📐 Size Selection
The first step in any CTAPRO project is defining the unit size. Open the Select Size dialog to specify airflow, velocity, and altitude.
Select Size dialog — specify airflow and model
Primary Parameters
| Parameter | Input Type | Units | Range |
|---|---|---|---|
| Supply Air Flow | Numerical | CFM (selectable) | 0–999,999 |
| Coil Air Velocity | Numerical | m/s | 0–10.0 |
| Exhaust Air Flow | Numerical | CFM (selectable) | 0–999,999 |
| Altitude ASL | Numerical | m | 0–9,999 |
| Air Density | Calculated | kg/m³ | Variable |
Flow Unit Options
| Unit | Full Name | Notes |
|---|---|---|
| CFM | ft³/min | Most common |
| m³/h | Cubic meters/hr | Metric standard |
| m³/s | Cubic meters/sec | SI base |
| l/s | Liters/sec | Common metric |
| l/h | Liters/hr | Water systems |
| ft³/s | Cubic feet/sec | US engineering |
| GPM | Gallons/min | Water/pumps |
💡 Tip
Target face velocity: 2.5–3.0 m/s for optimal performance. Green row in model table = CTAPRO recommendation.
🔍 Model Selection
After entering airflow, CTAPRO shows available models with calculated face velocity for each.
Model Selection — populated with 15,000 CFM example
Example: 15,000 CFM
| Model | Coil Velocity | Height | Width | Verdict |
|---|---|---|---|---|
| PTA-63T-9 | 3.92 m/s | 1400 mm | 1930 mm | Too fast |
| PTA-63T-10 | 3.02 m/s | 1720 mm | 1930 mm | Good |
| PTA-63T-11 | 2.49 m/s | 2020 mm | 1930 mm | Ideal ✓ |
| PTA-63T-12 | 2.08 m/s | 2020 mm | 2230 mm | OK (large) |
| PTA-63T-13 | 1.80 m/s | 2020 mm | 2530 mm | Oversized |
Unit Series
| Series | Profile Thickness | Panel Thickness | Use |
|---|---|---|---|
| PTA63 | 60 mm | 63 mm | Standard — most projects |
| PTA50 | 50 mm | 50 mm | Mid-range |
| PTA25 | 25 mm | 25 mm | Economy / light duty |
🏗️ Construction Options
Materials
| Element | Standard Option |
|---|---|
| Internal Sheet | Galvanized Steel 0.8 mm |
| External Panel | Galvanized Polyurethane Painted 1.2 mm |
| Internal Sheet Metal | Galvanized Steel / Stainless Steel AISI 304 |
Insulation (7 types)
| Type | Density | Thickness |
|---|---|---|
| G.Wool 40 Kg/m³ | 40 kg/m³ | 44 mm |
| G.Wool 29kg/m² with BTG | 29 kg/m² | Variable |
| G.Wool 32kg/m² with BTG | 32 kg/m² | Variable |
| G.Wool 32kg/m² with SEP | 32 kg/m² | Variable |
| G.Wool 25kg/m² | 25 kg/m² | Variable |
| G.Wool 40/m³, 44mm +BTG | 40 kg/m³ | 44 mm |
| G.Wool 40/m³, 44mm +SEP | 40 kg/m³ | 44 mm |
Baseframe (11 options)
| Type | Material | Height |
|---|---|---|
| Galvanised 80 mm | Galvanized steel | 80 mm |
| Galvanised 100 mm | Galvanized steel | 100 mm |
| Galvanised 120 mm | Galvanized steel | 120 mm |
| Polyurethane Painted 80 mm | Painted Steel | 80 mm |
| Polyurethane Painted 100 mm | Painted Steel | 100 mm |
| Polyurethane Painted 120 mm | Painted Steel | 120 mm |
| Profile UNP 80 | UNP profile | 80 mm |
| Profile UNP 100 | UNP profile | 100 mm |
| Profile UNP 120 | UNP profile | 120 mm |
| Without Baseframe | N/A | N/A |
Drain Pan Materials
| Material | Thicknesses Available |
|---|---|
| Stainless Steel AISI 304 | 1.25 mm, 1.5 mm, 2.0 mm |
| Stainless Steel AISI 316 | 1.25 mm, 1.5 mm, 2.0 mm |
Roof Options
| Option | Description |
|---|---|
| Without Roof | Indoor installation |
| Flat Roof Painted | Standard outdoor |
| Flat Roof with Elevation | Raised for drainage |
| Sloped Roof Painted | Maximum water runoff |
🌡️ Psychrometry
The Psychrometry tab defines environmental conditions for summer and winter design calculations.
Psychrometry dialog — summer/winter conditions
Psychrometry calculation parameters
Summer Inlet Conditions
| Air Type | Temperature | RH | Airflow |
|---|---|---|---|
| Fresh Air | 32°C | 50% | 15,000 CFM |
| Recirculated Air | 26°C | 50% | 0 CFM |
Winter Inlet Conditions
| Air Type | Temperature | RH | Airflow |
|---|---|---|---|
| Fresh Air | 5°C | 80% | 15,000 CFM |
| Recirculated Air | 20°C | 50% | 0 CFM |
Israel Reference Conditions
| Season | Temp Range | RH Range | Supply Target |
|---|---|---|---|
| Summer | 32–38°C | 40–50% | 12–14°C / 90–95% RH |
| Winter | 3–10°C | 70–90% | 24–26°C / 50–60% RH |
Israel Altitude Reference
| City | Altitude | City | Altitude |
|---|---|---|---|
| Tel Aviv | 5 m | Haifa | 25 m |
| Beer Sheva | 260 m | Jerusalem | 750 m |
| Eilat | 12 m | Safed | 900 m |
💡 Tip
Jerusalem (750m): air density 1.10 kg/m³ vs Tel Aviv (5m): 1.20 kg/m³ — this significantly affects fan sizing and coil performance.