dBCAD places your battery yard on the real site in 3D and carries its sound, octave by octave, to every neighbouring home. Each result arrives with its margin to the night limit, the method behind it and the uncertainty under it.
Twelve 40-ft battery enclosures, two PCS skids and a 2.5 MVA transformer on open farmland near Marl, turned to follow the field. The nearest home stands 114 m from the centre of the yard.
ISO 9613-2 from every face of every unit to a 4 m grid across 600 × 600 m. At 22:00 the period turns to night and the limit at these homes falls to 40 dB(A).
Fifteen units, fifteen contributions at the worst home, each traced to the unit that makes it. The front row of enclosures leads, so that is where a change pays.
42.6 dB(A) at Wasserwerksweg 7, 2.6 dB over the night limit; the apartment block 1.8 over. Four of the other six meet it by 2.4 dB or less, and at the upper estimate the studio prints beside each level (P90), seven of eight are over. A single headline number would call six of them safe.
Move a unit and run it again. Every result keeps its method, its inputs and its uncertainty, and goes into the report your acoustician checks and signs.
ISO 9613-2 · nine octave bands · 4 m grid over 600 × 600 m · bright line = the 40 dB(A) night limit
Unit shares at the 4.0 m window, A-weighted · the total is their energetic sum
Exceeds the night limit at two of eight homes, by up to 2.6 dB. At the upper estimate (P90), seven of eight are over.
Limit 40 dB(A) · TA Lärm, zone WA (assumed) · ISO 9613-2, stated accuracy ±3 dB
A battery yard runs the same units through the day and the night. The rule that binds it is the one you measure in the dark, at 22:00, at the receptor the home is asleep behind.
The fans and the HVAC inside the enclosures run the same duty cycle at 02:00 as they do at 14:00. The PCS that convert DC to grid AC and the MV transformer that steps the voltage up for export are still on. A residential home is, in every jurisdiction dBCAD covers, quieter at night than the day. The two curves cross — and the night case is the binding one for the closest home.
A margin that does not exist at 02:00 cannot be designed in at 14:00.
Most redesigns do not come from a wrong method. They come from a noise finding that arrived late, after the design was already paid for. dBCAD takes the model to the receptor before the model is taken to the authority. Every home has its own line on a plan view, its own predicted level at night, and its own margin against the local night limit.
The example shows what happens when this view is taken seriously. Eight homes, one night period: Wasserwerksweg 7 sits 2.6 dB above the limit and the apartment block 1.8 dB. Four of the other six meet it by 2.4 dB or less, and at the upper estimate the studio prints beside each level, seven of eight are over. A single headline number would call six of them fine; the margin-versus-uncertainty view tells a different story.
The browser studio runs the real engine on every step. Each step is one decision a developer already has to make.
The noise field around the yard, isolines at 5 dB steps, every unit at true size on the pad, and the eight nearest homes. Hover a home to read its predicted level and its margin against the night limit.
What it is · the engine's plan view at receptor height 4.0 m, painted from the 4 m noise grid · the rule · TA Lärm, zone WA (assumed), night 22:00–06:00, facade, 0.5 m in front of the window · Example · Marl, North Rhine-Westphalia
ISO 9613-2 states its own accuracy as ±3 dB. The example's worst case exceeds the limit by 2.6 dB and a second home by 1.8 dB. The next four meet it by margins of 0.5, 1.6, 2.3 and 2.4 dB, all inside the method's stated window. A single number would have called eight homes fine. Every unit here runs on the generic library entry: source data assumed, no manufacturer measurement.
What it is · the same eight homes, now with the method's ±3 dB band drawn around each predicted level and the 40 dB(A) night limit as a horizontal reference · Example · Marl, North Rhine-Westphalia
The day limit is permissive; the night limit at the same home usually is not. Pick a home to read the predicted level against both limits at once.
Three principles, kept by every report the studio produces.
The studio reports a margin: predicted level against the limit at a named receptor, with the method and the uncertainty class. The developer's acoustician signs the report.
Every value sits beside its unit (dB(A), metres), its basis (facade or outdoor) and the source it came from — manufacturer data, library default or a measured octave band.
A is sound power per face (±1.5 dB), B is octave-band sound power (±2.5 dB), C is one dB(A) figure at a distance (±4 dB), U is the library default plus 3 dB and labelled as such.
The studio runs in the browser on the real engine. Request access to walk the example and pin your own site.