Controlled Airflow Inlets Controlled airflow inlet Controlled inlets

Controlled Airflow Inlets Controlled airflow inlet Controlled inlets Nat. Vent project, WP 3/A 3. 2 Availability Willem de Gids Performances Application Integration Improvements IAQ tool More. . . An overview of l the availability l the performance and l the application of inlets for natural supply of ventilation air and the consequences for indoor air quality and comfort Back to “WP 3” Nat. Vent TNO Building and Construction Research

Availability Controlled airflow inlet Controlled inlets n In different European countries there are several types of Controlled Air Inlets : l Pressure Controlled Inlets (Fr, Nl) l Humidity Controlled Inlets (Fr) l Pollutants Controlled Inlets (Fr, Nl) l Temperature Controlled Inlets (Se, Fi) n Sizing Air Inlets: due to difference in philosophy on ventilation, European countries have different approaches to ventilation (see picture) Availability Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent

Performance (1. . . ) Controlled airflow inlet Controlled inlets n The purpose of a pressure controlled air inlets is to maintain a constant air flow independent of wind pressure and pressure differences due to buoyancy (stack effect) n For most buildings pressure differences across air inlets are normally in the range of 1 to 20 Pa Availability Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent wind temperature

Performance (2. . . ) Controlled airflow inlet principle of a constant airflow inlet Controlled inlets Availability Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent A perfect constant airflow inlet gives a constant flow independent of the pressure difference. An airflow inlet could compensate for increased airflow from leakage.

Performance (3. . . ) example of a pressure controlled airflow inlet Controlled inlets window or window frame Availability moving flap Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent inside outside

Performance (4. . . ) Controlled airflow inlet Controlled inlets n Detailed measurements show that there are big differences between different ‘controlled’ inlets: l different flowrate/capacity or size l response pressure level l 1, 5, 20 Pa or even peak shaving closing only in stormy weather l response time l control options l passive/active control n Example: see next slide…. Availability Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent

Controlled airflow inlet Controlled inlets Performance (5|) 90 % France constant Availability Performances Application Integration Netherlands Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent 2 pressure controlled air inlets ….

Application of Pressure Controlled Inlets Controlled airflow inlet Controlled inlets Mainly in dwellings (minority of the building stock) n Newly developed inlets are to be used in office buildings n Availability Performances n Application Integration l Price is a problem: a passive pressure controlled inlet costs about three times a normal inlet l No obligation to use them. Mostly installed in problem dwellings or more expensive properties Improvements IAQ tool Barriers: n More. . . Back to “WP 3” Nat. Vent Future applications: l a big increase is expected in office type buildings where comfort and energy savings are the driving factors.

Integration (1. . . ) Indoor Air Quality Controlled airflow inlet Controlled inlets Availability The figure show the relative performance of a mechanical ventilation system and air inlets under average weather conditions. n The pressure controlled inlets have a positive effect on the IAQ. n Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent Assumptions: • wind velocity 5 m/s • temp. difference 10 K • openings 100 cm 2 person

Integration (2|) Energy use Controlled airflow inlet Controlled inlets n Controlled air inlets can l increase indoor air quality l decrease the energy use for ventilation n Energy saving may be of the order of 15 to 30 m 3 of natural gas person per year n These savings are based on the assumption that inlets are not controlled, and are left open over night Availability Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent

Possible Improvements Pressure Controlled Inlets Controlled airflow inlet Controlled inlets n Availability Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent Pressure controlled inlets could be used more widely than is the case at present. Also a number of technical developments are foreseen: l Presence control l Interaction with BEMS l Sound attenuation l Air cleaning or filtering l Integration with ventilation system l ….

Interactive tool on IAQ/Energy evaluation (1. . . ) Controlled airflow inlet Controlled inlets n In the framework of this work package a special tool was developed to evaluate the IAQ (CO 2 -concentration) and Energy Use when using a ventilation system with different types of air inlets n The program displays the input and output data over a schematic of the building (see on next slide…. ) l The input contains: – components of the ventilation system w inlets / outlets / overflow / building leakage / – climatic data w wind speed / wind direction w outside temperature l The output is graphical: – airflow, CO 2 conc, energy use for ventilation Availability Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent

Controlled airflow inlet Interactive tool on IAQ/Energy evaluation (2|) Controlled inlets Availability Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent The Nav. IAQ program

Controlled airflow inlet Controlled inlets Availability More information. . . You can fin more information on: n Controlled Air Flow Inlets and the work carried out in the framework of Task 3. 2. in the document ‘ 3. 2_controlled air flow. pdf’ in the directory Reports Technological solutions n The Nav. IAQ program in the presentation of the final products: Go back to the Main page and choose Final Products - The Nav. IAQ program Performances Application Integration Improvements IAQ tool More. . . Back to “WP 3” Nat. Vent You can read and print pdf-files with the Acrobat® Reader ® 3. 0. Program. This program is free. Download it from the Acrobat web site: www. adobe. com OR run the installation file ar 32 e 301(1). exe in the directory Installation