AirSelect3D Blog
AHU engineering, selection
and compliance — explained.
Practical articles on air handling unit selection, Eurovent ECP-05-2026 certification, ErP compliance, specific fan power, heat recovery and acoustics — written by the team building AirSelect3D.
Web-Based vs Desktop AHU Selection Software: The End of ClickOnce
Why installer-based AHU selection tools are being replaced by browser-native ones — what ClickOnce actually was, what breaks it, and where the vendor DLLs live now.
Certified Manufacturer Data vs Curve Fits in AHU Selection Software
How to tell whether an AHU selection tool calls real supplier selection engines or interpolates catalogue curves — and where the two diverge enough to change an energy class.
How to Read an AHU Technical Data Sheet: A Consulting Engineer's Guide
A reading order and five pieces of arithmetic that let you verify an AHU technical data sheet yourself — SFP, coil duty, heat recovery efficiency, pressure budget and acoustics.
Humidification in AHUs: Steam vs Adiabatic and VDI 6022 Hygiene Rules
Steam and adiabatic humidification solve different problems in an AHU — energy use, saturation distance and hygiene risk under VDI 6022 all drive the choice. Here's how to spec it correctly.
Night Purge, Free Cooling and Mixed-Air: AHU Control Modes to Spec
Night purge, free cooling and mixed-air economizer modes each demand different damper authority, leakage class and fan turndown — what your AHU spec must state to make them work.
The Real Cost of Oversizing an AHU: Capex, Footprint, Part-Load SFP
Going one casing size up cuts SFP, but oversizing past that point adds capex and footprint faster than it saves — and hurts twice at part load. Worked numbers.
Plate HRS Frost Protection: Preheat vs Bypass vs Modulation
Frost protection for plate heat recovery compared — preheat coil, full bypass and modulating control, with the seasonal energy cost of each strategy priced out.
From SFP Class to Euros — Annual Fan Energy Cost and Payback
Convert SFP_int into annual kWh and euros: the Δp/η identity, a 5 000 m³/h worked example, and how to justify one casing size up to the building owner.
AHU Airflow Arrangements — Stacked, Side-by-Side and Cross-Flow Bridges
How supply/extract routing decides AHU footprint, height and duct connection sides — stacked vs side-by-side layouts, cross-flow bridges and deck-scoped keys.
AHU Airflow Sizing: From Heat Load (kW) to Supply-Return ΔT
How the sensible heat equation converts a calculated heating or cooling load into the airflow an AHU must deliver, and how supply-return ΔT is chosen.
What BIM Coordinators Actually Need From an AHU Export (DXF vs IFC, LOD, Clash)
A BIM coordinator's view of AHU exports — when DXF is enough, when you need IFC, what LOD 300 vs 350 requires, and how connection points survive a clash check.
Cooling Coil Selection: Rows, Circuiting, ADP and Carry-Over Limits
How row count, circuiting, apparatus dew point, bypass factor and carry-over velocity interact in AHU cooling coil selection, with a worked sizing example.
EC Plug Fans vs Belt-Driven: Efficiency, Redundancy, ErP Implications
EC plug fan walls vs belt-driven centrifugal fans in AHUs - efficiency at part load, N+1 redundancy, maintenance, and the 2026/2027 ErP fan ecodesign angle.
Psychrometrics for Sales Engineers — The Five State Points Every AHU Quote Implies
The five psychrometric state points behind every AHU quote - outdoor, return, mixed, coil-leaving and supply air - with a worked example and the numbers a consultant checks.
From Selection to BIM — What a Clean DXF/IFC Hand-off Looks Like
What consulting engineers and BIM coordinators actually need from an AHU selection tool's DXF/IFC export — accurate dimensions, connection points, and no stale geometry.
Duct Connection Design — Damper Apertures, Velocities, and the Lost 50 Pa
How duct connection sizing, damper aperture position and deck-scoped routing quietly add 50 Pa to an AHU quote — and how to catch it before install.
An AHU Selection Software Alternative: The 3D-Native Approach
Evaluating an alternative to established AHU selection platforms like AHU Selection or airCalc++? How AirSelect3D's 3D-native design and live Eurovent compliance differ.
EN 13053 Casing Classes Explained: Thermal Transmittance, Bridging, Leakage
EN 13053 casing classes (T, TB, L, F) decode into real running costs - thermal bridging, air leakage and filter bypass explained with the class tables.
Heating Coil Selection — Rows, Fin Pitch and the Air-Side dP Trade-Off
How row count, fin pitch and tube velocity trade off against air-side pressure drop in AHU heating coil selection, with real circuit-sizing numbers.
A Kinetix Air Alternative for Europe: Why Eurovent Changes the Choice
Looking for a Kinetix Air alternative in Europe? How AirSelect3D compares on Eurovent ECP-05 and ErP compliance, European vendor engines and the 3D design model.
A Dogmatik AHU.SELECTOR Alternative: How AirSelect3D Compares
Evaluating a Dogmatik AHU.SELECTOR alternative? A fair, factual comparison with AirSelect3D on 3D design, certified vendor data, Eurovent ECP-05 and export formats.
Winter vs Summer Eurovent Class — Why AHUs Pass in January, Fail in July
Eurovent ECP-05-2026 grades fs-Pref for winter and summer separately. Here is why the same AHU casing can score A+ in heating mode and drop to class E in cooling mode.
AHU Selection Software Compared (2026): The Independent Platforms
An honest 2026 comparison of independent AHU selection software - AHU Selection, airCalc++, Dogmatik, Kinetix Air, ALTEC and AirSelect3D - by platform, 3D, vendor data and compliance.
AHU Technical Data Sheet — What Consultants Check (Free PDF Example)
The exact data a bureau d'études expects on an AHU technical data sheet — ErP 1253/2014, ECP-05-2026 class, EN 1886, acoustics — with a full 15-page example PDF to download.
Octave-Band Sound Power in AHUs — How LwA Totals Are Really Summed
How octave-band sound power levels are logarithmically summed and A-weighted into the LwA figure consultants ask for - with a full worked example.
Plate vs Rotary Heat Recovery: Efficiency, Leakage, Frost Strategy
Plate vs rotary heat recovery compared on EN 308 efficiency, EN 13053 leakage classes and frost risk — a climate-based selection guide for AHU sales engineers.
AHU Filter Classes After ISO 16890 — ePM1, ePM2.5 and ePM10 Explained
ISO 16890 replaced EN 779 - what ePM1, ePM2.5 and ePM10 really measure, and which filter class to specify for offices, hospitals and industry.
Face Velocity — the One Number That Sizes Your AHU Casing (and Your SFP)
Face velocity (v = q/A) drives casing size, coil selection, filter life and SFP in AHUs - target ranges per component and the real trade-offs.
Regulation (EU) 2024/1834: Fan Ecodesign Rules for AHUs, 2026–2027
Regulation (EU) 2024/1834 replaces 327/2011 - new fan efficiency minimums, fewer exemptions, and the 2026/2027 deadlines that decide AHU fan selection.
How to Choose AHU Selection Software in 2026 — a Buyer's Checklist for OEMs
A practical 2026 checklist for OEMs choosing AHU selection software - vendor data fidelity, live Eurovent/ErP compliance, 3D design and export formats.
Eurovent ECP-05-2026 and ErP for AHUs — the Compliance Guide Sales Engineers Actually Need
A practical guide to Eurovent energy classes, winter and summer fs-Pref ratios, ErP/NRVU requirements and what an auditable AHU dossier must contain in 2026.
Specific Fan Power (SFP) Explained — EN 16798, SFP_int and Why Your AHU Quote Depends on It
SFP = fan power / airflow in W/(m3/s). How SFP_int is calculated under EN 16798 and ErP, typical class values, and how to stay under the threshold.
Design your next AHU in 3D — in five minutes.
AirSelect3D runs certified manufacturer engines (Camfil, Ziehl-Abegg, eBM Papst, Friterm, Hoval) and ships an ErP-compliant Eurovent dossier with every selection.
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