ASTRACOAT — Unified Performance Tool | EN 410 / ISO 9050 + EN 673 (v1.30 Unified)

General inputs

Batch import (N samples)

Glass-1 thickness (mm) — single or comma list (N)

How many samples (N) to calculate?

SGU product name(s) — single or comma list (N)

SGU ε film-side (Rf) — single or comma list (N)

SGU ε glass-side (Rg) — single or comma list (N)

Outer coating position (IGU outer lite)

Outside heat transfer coefficient he (W/m²·K)

Typical EN 673 external: 23 W/m²·K (wind ~4 m/s).

Inside heat transfer coefficient hi mode

If manual, this hi is used for both SGU and IGU calculations.

Spectra input format

For combined .txt, wavelength can be in microns (e.g., 0.32) and will be converted to nm automatically.

Emissivity source

If “combined” file includes Emis= a b, the tool auto-fills εRf=a (front/film-side) and εRg=b (back/glass-side) per file. Manual inputs still work as fallback.

Batch Transmission files (Tr) — select N files Batch Glass-side Reflectance files (Rg) — select N files Batch Film-side Reflectance files (Rf) — select N files

Pairing tries two methods:

1) Smart filename match (removes “tr/rg/rf/sample” tokens anywhere)

2) If still no match: pairs by order (Tr[i], Rg[i], Rf[i])

Laminated SGU builder (optional)

Glass-1 + PVB/film(s) + Glass-2

Enable laminated sample If enabled, the tool combines Glass-1 + interlayer stack + Glass-2 before IGU.

Glass-2 spectra input format

Glass-2 thickness (mm) — optional label

Glass-2 Batch Tr files (select N or 1 common file) Glass-2 Batch Rg files Glass-2 Batch Rf files Flip Glass-2 (swap Rg↔Rf)

Interlayers mode

Interlayer file can be combined (.usr or columns λ Tr Rg Rf) OR Tr-only (λ Tr). If only Tr is provided, Rg=Rf=0 and emissivity defaults to 0 unless header provides Emis.

IGU partner

Common OR Batch

IGU partner mode

Inner coating position (partner lite)

IGU build order

Use this if your IGU is assembled in reverse order compared to default.

Quick schematic

DGU product name(s — single or comma list (N)

Gap thickness (mm) — single or comma list (N)

Gas input mode

Gas value(s)

How to use: choose one gas in dropdown (applies to all N). Or select “Comma list (N values)” and type like: Argon,Argon,Air. Allowed: Air, Argon, Krypton, Xenon, SF6

Partner product name(s) — single or comma list (N)

Outside temperature Te (°C) — single or comma list (N)

Inside temperature Ti (°C) — single or comma list (N)

Partner thickness (mm) — single or comma list (N)

Partner ε glass-side (Rg) — single or comma list (N)

Partner ε film-side (Rf) — single or comma list (N)

Common partner files (1 set)

Partner spectra format

Partner Tr

Partner Rg

Partner Rf

Gap-side reflectance check: RgapOuter = S2, RgapInner = S3 (UV/Solar/Vis).

Audit / Messages

Debug

Select batch files → Compute SGU + IGU.

#	Outer sample	Partner sample	Match mode
Choose partner files to preview pairing.

Summary table (auto appends every compute)

Sortable + Searchable

Optical summary values and SHGC are shown/exported in percentage.

SGU / Laminate SGU

#	SampleKey	System	Product	Combination	Thickness	Gas	Sol T (%)	Sol Rg (%)	Sol Rf (%)	Vis T (%)	Vis Rg (%)	Vis Rf (%)	UV T (%)	UV Rg (%)	UV Rf (%)	IR T (%)	IR Rg (%)	IR Rf (%)	SHGC (%)	SC	Sel	U	εS1	εS2	εS3	εS4

IGU / DGU

#	SampleKey	System	Product	Combination	Thickness	Gas	Sol T (%)	Sol Rg (%)	Sol Rf (%)	Vis T (%)	Vis Rg (%)	Vis Rf (%)	UV T (%)	UV Rg (%)	UV Rf (%)	IR T (%)	IR Rg (%)	IR Rf (%)	SHGC (%)	SC	Sel	U	εS1	εS2	εS3	εS4

Click any header to sort. Use search to filter. Summary export writes separate SGU and IGU sheets in one Excel file.

Diagram (based on current selections)

S1–S4

Research equations used in this tool

EN 410 + EN 673 + IR

This tab documents the core equations implemented in ASTRACOAT – Performance Tool. Symbols follow common glazing notation. (Rg = glass-side reflectance, Rf = film-side reflectance.)

Weights tables used (audit view)

This viewer shows the exact wavelength grid and weights used for band-averaging in this tool.

—

λ (nm)	weight

A) EN 410 band-weighted optical properties

For any spectrum X(λ) sampled/interpolated at the standard tabulated wavelengths:

X̄_band = Σ[ X(λᵢ) · w(λᵢ) ] / Σ[ w(λᵢ) ]

Where weights are per the EN 410 tables used in this tool: Solar uses S(λ)Δλ, Visible uses D(λ)V(λ)Δλ, UV uses S(λ)Δλ (UV subset), and IR uses the infrared subset of the solar weighting table. Input spectra are converted to absolute mode before clamping to physical 0–1 limits.

B) IGU (double glazing) spectral combination (multiple reflections)

Two lites separated by a non-absorbing gap (optical coupling only): Outer lite has (T₁, R_out₁, R_gap₁). Inner lite has (T₂, R_gap₂, R_room₂).

Den(λ) = 1 − R_gap₁(λ) · R_gap₂(λ) T_IGU(λ) = T₁(λ) · T₂(λ) / Den(λ) R_out_IGU(λ) = R_out₁(λ) + [ T₁(λ)² · R_gap₂(λ) ] / Den(λ) R_room_IGU(λ) = R_room₂(λ) + [ T₂(λ)² · R_gap₁(λ) ] / Den(λ)

The tool reports IGU Rg = outside reflectance (R_out_IGU) and IGU Rf = room-side reflectance (R_room_IGU). “Gap-side reflectance” checks shown in results are the band-averages of R_gap₁ and R_gap₂.

C) Surface convention and mapping (your fixed rule)

Rg = reflectance measured from GLASS side (uncoated side / substrate side) Rf = reflectance measured from FILM side (coating side)

For IGU mapping, the tool uses your “coating position” selections: Outer lite: S1 (outside) / S2 (gap). Inner lite: S3 (gap) / S4 (room). Depending on S1/S2 and S3/S4 choices, (Rg,Rf) are assigned to outside/gap or gap/room accordingly.

D) EN 673 heat transfer and U-value (as implemented)

External and internal surface coefficients:

h_e = 23 W·m⁻²·K⁻¹ h_i = 3.6 + 4.4·(ε_i / 0.837) W·m⁻²·K⁻¹

Gap heat transfer (gas conduction + radiation):

T_m = (T_e + T_i)/2 (°C), T_mK = T_m + 273.15 (K) Pr = μ·c_p / λ Gr = g·s³·ΔT·ρ² / (T_mK·μ²) Nu = 1 for Gr·Pr < 1×10⁴ Nu = 0.42·(Gr·Pr)^(1/4) for 1×10⁴ ≤ Gr·Pr < 1×10⁷ Nu = 0.049·(Gr·Pr)^(1/3) for Gr·Pr ≥ 1×10⁷ h_g = Nu·λ / s h_r = 4·σ·T_mK³ / ( 1/ε_1 + 1/ε_2 − 1 ) h_s = h_g + h_r

Overall U-value:

R_glass = d₁/k_glass + d₂/k_glass (m²·K·W⁻¹) h_t = 1 / ( 1/h_s + R_glass ) U = 1 / ( 1/h_e + 1/h_t + 1/h_i )

Gas properties (ρ, μ, λ, c_p) are taken from the table inside the tool and interpolated vs temperature.

E) SHGC (g), SC, selectivity (as used in the tool)

The tool uses a lite-split SHGC approximation for IGU work. Solar absorption is first split into outer-lite and inner-lite contributions, then each contribution is multiplied by an inward-flowing fraction obtained from the thermal resistance network. This is closer to WINDOW-style behavior than the old single lumped absorption approach.

For each wavelength λ: A_outer(λ) = A1,out(λ) + T1(λ)·R2,gap(λ)·A1,gap(λ) / [1 − R1,gap(λ)·R2,gap(λ)] A_inner(λ) = T1(λ)·A2,gap(λ) / [1 − R1,gap(λ)·R2,gap(λ)] where A1,out = 1 − T1 − R1,out A1,gap = 1 − T1 − R1,gap A2,gap = 1 − T2 − R2,gap q_i = F_outer·A_outer,sol + F_inner·A_inner,sol g (SHGC) = τ_sol + q_i SC = g / 0.87 Selectivity = T_vis / g

Note: this is still an engineering approximation, but it is much stronger than the old q_i = α·h_i/(h_e+h_i) method for coated IGUs.

F) Spectral energy balance

At each wavelength, transmission, reflection, and absorption must conserve energy:

T(λ) + R(λ) + A(λ) = 1

G) Directional laminate optical propagation

For two directional layers combined recursively, preserving front/back asymmetry of coated glass:

T₁₂(λ) = T₁(λ)·T₂(λ) / [ 1 − Rb₁(λ)·Rf₂(λ) ] Rf₁₂(λ) = Rf₁(λ) + [ T₁(λ)² · Rf₂(λ) ] / [ 1 − Rb₁(λ)·Rf₂(λ) ] Rb₁₂(λ) = Rb₂(λ) + [ T₂(λ)² · Rb₁(λ) ] / [ 1 − Rb₁(λ)·Rf₂(λ) ]

Here, Rf is front / film-side reflectance and Rb is back / glass-side reflectance. This is the engineering directional-recursion concept used for laminate propagation when full n,k transfer-matrix optics are not available.

H) Coated glass asymmetry

Rf ≠ Rg

Coated glass is generally asymmetric. Therefore coating orientation and user flip choices must be preserved in SGU, laminate, and IGU calculations.

I) Surface numbering convention for laminate / IGU

Standard outside-to-inside surface numbering is used for diagram and emissivity mapping:

S1 = outermost exposed surface S2 = inner side of first lite S3 = cavity-facing / laminate-facing side of second lite S4 = innermost exposed surface

This convention is essential for correct coating placement, emissivity assignment, and front/back reflectance handling.

J) Effective emissivity between two radiating surfaces

ε_eff = 1 / ( 1/ε₁ + 1/ε₂ − 1 )

This effective emissivity is used in long-wave radiative exchange across cavities.

K) Practical notes for researcher teams

Directional reflectance of coated glass must always preserve the distinction between glass-side and film-side measurements.
Laminate optical results are sensitive to coating orientation and interlayer placement.
IGU optical results depend on cavity-side reflectance mapping and multiple reflections between gap-facing surfaces.
Thermal calculations use exposed-surface emissivities, while summary reporting may include internal laminate interface emissivities for engineering interpretation.
For exact Optics / WINDOW parity on coated laminate reflection, a full transfer-matrix engine based on layer n,k,d is the next upgrade path.

ASTRACOAT — Unified Performance Tool | EN 410 + EN 673 (v1.30 Unified)