DA DB-HR / 1 – Guide for Acoustic Insulation Magnitudes and Requirements
The DA DB-HR / 1 is a technical supporting document (Documento de Apoyo) issued by the Ministerio de Fomento through the Secretaría General de Vivienda in Spain. This document specifically supports the Documento Básico DB-HR Protección frente al ruido, which is part of the Código Técnico de la Edificación (CTE). The December 2019 edition replaces previous versions from April and June 2016. While it provides technical guidance approved by the Ministry, it serves as a clarifying tool for the implementation of regulatory texts rather than carrying regulatory weight itself.
The scope of this guide is to establish a standardized procedure for the global assessment of acoustic insulation measurements for both airborne and impact noise. It provides the methodology to convert frequency spectrum data into a single-number descriptor, allowing for direct comparison with the requirements established in DB-HR. The document references several international standards, including UNE-EN ISO 16283 (Parts 1, 2, and 3) for in-situ measurements and UNE-EN ISO 717 (Parts 1 and 2) for the evaluation of acoustic insulation in buildings and building elements.
This document details specific calculation methods for airborne noise insulation between indoor enclosures, facade insulation based on dominant external noise sources, and impact noise levels. It includes normalized noise spectra for pink noise, automobile traffic, aircraft, and railway systems to ensure accurate acoustic characterization.
Airborne Noise Insulation Between Enclosures
The evaluation of airborne noise between indoor rooms starts with the spectrum of the standardized level difference, DnT (f), measured across one-third octave bands from 100 Hz to 5 kHz. The calculation of the single-number value follows specific formulas:
- Standardized level difference (DnT): Calculated using the mean sound pressure levels in the source and receiving rooms, adjusted by the reverberation time and a reference reverberation time (T0) of 0.5 seconds.
- Global insulation value (DnT,A): Obtained by applying an A-weighted normalized pink noise spectrum to the measured level differences.
- Rounding: The final value for DnT,A must be expressed as a rounded whole number following the criteria in UNE-EN ISO 717-1.
Airborne Noise Insulation of Facades
For facades, roofs, or floors in contact with outdoor air, the document defines the standardized level difference D2m,nT. The global assessment depends on the dominant type of exterior noise source identified at the site.
- Automobile traffic: Uses the LAtr,i spectrum for dominant road vehicle noise to calculate D2m,nT,Atr.
- Aircraft noise: Utilizes the LAav,i normalized spectrum for calculation when aircraft noise is the primary source.
- Railway noise: Applies the LAef,i spectrum for dominant noise from trains or railway stations to determine D2m,nT,A.
- Measurement position: The external sound pressure level is measured at a distance of 2 meters in front of the facade.
Impact Noise Insulation
Impact noise insulation is characterized by the standardized impact sound pressure level, L’nT (f), based on measurements performed according to UNE-EN ISO 16283-2.
- Frequency range: Measurements are taken in one-third octave bands between 100 Hz and 3150 Hz.
- Calculation formula: The level is adjusted using the receiver room's reverberation time relative to the reference value of 0.5 seconds.
- Single-number descriptor (L’nT,w): The final global value is determined and rounded to a whole number according to the procedures in UNE-EN ISO 717-2.
Frequently Asked Questions
What is the reference reverberation time used in calculations?
The reference reverberation time (T0) is set at 0.5 seconds for all standardized level difference calculations in this document.
How is the final acoustic insulation value rounded?
The final global insulation values must be expressed as rounded whole numbers, following the rounding rules defined in the UNE-EN ISO 717 standards.
Which noise spectrum is used for indoor airborne insulation?
The calculation of DnT,A for indoor enclosures uses an A-weighted normalized pink noise spectrum, with values ranging from -30.1 dBA at 100 Hz to -10.5 dBA at 5000 Hz.
At what distance from a facade should external measurements be taken?
External sound pressure levels for facade insulation (L1,2m) are measured at a distance of 2 meters directly in front of the facade.
What frequency bands are used for impact noise evaluation?
Impact noise is evaluated in one-third octave bands ranging from 100 Hz to 3150 Hz.
Does DA DB-HR / 1 have regulatory force?
No, as a Supporting Document (Documento de Apoyo), it serves as a technical aid for understanding and applying the DB-HR, but it does not have the status of a regulation or statute.
