1 Meeting ASHRAE Fundamentals, Standard 55 & 62.1 with Chilled Beams Displacement Ventilation.

2 ASHRAE Standard Space Ventilation for Non-residential Occupancies Ventilation for Acceptable Indoor Air Quality Classifies occupied spaces Sets ventilation requirements based on size and occupancy Sets guidelines for demand control ventilation

3 ASHRAE Standard Space Ventilation for Non-residential Occupancies Conventional Method Ventilate the space according to ASHRAE Use Ventilation Rate or IAQ Procedure to determine OA requirements using table 6-1

4 ASHRAE Standard Space Ventilation for Non-residential Occupancies Conventional Method Ventilate the space according to ASHRAE Use Ventilation Rate or IAQ Procedure to determine OA requirements using table 6-1 Make Corrections for Zone Air Distribution Effectiveness using Table 6-2

5 ASHRAE Standard Space Ventilation for Non-residential Occupancies Conventional Method Ventilate the space according to ASHRAE Use Ventilation Rate or IAQ Procedure to determine OA requirements using table 6-1 Make Corrections for Zone Air Distribution Effectiveness using Table 6-2 Make Corrections for Multiple- Zone Recirculating System using Table 6-3 Z p =V oz /V pz

6 ASHRAE Standard Space Ventilation for Non-residential Occupancies Conventional Method Ventilate the space according to ASHRAE Use Ventilation Rate or IAQ Procedure to determine OA requirements using table 6-1 Make Corrections for Zone Air Distribution Effectiveness using Table 6-2 Make Corrections for Multiple-Zone Recirculating System using Table 6-3 Z p =V oz /V pz

7 ASHRAE Standard Space Ventilation for Non-residential Occupancies Conventional Method Our Goal is to Reduce the Amount of Treated Air Traveling Through the Building 62.1 Dynamic Reset a.k.a. CO2 Ventilation How does the Outdoor Air know where to go?

8 ASHRAE Standard Space Ventilation for Non-residential Occupancies Goal: Reduce the Amount of Conditioned Air Traveling Through the Building -So how else can we reduce the treated air??? Displacement 18“ x 18“ Air Duct 1“ diameter Water Pipe Chilled Water (above the dew point)

9 ASHRAE Standard Space Ventilation for Non-residential Occupancies Goal: Reduce the Amount of Conditioned Air Traveling Through the Building -So how else can we reduce the treated air??? Displacement Displacement TerminalQLI Disp. Term w/ CoilActive Chilled Beam Chilled Water (above the dew point)

10 ASHRAE Standard Space Ventilation for Non-residential Occupancies Ideally get to a… DOAS The system is simplified. Constant Volume No return air. One Step Further… DOAS w/ CO2 Sensor The Fresh Outside Air goes where it’s need. More Complicated due to VAV

11 Implementing ASHRAE Standard 62.1 While Not Abusing ASHRAE Standard 55 & Fundamentals Near/Adjacent Zone No comfort zone High Airflow / Draft

12 ASHRAE Standard Thermal Comfort Guide Defines “Occupied Zone” Factors affecting thermal comfort –Metabolic rate –Clothing (insulation) –Air temperature and speed –Radiant effects –Humidity Defines acceptable conditions Goal is occupant satisfaction levels 80% or higher

13 ASHRAE Standard Occupied Zone Defines “Occupied Zone” Occupied zone definition –Not within two (2) feet of a wall –Between the floor and the head level of the predominant space occupants

14 ASHRAE Standard Thermal Comfort Guide Defines “Occupied Zone” Factors affecting thermal comfort –Metabolic rate –Clothing (insulation) –Air temperature and speed –Radiant effects –Humidity

15 Occupant Thermal Comfort Basic principles SHG = Metabolic Rate Clothing Convective transfer to surrounding airRadiant transfer to cooler surfaces Dependent on temperature of surfaces Independent of air conditions Dependent on orientation of surfaces Effected by air speed Dependent on air conditions Thermal comfort achieved when heat out is equal to heat generated

16 ASHRAE Standard Thermal Comfort Guide Defines “Occupied Zone” Factors affecting thermal comfort Defines acceptable conditions

17 ASHRAE Standard Cooling Operation Comfort Range Operative Temperature, °F Humidity Ratio, Lbs Water per Lb Dry AirSpace Dew Point Temperature, °F 50%RH 45%RH 55%RH 60%RH Cooling Operation Comfort Window Assumes 1.0 Clo, 40% Tu and ≤ 40 FPM mean velocity

18 ASHRAE Standard Thermal Comfort Guide Defines “Occupied Zone” Factors affecting thermal comfort Defines acceptable conditions Goal is occupant satisfaction levels 80% or higher

19 Return Ankle Level Displacement Supply Air Near Zone Neck Level Thermal Plume ASHRAE Standard & Fundamentals Lets Start with Displacement Ventilation

20 Near/Adjacent Zone Adjacent zone is defined as the region adjacent to the terminal discharge in which terminal velocities exceeding 0.2 m/s (40 FPM) may be found that are 71F or below. It is indicated by the dimension L 0.2 as shown. To avoid draft complaints, stationary space occupants should not be located within this region. No comfort zone L 0.2 ASHRAE Standard & Fundamentals

21

22 Comfort Chart – Ankle Region

23 Comfort Chart – Neck Region

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25 So why is there such a difference between manufacturers? Nozzles VS Perforated Adjacent Zone Effect

26 Include the Max. Allowable Adjacent Zone in the Schedule

27 ASHRAE Standard & Fundamentals Now Lets Look at Active Chilled Beams Discharge to Room Ducted primary air

28 Room sees two slot linear diffusers, nothing more! ASHRAE Standard & Fundamentals What is an Active Chilled Beam? It‘s a Diffuser!

29 ASHRAE Standard Defines “Occupied Zone” Factors affecting thermal comfort –Metabolic rate –Clothing (insulation) –Air temperature and speed –Radiant effects –Humidity Defines acceptable conditions Goal is occupant satisfaction levels 80% or higher Now Lets Look at Active Chilled Beams

30 Mixed Air Systems OCCUPIED ZONE T 150 T 100 T 50 T 100 T 150 ASHRAE Standard

31 ASHRAE Fundamentals Cooling Operation Comfort Range Acceptable to 80% Dissatisfaction Criteria 5% to 15% recommended limit 15% for draft (mixed flow)

32 Part 1 – Chilled Beam The primary air via a diffuser (Beam) Provides fresh air requirement Controls temperature Controls humidity Room Airflow Active Chilled Beams Mixed Room Air Distribution

33 Part 1 – Chilled Beam What does a diffuser do? Delivers fast cold (or hot) air to the space It directs the discharge Makes use of the Coandă effect Reduced velocity by mixing Changes temperature by mixing What does a diffuser do? Delivers fast cold (or hot) air to the space It directs the discharge Makes use of the Coandă effect Reduced velocity by mixing Changes temperature by mixing Room Airflow Active Chilled Beams Mixed Room Air Distribution

34 Room Airflow Part 1 – Chilled Beam Beam vs. diffuser Increases volume, Example: assume 60% water 40% air 100 cfm by diffuser, 40 beam but with induction ratio of say 4:1, = total air discharged is 40 x 4 + Original 40 = 200 cfm If we work on 1cfm/SF and room Height of 10’ 100 cfm = 6 ac/hr, 200 cfm = 12 ac/hr (room air movement) The increased discharge temperature helps but the higher volume throws further in a ‘more active space’. Beam vs. diffuser Increases volume, Example: assume 60% water 40% air 100 cfm by diffuser, 40 beam but with induction ratio of say 4:1, = total air discharged is 40 x 4 + Original 40 = 200 cfm If we work on 1cfm/SF and room Height of 10’ 100 cfm = 6 ac/hr, 200 cfm = 12 ac/hr (room air movement) The increased discharge temperature helps but the higher volume throws further in a ‘more active space’. Active Chilled Beams Mixed Room Air Distribution

35 ASHRAE Standard

36 Selection Software 4 or 2 pipe beam

37 Input Beam Length and Nozzle Type Selection Software Input Primary air, Room and CWS Temperatures Input Water Flow Rate (s)Input Primary Airflow RateInput Beam Mounting Details for Local Velocity Predictions Output: Sensible from Water, Air and Total Output Waterside, Airside Pressure drop and noise Output: Sensible from Water, Air & Total

38 Room Airflow Part 1 – Chilled Beam Beams must be selected for comfort, not just BTU’s The selection programs will also show you that as you increase the cooling but maintain the cfm volume, the throw increases. Beware of any proposition that half the number of beams for a given design when no throw data or statement on comfort is offered. Beams must be selected for comfort, not just BTU’s The selection programs will also show you that as you increase the cooling but maintain the cfm volume, the throw increases. Beware of any proposition that half the number of beams for a given design when no throw data or statement on comfort is offered. Active Chilled Beams Mixed Room Air Distribution

39 Active Chilled Beam Velocities ASHRAE and AHRI working to establish testing and rating standards –Sensible cooling capacities –Aerodynamic performance (throw data) –Acoustical performance Many manufacturers do not catalog throw or velocity data One proposes selections with discharge airflow rates > 100 CFM/LF –Results in T 100 values of 20 to 25 feet –Requires minimum diffuser separation of 50 to 60 feet for ADPI ≥ 80

40 ASHRAE Fundamentals & Standard 55

41 ASHRAE Fundamentals & Standard 55

42 Designing Chilled Beam Systems for Thermal Comfort Thank You!