1. Controlled Airflow Inlets NatVent project,WP3/A3.2 Willem de Gids NatVent TNO Building and Construction Research Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... An overview of the availability the performance and the application of inlets for natural supply of ventilation air and the consequences for indoor air quality and comfort

2. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Availability In different European countries there are several types of Controlled Air Inlets : Pressure Controlled Inlets (Fr, Nl) Humidity Controlled Inlets (Fr) Pollutants Controlled Inlets (Fr, Nl) Temperature Controlled Inlets (Se, Fi) Sizing Air Inlets: due to difference in philosophy on ventilation, European countries have different approaches to ventilation (see picture)

3. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Performance (1...) windtemperature 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) For most buildings pressure differences across air inlets are normally in the range of 1 to 20 Pa

4. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Performance (2...) principle of a constant airflow inlet A perfect constant airflow inlet gives a constant flow independent of the pressure difference. An airflow inlet could compensate for increased airflow from leakage.

5. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... window or window frame moving flap outside inside Performance (3...) example of a pressure controlled airflow inlet

6. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Performance (4...) Detailed measurements show that there are big differences between different ‘controlled’ inlets: different flowrate/capacity or size response pressure level 1, 5, 20 Pa or even peak shaving closing only in stormy weather response time control options passive/active control Example: see next slide…. 

7. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... France constant Netherlands 90 % Performance (5|) 2 pressure controlled air inlets ….

8. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Application of Pressure Controlled Inlets Mainly in dwellings (minority of the building stock) Newly developed inlets are to be used in office buildings Barriers: Price is a problem: a passive pressure controlled inlet costs about three times a normal inlet No obligation to use them. M ostly installed in problem dwellings or more expensive properties Future applications: a big increase is expected in office type buildings where comfort and energy savings are the driving factors.

9. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Assumptions: wind velocity 5 m/s temp. difference 10K openings 100 cm2 per person Integration (1...) Indoor Air Quality The figure show the relative performance of a mechanical ventilation system and air inlets under average weather conditions. The pressure controlled inlets have a positive effect on the IAQ.

10. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Integration (2|) Energy use Controlled air inlets can increase indoor air quality decrease the energy use for ventilation Energy saving may be of the order of 15 to 30m 3 of natural gas per person per year These savings are based on the assumption that inlets are not controlled, and are left open over night

11. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Possible Improvements Pressure Controlled Inlets Pressure controlled inlets could be used more widely than is the case at present.Also a number of technical developments are foreseen: Presence control Interaction with BEMS Sound attenuation Air cleaning or filtering Integration with ventilation system ….

12. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Interactive tool on IAQ/Energy evaluation (1...) 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 The program displays the input and output data over a schematic of the building (see on next slide….  ) The input contains: –components of the ventilation system  inlets / outlets / overflow / building leakage / –climatic data  wind speed / wind direction  outside temperature The output is graphical: –airflow, CO 2 conc, energy use for ventilation

13. NatVent Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More... Interactive tool on IAQ/Energy evaluation (2|) The NavIAQ program

14. More information... NatVent You can fin more information on: 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 The NavIAQ program in the presentation of the final products: Go back to the Main page and choose Final Products - The NavIAQ program You can fin more information on: 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 The NavIAQ program in the presentation of the final products: Go back to the Main page and choose Final Products - The NavIAQ program 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 ar32e301(1).exe in the directory \Installation 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 ar32e301(1).exe in the directory \Installation Controlled inlets Controlled inlets Back to “WP3” Back to “WP3” Availability Performances Application Integration Controlled airflow inlet Improvements IAQ tool IAQ tool More... More...