Healthy, productive indoor climate Products and applications Unrestricted © Siemens 2021 siemens.
Contents 1 Purpose of this document ................................................................................................................................3 2 Why is a healthy, productive indoor climate so valuable? ..................................................................................4 2.1 Building occupant productivity.................................................................................................................4 2.2 Building occupant health and wellbeing ........
1 Purpose of this document This document is intended to give a first overview of the products and applications used to create a healthy, productive indoor climate. The target readership is the Siemens internal sales force and Siemens Solution Partners.
2 Why is a healthy, productive indoor climate so valuable? 2.1 Building occupant productivity Recent research studies highlight the large impact of indoor air quality (IAQ) on the performance of people. The control of carbon dioxide (CO2) plays a major role, providing an opportunity to increase measurable productivity by up to 18% on average and by a factor of 10 or more at CO2 levels often found in meeting rooms and classrooms (References 1, 2, 3, and 4).
Illness and employee absenteeism can be reduced significantly by monitoring and controlling humidity. Coughing and sneezing creates an aerosol of virus-filled droplets. Dry air provides optimal conditions for the viruses to survive. Controlling humidity to between 40% and 60% can reduce virus transmission by up to 70% (References 8, 9, and 10).
4 Control applications and targets (CO2, VOC, RH, PM2.5) In general, a variable air volume (VAV) system is needed to ensure a healthy, productive indoor climate, as the relevant climate parameters are controlled through ventilation. This is shown in the following table. It should be noted, however, that there are fan coil unit (FCU), chilled/heated ceiling and heat pump applications which also control relative humidity (RH) by switching an external humidification/dehumidification unit.
Building type Control parameters Selection Customer values Restaurants, kitchens CO2 VOC RH PM2.5 Standard Standard Standard Standard4 Guest experience, performance of staff Health and performance of staff Guest experience Health and performance of staff Hospital rooms, care homes CO2 VOC RH Standard Standard Standard Guest experience, performance of staff Fewer staff absences, better recovery rates Fewer staff absences, better recovery rates Retail stores CO2 VOC RH PM2.
6.3 Fine dust PM2.5 monitoring The approach to controlling PM2.5 (or PM10) fine dust air pollution is typically as follows: 1. Monitoring PM2.5 over a time period to assess the problem 2. If necessary, improving the air filters in the AHU (VAV system) 3. If the PM2.
7 Controlling indoor climate parameters for health and productivity 7.1 Product bundles – overview The table below shows the product bundles for controlling CO2, VOC, RH and PM2.5. CO2, VOC and RH can be controlled via VAV applications. Relative humidity can also be controlled via humidifier/dehumidifier in FCU and chilled/heated ceiling applications. PM2.5 is controlled by improving air filters (in AHU) and, if needed, by room air purification.
RH Product bundles (A to F) Benefits (D) FCU, chilled/heated ceiling • • • • via KNX room thermostat Easy application selection by DIP switch Increased occupant health/productivity Standalone or communicating (KNX) Can be integrated into BACS for increased energy efficiency and remote monitoring RDG165KN + external humidifier/dehumidifier PM2.5 (E) Control of PM2.5 by improved filtration (in AHU) PM2.5 (and CO2) (F) Control of PM2.5 & CO2 via PM2.
7.2 VAV control of CO2 and VOC (A) Desigo Room Automation with room sensors Room controller DXR2.. Sensors VAV control of combined CO2 and VOC • Supply and extract air control • External flow control for VAV with flow controller and diff. pressure sensor • Internal flow controller and diff.
(B) Desigo Room Automation with room unit and room sensor Room controller DXR2.. VAV control of CO2 and VOC • Supply and extract air control • External flow control for VAV system with flow controller and diff. pressure sensor • Internal flow controller and diff.
(C) KNX room thermostat RDG405KN VAV control of combined CO2 and VOC • Single-duct system • Optional: electric heater, radiator/floor heating, heating/cooling coil Built-in temperature sensor AQR2548NF + AQR2530NNW (or QPA2002) Analog IAQ output (DC 0…10 V) (higher value of VOC and CO2) Single-duct VAV system or AQR2576NF + AQR2532NNW T and CO2 only output, KNX LTE- or S-Mode Single-duct VAV system with radiator VAV compact controller GDB181.1E/KN, or GLB181.1E/KN or GDB181.1E/3, or GLB181.
7.3 FCU or chilled/heated ceiling: T, RH (D) KNX room thermostat RDG165KN Inbuilt sensors for T, RH and algorithm for humidity control Universal control: FCU, chilled/heated ceiling • For temperature and humidity control • Control sequences for heating and/or cooling, 1 or 2 stages • Dewpoint monitoring • Multifunctional inputs: key card contact, external sensor • Multifunctional inputs: window contact, presence detector, etc. • Interworking with KNX communicating sensors AQR.., QMX..
7.5 Control of PM2.5 and CO2 in individual rooms (F) Control of PM2.5 and CO2 via PM2.5 controller and external air purifier If improved filtering is insufficient to reach the desired IAQ, a further step is to purify the indoor air. One way to achieve this is by using individual room air filtration units. The sole purpose of these units is the purification of the air. The introduction of such units does not affect the control application of the conventional HVAC system. The PM2.
8 Products for a healthy productive indoor climate CO2 x x QSA2700D QFA…D x VOC RH QPA20xD RDF870KN RDG165KN RDG405KN QMX3.P35H/P38H QMX3.P74 8.1 Room units and sensors used for room climate monitoring x x PM2.5 x x x x x 8.2 Suitable room controller platforms The Siemens controller platforms that deliver the above applications are: 1. Desigo Room Automation offering (DXR2.. controllers1 and QMX3.. room units), and 2. KNX-communicating room thermostats RDF../RDG..
8.3 Room units and communicating room thermostats VAV room unit for T, IAQ and RH control QMX3.Pxx Features Mode selection Fan switch Setpoint adjuster Inbuilt temperature sensor Inbuilt humidity sensor Inbuilt CO2 sensor (only for QMX3.P7.. versions) Wall-mount Integration into DXR2..
8.4 Sensors CO2 sensors measure the concentration of CO2 in parts per million (ppm). Fresh outdoor air is around 400 ppm and indoor levels up to 1000 ppm are acceptable. There is no generally acceptable level of VOC as there is usually a mixture of volatile gases some of which are more dangerous than others. Siemens VOC sensors are sensitive to a broad range of oxidizing and reducing gases, giving an indicative measure. Siemens offers combined CO2/VOC sensors (AQR.., QPA.. and QPM..
Sensor selection Here are some rules to help with sensor selection: 1. An ideal choice for IAQ is one of Siemens’ combined CO2 and VOC sensors (AQR.., QPA.. or QPR..). The sensor element measuring the higher demand (be it CO2 or VOC) will determine the flow rate of fresh air. 2. Room or air duct sensors? In principle, IAQ can be measured either in the room itself or in the extract air duct. Room sensors enable the plant to be switched off completely, thus maximizing energy savings.
The following products DXR1.. and DXR2.. combine a Desigo room controller and a VAV compact controller in one hardware device. The DXR1.. is for HVAC only applications. The DXR2.. also covers room electrical applications such as lighting and shading control. BACnet IP VAV actuating room controller DXR1.E09PDZ.. DXR1.E04PDZ.. DXR1.E10PL.. DXR2.E10PL.. Communication (field bus) None KNX PL-Link KNX LTE KNX PL-Link KNX LTE-/S-Mode Torque (Nm) 5 10 10 0.8 1.5 1.
Examples of applications type A and B using actuating DXR2.. (A) IAQ and temperature control – room sensors (T, combined CO2, VOC) (B) CO2, VOC and temperature control – room unit (T, CO2) and room sensor (VOC) Advantage of KNX PL-Link communicating VAV compact controllers The KNX PL-Link communicating VAV compact controllers GDB181.1E/KN and GLB181.1E/KN enable more energy-efficient and other intelligent VAV control features.
Appendix 1: Indoor air quality (IAQ) – Combined CO2 and VOC sensors CO2 concentration is measured in parts per million (ppm). Fresh outdoor air is around 400ppm and indoor levels of up to 1000ppm are acceptable. However, there is much more to indoor air quality than just CO2 concentration. Volatile Organic Compounds1 (VOCs) are not detected by CO2 sensors, and yet are major contributors to the health problems associated with sick building syndrome.
Appendix 2: Integration of RDF../RDG.. (KNX) in Desigo For the purpose of monitoring, RDF../RDG.. (KNX) can be integrated into Desigo CC and Desigo CC Web Client via a KNX IP router or IP interface, as shown in the illustration below. RDF../RDG.. KNX room thermostats can also be integrated into Desigo primary via Desigo PX KNX (for more details, see the illustration below and Reference 15).
Appendix 3: Other indoor climate parameters – NO2, SO2, O3 The air quality index (AQI) is used as an overall guide to the level of air pollution. It is based on measured values of PM2.5, PM10, NO2, O3, SO2 and CO. So why do we monitor and control PM2.5, PM10, CO2 and VOC, but not NO2, SO2 and O3? CO2 and VOC are generated mainly inside buildings, while NO2, O3, and SO2 come mainly from outside, that is, from industrial processes and vehicles. PM2.5 and PM10.5 come from both indoor and outdoor sources.
Appendix 4: Tender texts The following are tender texts for the product bundles A, B, C and D (and their corresponding applications), detailed in Section 7. Product Bundle (A): VAV control via Desigo Room Automation with 2 room sensors Operation Operating modes Comfort The operating mode when the room is occupied must be Comfort mode. Pre-Comfort The operating mode when the room is unoccupied must be Pre-Comfort, allowing the room to quickly reach the comfort range upon changing to a Comfort mode.
detector reports occupancy, the room is occupied, and must be controlled to the occupancy temperature setpoint. Room equipment Temperature sensor This sensor should be wall-mounted and measure the room temperature. Air quality sensor (Combined CO2 and VOC) This sensor should be wall-mounted and measure CO2 and VOC levels. Its output signal should represent the higher of the two measurements.
fully open, the variable air volume (VAV) damper must control the supply air between min. and max. cooling to maintain the room temperature at the cooling setpoint. Extract air volume control – room pressure control (optional) Negative or positive room air pressure control must be accomplished by flow synchronization (air flow tracking).
Determine the operating mode Local Presence detector: A presence detector must influence the operating mode of the room temperature controller during occupancy. During this period, the operating mode must change to “Occupy” in the room when occupied and control for occupancy as per the temperature setpoint. If no one is in the room, the presence detector must switch to the operating mode for unoccupied with room temperature control for this state.
temperature very quickly. Based on the measured room temperature, the room temperature controller must calculate a setpoint for the supply air temperature at the discharge air outlet. When the room needs cooling, the supply air damper must control the supply air between min. and max. cooling to maintain the room temperature at the cooling setpoint. The room temperature must be acquired via a sensor located in the room unit or an extract air sensor in the duct.
Product Bundle (C): VAV control via KNX thermostat Operation Operating modes Comfort The operating mode when the room is occupied must be Comfort. Economy Economy must be the operating mode in a room that is unoccupied for a longer period (e.g. planned night setback). Protection The operating mode when the building is unoccupied (for example, during holiday periods) for any extended period of time must be Protection.
Air quality sensor (Combined CO2 and VOC) This sensor should be a wall-mounted and measure CO2 and VOC levels. Its output signal should represent the higher of the two measurements. Presence detector This sensor should be ceiling-mounted and detect slight movements, such as a person typing on a keyboard.
Product Bundle (D): FCU, chilled/heated ceiling via KNX thermostat Operation Operating modes Comfort The operating mode when the room is occupied must be Comfort. Economy Economy must be the present operating mode in a room that is unoccupied for a longer period (e.g. planned night setback). Protection The operating mode when the building is unoccupied (for example, during holiday periods) for any extended period of time must be Protection.
Presence detector This sensor should be ceiling-mounted and detect slight movements, such as a person typing on a keyboard. Control sequences Temperature control The thermostat acquires the room temperature via the built-in sensor and maintains the setpoint by delivering actuator control commands to the heating and/or cooling equipment. Outputs are available to control: • Fan: 1-speed, 3-speed fan or DC 0...
External references (1.) Re-thinking Organizational Savings through HVAC, REHVA Journal, April 2018 (2.) Is CO2 an indoor pollutant? Direct effects of low-to-moderate concentrations on human decision-making performance. Satish, Mendell, et Al.; Environmental Health Perspectives, Volume 120, No12, December 2012 (3.) Allen et Al.
Siemens reference documents (13.) RDF870KN fine dust controller sales presentation (not yet available in Step database) (14.) RDF870KN fine dust controller technical presentations (not yet available in Step database) (15.) Integration of RDF/G into Desigo (Step reference EN: A6V11322660; Step reference DE: A6V11322659) (16.) Desigo room automation applications – see HIT tool: https://hit.sbt.siemens.com/RWD/app.aspx?RC=HQEU&lang=en&MODULE=Application& ACTION=ShowGroup (17.
Glossary AHU Air handling unit AQI Air quality index BACS Building automation and control system CO2 Carbon dioxide ESP Electrostatic precipitator FCU Fan coil unit HEPA High-efficiency particulate air IAQ Indoor air quality (combined measure of CO2 and VOC levels) NO2 Nitrogen dioxide PM2.5 Particulate matter (less than 2.
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