- 13 L/s
- Utility
- 8 L/s
- Bathroom
- 8 L/s
- WC
- 6 L/s
Refrigerant Slider
Convert between saturation pressure and temperature for common HFC refrigerants. For field guidance only — use manufacturer P–T charts for commissioning.
R410A — saturation
8.35 bar(g)
Dew °C
5.00
Bubble °C
4.97
Glide K
0.03
Phase
dew
Properties — R410A
- Class
- HFC blend
- Safety group
- A1
- GWP (AR4)
- 2,088
- ODP
- 0
- Oil
- POE
- Nominal glide
- 0.1 K
- Boiling pt (1 atm)
- -51.6 °C
- Critical temp
- 71.36 °C
Saturation values are calculated from fitted curves and intended for guidance only. Use manufacturer P–T charts for commissioning and safety-critical work.
F-Gas & EN378 Safety Calculator
Check refrigerant concentration against EN378-1 practical and flammability limits, and get the matching UK F-Gas leak-check interval.
EN378 Design Check
Requires further investigation
Concentration vs EN378 limits
- Calculated concentration
- 0.0600 kg/m³
- EN378 practical limit (RCL)
- 0.0610 kg/m³
- % of practical limit
- 98.4%
- LFL (flammability)
- 0.307 kg/m³
- % of LFL
- 19.5%
- ATEL (toxicity)
- 0.3 kg/m³
UK F-Gas (Regulation 517/2014)
- GWP (AR4, 100-yr)
- 675
- Charge
- 3 kg
- CO₂-equivalent
- 2.02 t CO₂e
- Mandatory leak check
- Not required (< 5 tCO₂e)
Indicative only. Verdict uses EN378-1 simplified rules: occupied spaces compared to the practical limit (50% triggers review), authorised-access areas compared to 0.5×LFL for flammable gases. Plant rooms and outdoor systems are subject to ventilation/detection requirements rather than concentration limits. For certification, undertake the full EN378 assessment.
F-Gas GWP & tCO₂e Calculator
Refrigerant → charge (kg) → GWP → tonnes CO₂e → the legal F-Gas leak-check frequency, with your next check date.
System 1
GWP (AR4)
2,088
Charge
5 kg
CO₂ equivalent
10.44 t
Legal leak-check frequency
Every 12 months
Band: 5 to under 50 tCO2e
- • Records must be kept for 5 years (charge, checks, recovery, engineer details).
- • AR5 GWP (reporting reference only): 1,924 — legal thresholds use AR4.
Based on the GB F-Gas Regulation (retained EU 517/2014) Articles 4 & 5 using AR4 GWP values. Hermetically sealed systems below 10 tCO₂e and labelled as such are exempt from leak checking. Indicative guidance only — confirm against current legislation.