Air Distribution for Comfort. David Pich P.E. LEED AP Director of HVAC Technology

Transcription

1 Air Distribution for Comfort David Pich P.E. LEED AP Director of HVAC Technology

2 What You Will Learn ASHRAE Standards for Comfort & IAQ Types of Comfort Cooling Systems Fully Mixed Partially Mixed Fully Stratified ASHRAE & AHRI Standards for Testing and Sound

3 Standards TM ASHRAE Standard 55 Thermal Comfort ASHRAE Standard 62.1 Ventilation for Acceptable IAQ ASHRAE Standard 70 Diffuser Testing AHRI 885 Estimating Sound for Diffuser and Terminal Units

4 Graphic Comfort Zone ( ) Data based on ISO 7730 And ASHRAE Std. 55 Met Rate Upper Recommended Humidity Limit humidity ratio DPT < 62.2 F 1.0 Clo 0.5 Clo Met Rate Operative Temperature F

5 ASHRAE Std. 55 Occupied Zone

6 ASHRAE Standard Table 6 2 Zone Air Distribution Effectiveness Ez Ceiling supply of cool air 1.0 Ceiling supply of warm air with floor return 1.0 Ceiling supply of warm air >15 F above space and ceiling return. 0.8 Ceiling supply warm air <15 F above space, T150 within 4.5 AFF 1.0 Floor supply cool air, ceiling return low velocity (DV) 1.2 Floor supply of cool air with T50 < 4.5 AFF (UFAD) Floor supply of cool air with T50 > 4.5 AFF (UFAD) Floor supply of warm air with ceiling return 0.7

7 2015 Application Chapter 57 Fully Stratified Partially Mixed Fully Mixed Displacement Under Floor Air Distribution G.R.D.

8 Fully Mixed Air Distribution

9 Partially Mixed Air Distribution

10 Fully Stratified Air Distribution Return

11 Diffuser Testing Diffusers tested per ASHRAE Standard 70

12 Sound Tests Diffusers and grilles Supply sound Return/exhaust sound

13 Sound Path Estimation AHRI Standard 885 provides sound path and attenuation values for Lined duct Ceiling materials Elbows Flex duct Etc

14 Sound Path Estimation D C SOUND POWER L w C =Casing Radiated and Induction Inlet O D O =Discharge Sound =Outlet Generated Sound

15 Sound Power vs Sound Pressure Sound power is the total sound energy produced Sound pressure is the sound level that results after some sound energy is lost to the environment If 80 db is produced but only 70 db is measured, the difference is a 10 db room effect or attenuation

16 The Decibel (db) The decibel(db) is measured against a frequency and averaged into octave bands Octave Band Designations Center Frequency Band Designation

17

18 Both tones are equally loud

19 NC Chart OCTAVE BAND LEVEL _ db RE MICROBAR APPROXIMATE THRESHOLD OF HUMAN HEARING K 2K 4K 8K MID - FREQUENCY, HZ NC-70 NC-60 NC-50 NC-40 NC-30 NC-20

20 For High Frequencies 1 db 3 db 5 db 10 db 20 db not noticeable just perceptible noticeable twice as loud four times as loud

21 NC Chart OCTAVE BAND LEVEL _ db RE MICROBAR APPROXIMATE THRESHOLD OF HUMAN HEARING K 2K 4K 8K MID - FREQUENCY, HZ NC-70 NC-60 NC-50 NC-40 NC-30 NC-20

22 For Low Frequencies 3 db noticeable 5dB 10 db twice as loud four times as loud

23 NC Plot NC rating given is NC-45 since this is highest point tangent to an NC curve NC Octave Band Level db RE Microbar NC-60 NC NC NC Approximate threshold of human hearing 10 NC K 2K 4K 8K MID - FREQUENCY, HZ

24 Decibel Addition To add two decibel values: 80 db + 74 db

25 Decibel Addition To add two decibel values: 80 db + 74 db 154 db (Incorrect)

26 Decibel Addition Correction To Be Added To Higher Value (db) Difference In Decibels Between Two Values Being Added (db) To add two decibel values: 80 db - 74 db = 6 db Difference in Values: 6 db From Chart: Add 1.0 db to higher Value 80 db + 1 db 81 db (Correct)

27 Source Multiplication Equation for sound power changes = 10logn 1 Fan on vs. 2 Fans on n=2 Add 3 db 1 Fan on vs. 4 Fans on n=4 Add 6 db 1 Fan on vs. 10 Fans on n=10 Add 10 db 1 Fan on vs. 100 Fans on n=100 Add 20 db 50 Fans on vs. 100 Fans on n=2 Add 3 db

28 Proximity To Sound Sources Would you really expect to hear 100 fans running at the same time? Properly selected diffusers shouldn t be heard from more than 10 feet away Although there may be multiple diffusers in a space, it s unlikely that more than one or two are within 10 feet of an occupant We would only expect to be able to hear a 10 foot section of continuous linear diffuser from any single location

29 Catalog Diffuser NC Values Diffuser NC values are based on a 10 db room effect deduction in each octave band Typical medium office with 8 10 ft high lay in ceiling, commercial carpet, sheetrock walls, and some office furniture 10 db is a reasonable room effect deduction for the critical octave bands Critical octave bands are 4 th (500 Hz), 5 th (1000 Hz), and 6 th (2000 Hz)

30 Typical NC Levels Conference Rooms < NC30 Private offices < NC35 Open offices = NC40 Hallways, utility rooms, rest rooms < NC45 NC should match purpose of room Difficult to achieve less than NC30 Select diffusers for NC20 25 (or less)

31 Sound Effects RP 1335 No Damper With OBD Standard de de de

32 Diffuser Installation Locate balancing dampers at branch takeoff Keep flexible duct bends as gentle as possible Flex duct is a great attenuator of upstream noise sources Keep duct velocities as low as possible But over sizing can result in higher thermal loss

33 Unexpected Results Higher radiated sound levels No ceiling Exposed ductwork Bounded ceiling plenums Reduced plenum height

34 Unexpected Results Higher discharge sound levels Unlined ductwork Terminal units close coupled to diffusers No flex duct Smaller rooms

35 NC Plots Octave Band Level_ db RE Microbar Approximate threshold of human hearing NC-70 NC-60 NC-50 NC-40 NC-30 NC-20

36 Air Diffusion Performance Index

37 ADPI & Comfort Air Diffusion Performance Index Statistically related the space conditions of local or transverse temperatures and velocities to occupants thermal comfort ADPI >= 80 is considered acceptable Effective draft temperature = (t x t c ) 0.07(V x 30) % of points where 3<= <= +2 = ADPI Velocity below 70 fpm

38 ADPI The grey area represents 3<= <= +2 You can vary temperature or velocity to maintain comfort 15 fpm = 1 F

39 Characteristic Room Length L Area Conditioned By Diffuser

40 ADPI Selection Range 40 (1 cfm/sq.ft.)

41 ADPI Selection Illustration Point A ADPI Min ADPI Min Max x20 Room 400 cfm = 1 cfm/sq ft Characteristic Length = 10 Therefore, look for T50 = 12 feet at 400 cfm (Max VAV) Check Turndown point at.6 T50/L (Min VAV) Set constant volume systems at Point A. T50/L

42 Recommended ADPI Ranges for Outlets Outlet T 50 /L Range Calculated T 50 & L Data Sidewall Grilles L T Ceiling Diffusers Round Pattern TMR, TMRA, TMS Ceiling Diffusers Cross Pattern PSS, TDC, Slot Diffusers ML, TBD, LL1, LL L T 50 L T L T Light Troffer Diffusers LTT, LPT Sill & Floor Grilles All Types L T L T

43 Plaque Diffuser ADPI Model OMNI

44 Perforated Diffuser ADPI Model PSS

45 Questions?

46 Air Distribution Applications David Pich P.E. LEED AP Director of HVAC Technology

47 What You Will Learn Types of Comfort Cooling Systems Fully Mixed Cooling Perimeter Applications (Overhead) Fixed Deflection Auto Changeover

48 Fully Mixed Air Distribution

49 Air Patterns & Cooling Jet Performance

50 Radial Pattern Air Flow Patterns Shorter throw More induction Not Recommended for heating

51 Radial Pattern Diffusers

52 Directional Pattern Longer throw Increased drop Air Flow Patterns

53 Directional Pattern Diffusers

54 Thermal Image Directional Flow 4-way pattern, 4 separate jets, longer throws

55 High Induction Outlet Nozzles for Rapid Mixing 55

56 Thermal Image High Induction Modified circular pattern with several distinct air jets

57 Why is 150 FPM Significant? Isovel Temperature Independent Throw same for Heat and Cool. Used by Standard 62.1 heating selection procedure

58 How Do We Convert Isothermal Data? Then 100 FPM

59 How Do We Convert Isothermal Data? And then 50 FPM

60 Mapping Throw

61 Mapping Throw Cooling

62 Throw Relationships Some general rules of thumb Isothermal 150 FPM = 150 FPM cooling or heating 100 FPM = 50 FPM cooling free jet 100 FPM = 100 FPM cooling with walls

63 Open Ceiling Designs What happens when you have an open ceiling design? Internal Coanda Pocket

64 Ceiling Independent Below Ceiling

65 Open Plan Office If the diffuser is mounted on an exposed duct, the throw values are 70% of those listed in the tables.

66 Ceiling Dependent Below Ceiling

67 Ceiling Obstructions Angle between kicker and the obstruction should be less than 15 o or the jet will drop excessively

68 Colliding Air Streams What happens when air streams collide?

69 Locating the Return Intake Return Intake return intake affects only the air motion within its immediate vicinity Even natural convection currents will overcome the draw of the intake

70 Temperature Differential and Short Circuiting Vo = 1000 fpm Short Circuit = 15% Vx = 150 FPM t = 20ºF t = 150/1000*20 Temp. Diff. = 3 ºF

71 Duct Mounted Supply Grilles Duct Mounting Velocity & Pressure

72 Effects of Cooling cfm 600 fpm 27

73 Throw vs. Drop with 20 Cooling Distance To Ceiling Upward Projection Spread Throw Distance Drop Distance Fig Below Fig. 11 No Ceiling Fig Below Fig.13 No Ceiling Fig Below Fig. 15 No Ceiling

74 Linear Slot Performance What about Performance of Linear slots? Table is based on one active length Maximum length of 10 continuous airflow Maximum length of 10 sound Length,Ft Throw Correction NC Correction

75 Open Bay

76 Cafeteria

77 Transit Center

78 Retail Spaces

79 Book Store

80 Large Atriums

81 Arenas & Churches

82 Work Out Facility

83 Perimeter Applications Vertical Projection Sills & Soffits Perimeter Applications

84 ASHRAE Standard Table 6 2 Zone Air Distribution Effectiveness Ez Ceiling supply of cool air 1.0 Ceiling supply of warm air with floor return 1.0 Ceiling supply of warm air >15 F above space and ceiling return. 0.8 Ceiling supply warm air <15 F above space, T150 within 4.5 AFF 1.0 Floor supply cool air, ceiling return low velocity (DV) 1.2 Floor supply of cool air with T50 < 4.5 AFF (UFAD) Floor supply of cool air with T50 > 4.5 AFF (UFAD) Floor supply of warm air with ceiling return 0.7

85 Estimating Downward Projection Chart provides vertical throw at 50 fpm for heating and cooling with the same diffuser 1000 fpm Typically, cfm and jet velocity are known 1000 cfm

86 Sills & Soffits Soffits cause air to turn up prematurely Aim air under the soffit to hit the glass or cold wall Sills deflect cold air into the room Sill height sets the stratification layer height

87 Rolling a Room Only for closed offices High air flow outlets are necessary (high induction is required) Select T50 at 1.5 times the length of the room plus the height Must not be obstructions in the path of the air stream Must be a complete wall (no cubicle type walls)

88 50/50 throw pattern is the best compromise for both heating and cooling Half of the air is always directed in the wrong direction T 150 to 4.5 AFF Max Δt = 15 F ASHRAE Standard 62.1 Typical Solution

89 Auto Changeover Diffuser Solution Diffuser Cooling Air flow does not pause in intermittent pattern to cause sustained drafts pop action of air flow pattern. Heating Sill Window

90 Actuating Between Cooling and Heating

91 Auto Changeover vs. Fixed Pattern Heating Mode Improved Room Temperature Response Fixed Air Pattern vs. Changing Air Pattern 100% Vertical Heating Shaded area represents Energy/Comfort Improvements Heating Air Flow divided 50% - 50%

92 Comfort Economics ASHRAE Journal, June 2008

93 Comfort Air Distribution The ASHRAE 2013 Fundamentals handbook, Chapter 20, 2016 Systems & Equipment and 2015 Applications handbook Chapter 57 provides guidance on diffuser selection. Select throw at Max. & Min. to meet ADPI guidelines. It cost less for install a good design than to replace a bad design.

94 Questions?

95 Terminal Units David Pich P.E. LEED AP Director of HVAC Technology

96 What you will learn Types and Applications Single duct Dual duct Exhaust Bypass Series fan powered Parallel fan powered Standards and Certification ASHRAE 130 AHRI 880 AHRI 885 AHRI 410 NEC UL ETL

97 What you will learn Features and Options Inlet sensors Dampers Liners Coils Controls Motors Filters Sizing and Selecting Inlet ducts Fans Electric coils Hot water coils

98 What you will learn (cont.) Installation Hanging methods Orientation Electrical Inlet conditions Discharge ductwork

99 Terminal Units Types and Applications

100 Single duct VAV Most common type Cold primary air (55 F) from AHU Serves interior spaces Provides ventilation (per ASHRAE 62.1) Modulates between design cooling (cfm) and minimum ventilation (cfm) to maintain room temperature setpoint using pressure independent control

101 Single duct CAV Same unit as single duct VAV, but controls are set to a single airflow rate (cfm) and no room sensor is required Receives conditioned air from an AHU or ventilation air from a DOAS Provides critical environment ACR s (per ASHRAE 170) and/or provides ventilation (per ASHRAE 62.1) Maintains constant airflow (cfm) through pressure independent control

102 Single duct VAV with heat Same unit as single duct VAV but controls a radiant panel or baseboard heater Cold primary air (55 F) from AHU Serves perimeter spaces Provides ventilation (per ASHRAE 62.1) Modulates between design cooling (cfm) and minimum ventilation (cfm) to maintain room temperature setpoint using pressure independent control

103 Single duct VAV with reheat Same unit as single duct VAV but includes either an electric or hydronic heating coil Cold primary air (55 F) from AHU Serves perimeter spaces Provides ventilation (per ASHRAE 62.1) Modulates between design cooling (cfm) and minimum ventilation (cfm) to maintain room temperature setpoint using pressure independent control and activates heat as necessary

104 Single duct CAV with reheat Same unit as single duct VAV with reheat, but controls are set to a single airflow rate (cfm) Room sensor only controls heater Cold primary air (55 F) from an AHU Provides critical environment ACR s (per ASHRAE 170) and/or provides ventilation (per ASHRAE 62.1) Maintains constant airflow (cfm) through pressure independent control but changes the air temperature to maintain room temperature setpoint

105 Single duct VAV with autochangeover Same unit as single duct VAV but includes inlet mounted temperature sensor Cold (55 F) and hot (90 F) primary air from AHU Serves interior and perimeter spaces Provides ventilation (per ASHRAE 62.1) Modulates between design maximum (cfm) and minimum ventilation (cfm) to maintain room temperature setpoint using pressure independent control

106 Bypass Also called dump boxes Used with CAV air handlers Responds to thermostat call for more/less airflow Unwanted airflow gets directed to return Obsolete

107 Exhaust terminals Requires different unit configuration to keep pressure drop low Typically works in tandem with a CAV with reheat unit Serves critical environment spaces that require pressurization (per ASHRAE 170) Positive room pressure creates protective environment Negative room pressure creates airborne infectious isolation (AII) room Can either control room pressure directly or by offset from supply volume

108 Exhaust terminals Don t use standard single duct VAV Contractors get confused They get installed backwards Inlet sensor facing wrong direction Inlet sensor downstream from damper It s a mess!

109 Dual duct terminals Different designs for different mixing requirements Non Mixing Standard Mixing High Mixing

110 Mixing ratios Standard mixing ratio = 1:10 For every 10 F of T between hot and cold supply temperatures, there will be less than 1 F of variation across the discharge duct at a point 4 ft downstream High mixing ratio = 1:20 For every 20 F of T between hot and cold supply temperatures, there will be less than 1 F of variation across the discharge duct at a point 4 ft downstream

111 Dual duct VAV (non mixing) Least common type, rarely used Cold (55 F) and hot (90 F) primary air from AHU Provides ventilation (per ASHRAE 62.1) No simultaneous heating/cooling Modulates between design heating/cooling (cfm) and minimum ventilation (cfm) to maintain room temperature setpoint using pressure independent control

112 Dual duct VAV (mixing) Most common type Cold (55 F) and hot (90 F) primary air from AHU Serves interior or exterior spaces Provides ventilation (per ASHRAE 62.1) High comfort, high operating cost Centralized equipment Modulates between design heating/cooling (cfm) and minimum ventilation (cfm) to maintain room temperature setpoint using pressure independent control

113 Dual duct CAV Very common type Cold (55 F) and hot (90 F) primary air from AHU Serves critical environment spaces Provides ventilation (per ASHRAE 62.1 and ASHRAE 170) Modulates between design cooling (cfm) and minimum ventilation (cfm) to maintain room temperature setpoint using pressure independent control

114 Fan powered terminals Series fan powered Parallel fan powered

115 Series fan powered Most common type in tall office buildings Can provide constant air motion Near constant sound levels Cold (55 F) air from AHU Pulls free heat from ceiling return plenum Additional heat (electric or hydronic) at discharge Can be ducted to return air grille (healthcare applications) Very low inlet pressure requirements Can run unit fan to maintain night setback temps without AHU Dynamic fan sequences can track room loads

116 Series fan powered Advantages Improved room air motion due to constant air changes Constant sound level Reduced inlet pressure requirement Low noise options Disadvantages Fan runs continuously Fan must handle design cooling airflow

117 Parallel fan powered Most common type in smaller buildings and warmer climates Fan is off during cooling mode Receives cold (55 F) air from AHU Fan energizes for heating mode Pulls free heat from ceiling return plenum Additional heat (electric or hydronic) at discharge, hydronic usually on induction port Higher inlet pressure requirements Can run unit fan to maintain night setback temps without AHU

118 Parallel fan powered Advantages Fan handles heating design airflow only Fan only runs during heating Very quiet during cooling Disadvantages Modulating sound level Varying airflow on diffusers Air leakage

119 Series vs. Parallel Which fan powered unit is more energy efficient? ASHRAE RP 1292 Looked at the entire HVAC system and building operation Parallel efficiency reduced due to primary air leakage Roughly equal when properly sized and applied Only looked at PSC motors Consortium report New project to look at ECM units Series with ECM was a clear winner

120 Terminal Units Standards and Certification Randy Zimmerman Chief Engineer

121 ASHRAE 130 Laboratory Methods of Testing Air Terminal Units Air pressure drop Pressure independence Casing leakage Damper leakage Flow sensor Temperature mixing Condensation Fan curves Radiated sound Discharge sound Exhaust sound

122 Sound Tests VAV terminals Radiated sound Discharge sound

123

124 For Low Frequencies 3 db noticeable 5dB 10 db twice as loud four times as loud

125 Both tones are equally loud

126 NC Plot NC rating given is NC-45 since this is highest point tangent to an NC curve NC Octave Band Level db RE Microbar NC-60 NC NC NC Approximate threshold of human hearing 10 NC K 2K 4K 8K MID - FREQUENCY, HZ

127 AHRI 885 Procedure for Estimating Occupied Space Sound Levels in the Application of Air Terminals and Air Outlets Radiated sound path Discharge sound path Appendix E provides standard attenuation values to be used when presenting NC values in catalogs

128 Sound Path Estimation AHRI Standard 885 provides sound path and attenuation values for Lined duct Ceiling materials Elbows Flex duct Etc

129 Catalog Radiated NC Values Terminal unit radiated NC values based on standard assumptions from AHRI 885 Appendix E 3 ft deep ceiling plenum with unbounded sides 5/8 thick, 20 lb/ft 3, mineral fiber lay in ceiling

130 Sound Path Estimation D C SOUND POWER L w C =Casing Radiated and Induction Inlet O D O =Discharge Sound =Outlet Generated Sound

131 AHRI 880 Performance Rating of Air Terminals How to present catalog data tested in accordance with ASHRAE 130 Pressure drop Air capacity Radiated sound power Discharge sound power Power consumption Provides rating points for the Directory of Certified Performance

132 Performance Rating Terminal unit performance rated per AHRI Standard 880 Now includes new end reflection loss (ERL) correction that must be applied to discharge sound levels

133 What is end reflection? Occurs when sound source is ducted to room Noise reflected back to source Not captured in reverb room testing Deducted when estimating NC (??????) Can be calculated based on duct dimensions Sound Source ERL Room

134 Typical NC Levels Conference Rooms < NC30 Private offices < NC35 Open offices = NC40 Hallways, utility rooms, rest rooms < NC45 NC should match purpose of room Difficult to achieve less than NC30 Select diffusers for NC20 25 (or less)

135 Attenuators Single duct Equivalent to lined ductwork Dual duct Provides temperature mixing, but little sound attenuation Fan powered Lined elbow or boot may provide 2dB attenuation by removing line of sight to motor Carefully engineered attenuators can provide additional sound reductions

136 Silencers Must be tested with terminal unit Don t assume that silencer will provide published sound reduction A silencer could actually increase noise! Silencers are tested to a different standard Silencers work when applied as intended They perform differently when close coupled

137 Liners Softer and thicker liners tend to absorb sound Lower discharge sound Harder or more dense liners tend to block or reflect sound Lower radiated sound Higher discharge sound Lining effects on fanpowered products can be hard to predict

138 Performance certification AHRI maintains Directory of Certified Product Performance Voluntary program Manufacturers submit performance at the certified rating point Annual random samples are tested independently Failures result in mandatory re rating and additional testing This program keeps manufacturers honest But shouldn t be used to compare most products Rating points are not always best operating points

139 Safety agency listing National Electrical Code (NEC) requires UL or ETL listings on all electrical appliances UL Standard 1995 covers fan powered HVAC equipment Fan powered terminal units UL Standard 1996 covers non fan electric duct heaters Single duct terminals with electric heat UL Standard 429 covers electricallycontrolled valves Single and dual duct boxes with electronic controls

140 Safety agency listing Terminal unit products are typically ETL listed Less costly and more flexible than working with UL Faster turnaround for custom designs A safety agency listing covers Designed in accordance with all applicable UL safety standards Manufactured using all approved electrical components and assembly methods Manufactured in a controlled factory environment subject to random audit by agency Safety tested using approved methods and equipment prior to shipping

141 Safety agency listing Things you can do at the jobsite that won t void the safety listing Connect approved supply circuit Install low voltage controls Change out defective parts with properly rated replacement parts Make minor wiring changes that don t affect electrical ratings

142 Safety agency listing Things you shouldn t do that will void the safety listing Connect a supply circuit that doesn t match label requirements Install unapproved high voltage electrical parts inside the unit Change motor/heater voltage, motor HP, or heater KW Make wiring changes that affect the electrical characteristics

143 Terminal Units Features and Options Randy Zimmerman Chief Engineer

144 Inlet sensors Pitot tube Linear Annubar Modified Annubar Cross type

145 Pitot tube Single point sensor Measures true velocity pressure (no amplification) Total pressure port (front), TP Static pressure ports (side), SP Velocity pressure, VP = TP SP K fpm = 4005 Velocity (fpm) = K x VP 0.5

146 Linear annubar Multi point sensor, linear Measures amplified velocity pressure Total pressure ports (front), TP Depressed static pressure ports (rear), SP Amplified velocity pressure, VP = TP SP K fpm = 2650 Velocity (fpm) = K x VP 0.5

147 Modified annubar Multi point sensor, shaped Measures amplified velocity pressure Total pressure ports (front), TP Depressed static pressure ports (rear), SP Amplified velocity pressure, VP = TP SP K fpm = 2650 Velocity (fpm) = K x VP 0.5

148 Cross type Multi point, center averaging sensor Measures amplified velocity pressure Total pressure ports (front), TP Depressed static pressure ports (rear), SP Amplified velocity pressure, VP = TP SP K fpm = 2500 Velocity (fpm) = K x VP 0.5

149 Dampers Round dampers Low leakage One moving part Less chance of failure Opposed blade dampers Leakage at side and blade seals Spot welded linkages Worn pivot points

150 Liners Traditional liners Soft fiberglass Rigid fiberglass Solid dual wall Perforated dual wall Innovative liners Engineered polymer foam Natural fiber

151 Traditional liners Soft fiberglass Called dual density or matte faced fiberglass 0.5 or 1.0 thick R value = 1.9 or 3.9 Rigid fiberglass Called ductboard with scrim reinforced foil face Installed with galvanized Z brackets 1.0 thick R value = 4.3

152 Traditional liners Solid dual wall 22g galvanized steel over 1.0 thick fiberglass R value = 3.9 Perforated dual wall 22g perforated galvanized steel over 1.0 thick soft or rigid fiberglass R value = 3.9 Very costly, creates uncleanable surface

153 Innovative liners Engineered polymer foam insulation Called EPFI 0.5 or 1.0 thick R value = 2.0 or 4.0 Cannot absorb moisture Has anti microbial agent throughout Must be mechanically fastened

154 Innovative liners Natural fiber Recycled cotton or denim Matte faced or foil faced 0.5 or 1.0 thick R value = 2.0 or 4.0 Flame retardant Has anti microbial agent throughout

155 Liner standards Numerous standards out there ASTM C1071 Std Spec for Fibrous Glass Duct Lining Insulation ASTM C1104 Std Test Method for Determining the Water Vapor Sorption of Unfaced Mineral Fiber Insulation ASTM C1338 Std Test Method for Determining the Fungi Resistance of Insulation Materials and Facings ASTM E84 Std Test Method for Surface Burning Characteristics of Building Materials NFPA 90A Std for the Installation of Air Conditioning and Ventilating Systems NFPA 90B Std for the Installation of Warm Air Heating and Air Conditioning Systems

156 Liner standards Lots of confusion because Some standards are material specific Some standards are only method of test Some standards are referenced in other standards UL 181 Standard for Factory Made Air Ducts and Air Connectors Covers everything that manufacturers can use References all appropriate test methods All materials intended for use as duct or equipment lining must meet this standard

157 LEED and Liners Exposed lining materials must comply with UL 181 with regard to resistance to air erosion and mold growth LEED requires the air distribution system to comply with ASHRAE 62.1 Per ASHRAE 62.1, exposed lining materials must meet UL 181 with regard to resistance to air erosion and mold growth Every duct lining material should meet UL 181

158 LEED and Liners Is meeting LEED requirements all we care about? Just because you can put exposed fiberglass into a LEED Platinum building doesn t mean you should Liners such as engineered polymer foam and recycled natural fiber should provide improved indoor air quality with little if any added cost

159 Electric coils Staged 1, 2, or 3 stages Magnetic contactors for each stage Equal stages SCR Heater control board Solid state relays (SSR s) Elements arranged as a 1 stage heater Pulsed on/off Safety devices Airflow switch (ΔP = 0.05 in wg) 115 F auto reset thermal cutouts (per element) 160 F manual reset thermal cutout (per heater)

160 Hot water coils Typical construction 22g galvanized, uninsulated casing rippled aluminum fins 10 fins per inch (FPI) spacing 0.5 OD copper circuit tubes with tube wall 1 row and 2 row coils are crossflow circuited 3 row and 4 row coils are counterflowcircuited Leak tested to 450 psi Performance rated per AHRI Standard F maximum water temperature 360 psi maximum working pressure 1800 psi bursting pressure

161 Hot water coils Options Stainless steel, uninsulated casing Insulated covers Copper fins 12 fins per inch (FPI) spacing Circuit tubes with tube wall 500 psi/2500 psi Circuit tubes with tube wall 850 psi/4250 psi NPT fittings Vents and drains

162 Water coil problems Water connection Water coils should always be supplied at the lowest connection Prevents air from being trapped in coil circuits Low water flow Should be at least in the top half of transitional flow Coefficient of heat transfer is reduced in the lower half Minimum gpm is based on Reynolds number Affected by altitude, temperature, glycol, etc Poorly supported supply lines and water hammering Can result in stress fractures on header connections

163 Controls Pneumatic Electric Analog electronic Digital electronic

164 Pneumatic Found in existing buildings Pressure dependent Thermostat and damper actuator No controller No flow limit settings Pressure Independent Thermostat, controller, inlet sensor, damper actuator Piping and additional components can be complicated Powered by compressed air 20 psi Air system must be clean and dry Prevents contamination of controls

165 Electric Rarely used anymore Pressure dependent Thermostat and damper actuator No controller No flow limit settings Powered by low voltage 24 VAC

166 Analog electronic Found in small buildings or tenant spaces Pressure independent Thermostat, controller, inlet sensor, damper actuator Additional wiring, relays, and components can get complicated Powered by low voltage 24 VAC No communication capability, no networking

167 Digital electronic Found in most new construction Pressure independent Room sensor, controller/actuator, inlet sensor PID control algorithms Powered by low voltage 24 VAC Networked with BMS/BAS Communication protocol BACnet Echelon (Lonmark) Proprietary

168 Fan motors Permanent split capacitor (PSC) motors Sleeve bearings Speed range: rpm Efficiency: 20 60% Service life: years Electronically commutated motors (ECMs) Ball bearings AC/DC rectifier Programmable Speed range: rpm Efficiency 70 80% Service life: years

169 Speed controls PSC motors use SCR speed controls Silicon controlled rectifier (i.e. dimmer switch) Chops and distorts ac sinewave power Good for trimming, not chopping speed ECMs use PWM speed controls Pulse width modulated signal 0 20 VDC pulses to control module Manual adjust models available Remote control models available Accepts 0 10 VDC speed control signal Allows dynamic fan sequencing

170 Optional filters Optional filters are inexpensive disposable type Intended to be fitted during construction only Adequate to prevent dust contamination of motor and blower Most terminal units are operated without filters Hot water coils do not collect dust like condensing coils Accessibility of terminal units is a problem Terminal units should require zero maintenance Performance data never includes filters

171 Optional filters If filtering of return is necessary or desired Use filter grilles in the ceiling Provides easy access Allows for larger filters in less costly standard sizes

172 MERV rated filters MERV rated filters are available Most terminal units were never designed to use MERV rated filters Will likely reduce the maximum fan capacity Could create problems Sometimes design changes necessary Angled filter racks can enlarge filter area

173 Low profile Low profile terminal units were originally developed for the Washington, DC market High real estate cost Building height restrictions 12 ceiling plenums Product can be no more than 10.5 tall Low profile results in Lower airflow capacities Higher pressure drops Higher sound levels Also used in retrofit applications where space is tight

174 Low temperature Some systems are designed to operate with low temp air Typically use ice storage Supply temperatures as low as 38 F Lower air volumes and smaller ductwork Special terminal units Heavier liners for higher R value Thermally isolated inlet collars Standard single duct VAV boxes with 0.5 lining can handle 40 F supply air 80 F plenum air 60% RH

175 Low temperature Recommendations for low temperature buildings Order terminal units with 1.0 thick liners (R value = ) Use a ceiling plenum return Protects ductwork from stagnant air Do a soft start and gradually drop the supply temperature Allows the building to dry out Design the building to operate under positive pressure Prevents outdoor air infiltration Low temperature buildings are typically dry by nature, so condensation is not a major problem

176 Underfloor Underfloor terminals are usually fan powered units designed to boost airflow to spaces in UFAD systems Must fit between floor pedestals Must be serviceable from above Should be designed for zero maintenance

177 Terminal Units Selection and Sizing Randy Zimmerman Chief Engineer

178 Inlet selection Inlets should be selected carefully for Low noise levels Low pressure drop Accurate flow control VAV inlets should be selected for Maximum inlet velocity as close to 2000 fpm as possible Allows an 85% turndown with no loss of control accuracy CAV inlets allow much more flexibility Maximum inlet range of fpm

179 Operating pressures Inlet static pressure Most VAV systems operate at in wg Systems with series fan powered could be as low as 0.5 in wg Downstream static pressure Ductwork, take offs, balancing dampers, flex duct, and diffusers Most selections assume 0.25 in wg Minimum pressure requirement Min ΔPs across box with damper wide open including any coils Inlet SP >Min ΔPs + Downstream SP

180 Fan selection PSC Fan Curve ECM Fan Curve

181 Fan selection Fan selection depends on the type of motor Most selections are made with 0.25 in wg downstream Actual conditions are often 0.10 in wg or less Selecting PSC units near the minimum curve could easily put the fan outside its recommended operating range Selected Actual

182 Fan selection PSC fan motors should be selected in the top 25% of range Allows motor to run cooler and more efficiently Oversized motors running at low speed create rumbly noise

183 Fan selection ECMs should be selected in the lower 50% of range Oddly enough they run more quietly and efficiently at low speed

184 Electric coil selection Terminal units are generally limited to a current draw of 48A UL 1995 and 1996 require subdivided circuitry and additional fusing to exceed 48A Voltages and phases must increase as KW s increase Fan motor current must also be included Power frequency (Hz) does not affect electric coils Only affects inductive loads, not resistive loads Limit discharge temperature UL Maximum discharge temperature = 120 F ASHRAE Overhead heating < 15 F above desired room temperature Don t exceed 100 F to prevent intermittent operation and overheating of elements

185 Electric coil selection Be careful with small KW requirements Element wire gets smaller as KW gets smaller and voltage/phase increases Small heaters should Be lowest voltage, single phase, and single stage (or SCR) Staged heat on/off How many stages? SCR heat modulating Input signal? Discharge air temperature sensor?

186 Heat vs. reheat Sensible heating MBH = 1.08 x cfm x (LAT EAT)/1000 Heating is more efficient than reheating Supply air must be brought up to room temperature before heating can begin Desired room temp = 72 F Supply air = 55 F Heating design airflow = 800 cfm MBH (reheat) = 1.08 x 800 x (72 55)/1000 = 14.6 LAT should not exceed 90 F for good thermal comfort MBH (heating) = 1.08 x 800 x (90 72)/1000 = 15.6 In this example it takes 30.2 MBH at the coil to provide 15.6 MBH to the room

187 Heat vs. reheat Fan powered terminals Pull warm return air from ceiling return plenums or filter grilles Return air is warmer than room air Free heat (minus fan energy) Can switch on independently (no AHU) to maintain night setback temperatures

188 Hot water coil selection Too much information Entering water Entering air Leaving water Leaving air Capacity Airflow Water flow Air pressure drop Water pressure drop Really need to know Entering water Entering air Airflow Capacity or Leaving air Water flow Max Air pressure drop Max Water pressure drop Max Leaving water Min

189 Hot water coil selection Hot water coil selection shouldn t be that hard Select a coil that meets or exceeds the desired capacity or leaving air temp with exceeding the maximum water flow How many rows should I select? Coils are generally available in 1, 2, 3, or 4 rows Everyone avoids 3 row and 4 row coils Select a 1 row or 2 row coil If the selection software says your water flow is too low You need to reduce the coil rows If you are already selecting a 1 row coil, you didn t really want much heat anyway Don t forget about 12 FPI coils

190 Terminal Units Installation Randy Zimmerman Chief Engineer

191 Hanging terminal units Optional OEM hanger brackets Typically have 0.50 round or slotted hole Intended for use with hanger rods Hanger straps Strips of galvanized steel Run down the sides of unit, fastened with screws Trapeze hanger Angled or square tubular steel Used with hanger rods Run under units Not ideal can limit accessibility

192 Hanging terminal units What about spring isolation hangers? Not required to achieve catalog performance All hanging methods must meet local code requirements Can provide extra protection from vibration (especially on fan powered units)

193 Can I hang a box upside down? That depends Single duct without coil = YES, no problem Single duct with hot water coil = YES, supply to lowest connection Single duct with electric coil = YES, labels with be upside down Exhaust terminals = YES, no problem Dual duct = YES, no problem Series fan powered = YES, but access doors may be on top only Parallel fan powered = YES, but backdraft damper may require modification and access doors may be on top only. Retrofit terminals = YES, no problem

194 Can I turn a box on its side? That depends Single duct without coil = YES, no problem Single duct with hot water coil = NO, coil circuits will trap air Single duct with electric coil = YES, airflow switch must be moved Exhaust terminals = YES, no problem Dual duct = YES, no problem Series fan powered = YES, no problem unless it has a water coil Parallel fan powered = NO, backdraft damper won t close Retrofit terminals = YES, no problem

195 Can a box discharge up/down? That depends Single duct without coil = YES, no problem Single duct with hot water coil = NO, coil circuits will trap air Single duct with electric coil = YES, no problem Exhaust terminals = YES, no problem Dual duct = YES, no problem Series fan powered = YES, no problem unless it has a water coil Parallel fan powered = NO, backdraft damper won t close Retrofit terminals = YES, no problem

196 Picture time

197 Picture time

198 Electrical installation Supply circuit at a minimum must meet current NEC requirements Wire type and gauge Circuit breaker type and size Local code may have additional requirements for safety Must follow electrical data label on all installed equipment

199 Electrical ratings Motor full load amps (FLA) Motor nameplate or as tested Heater full load amps (FLA) Single phase, i= w/v Three phase, i= w/(v x 1.73) Unit full load amps (FLA) Unit (FLA) = motor #1 (FLA) + motor #2 (FLA) + heater (FLA) Minimum circuit ampacity (MCA) MCA = 1.25 x [motor #1 (FLA) + motor #2 (FLA) + heater (FLA)] Maximum overcurrent protection (MOP) MOP = 2.25 x motor #1 (FLA) + [motor #2 (FLA) + heater (FLA)]

200 Electrical ratings Minimum circuit ampacity (MCA) Defines minimum supply circuit size All supply circuit component ratings >MCA Maximum overcurrent protection (MOP) Prevents oversized circuit breakers MOP >MCA MOP > 15A Standard circuit breaker sizes 15, 20, 25, 30, 35, 40, 45, 50, 60A 15A rarely used in commercial construction 15A MOP units can be supplied with 20A breakers Breakers can go up one size so long as < 600A

201 Electrical ratings Optional fuses and fused disconnect switches Do not affect unit electrical ratings Same calculations as units without May or may not meet local disconnect switch requirements Supply circuit overcurrent protection is always external Connection lugs will not accommodate oversized wire

202 Electrical ratings Three phase power 3 wire or 4 wire? 4 wire is the current standard 3 wire found in older cities, some rural areas, and automobile assembly plants (?) 3 wire = L1, L2, L3 (three hot legs) 4 wire = L1, L2, L3, N (three hot legs and neutral) Neutral is an unbroken ground path to the breaker panel Delta = 208V or 480V, 3 wire Wye = 480V, 3 wire or 4 wire

203 Inlet conditions SMACNA recommends a minimum of 3 4 equivalent duct diameters of straight approach Not always possible Cross type sensors can reduce inaccuracy Bulkhead transitions are better than tapered transitions

204 Discharge ductwork Discharge ductwork isn t a critical concern No more than 1000 fpm Best to have some straight duct before an elbow Don t put flex duct directly on unit discharge Best to have at least 4 of lined duct before the first diffuser takeoff, especially on fan powered units

205

206 Questions?

207 Displacement Ventilation David Pich P.E. LEED AP Director of HVAC Technology Copyright Titus 2016 All rights reserved

208 Displacement Ventilation Systems Comfort & Contaminates Basic Concepts & System Benefits Outlet Types and Air Patterns Example Space Layouts Displacement & LEED Copyright Titus 2016 All rights reserved

209 ASHRAE Handbook 2015 Application Ch. 57 Fully Stratified Fully Mixed Displacement G.R.D. Copyright Titus 2016 All rights reserved

210 Thermal Comfort ASHRAE Standard 55 Thermal Environmental Conditions for Human Occupancy Maximum t Ankle to Neck = 5.4 F (3.0 ) Avoid drafts by keeping t se < 36 F (18 C) Copyright Titus 2016 All rights reserved

211 Fully Mixed Air Distribution Cooling Supply Air F ( C); Heating F ( C) High Velocity Supply Outside Occupied Zone Minimizes Temp. Variations in Space Uniform Contaminate Concentration Copyright Titus 2016 All rights reserved

212 Fully Mixed Air Distribution Mixed Air Distribution Mixed Contaminates Copyright Titus 2016 All rights reserved

213 Fully Stratified Air Distribution Cool Air Supply Only 60 F 68 F (16 C 20 C ) Air is Supplied Horizontally across the Floor at Low Velocity < 70 fpm (0.36 m/s) Temperature Stratification from Floor to Ceiling (Return) Contaminate Concentration reduced in Occupied Zone Copyright Titus 2016 All rights reserved

214 Fully Stratified Air Distribution Fully Stratified Air Distribution Fully Stratified Contaminates Copyright Titus 2016 All rights reserved

215 Copyright Titus 2016 All rights reserved Adjacent Zone

216 Displacement Ventilation Basic Concepts & System Benefits Copyright Titus 2016 All rights reserved

217 Basic System Concepts Low Energy ( < 0.04 Ps) (10Pa) Air Change Effectiveness (Std. 62.1, Ez = 1.2) Quiet Operation (< 25 NC) Copyright Titus 2016 All rights reserved

218 Displacement Cooling

219 Displacement Stratification

220 Low Energy Higher Equipment Efficiency Uses warmer supply air 65 F (18 C) compared with 55 F (13 C) Energy consumption is often reduced by raising discharge temperatures Extended Economizer Cycle Copyright Titus 2016 All rights reserved

221 HVAC System Benefits Heat sources outside the stratification layer are not considered in airflow calculations Lighting load is designed as equipment load, but not as space load Effects cooling load capacity, but not air distribution capacity Copyright Titus 2016 All rights reserved

222 Low Energy Lower horsepower fans 0.04 in. pressure (10 Pa) is required for proper diffuser performance Results in lower horsepower fans required = Fan Energy Savings Copyright Titus 2016 All rights reserved

223 Improved Ventilation ASHRAE Standard 62.1 Ventilation for Acceptable Indoor Air Quality Zone Air Distribution Effectiveness, E z Overhead Cooling System = 1.0 Displacement Ventilation = % Less Fresh Air Required Copyright Titus 2016 All rights reserved

224 Return Air Outlet located at ceiling level Allows heat from ceiling lights to be returned before it is able to mix with occupied zone Reduced supply volume means higher return temperatures Copyright Titus 2016 All rights reserved

225 Humidity A potential problem with warmer supply air temperatures is higher humidity Supply system must reduce relative humidity to less than 60% to meet IAQ concerns Condenser water reheat, run around coils, or face & bypass Use of a separate system to dry outside air or the use of desiccant dehumidification If 55 o F (13 o C) supply air is used for dehumidification, return air can be mixed with supply air to achieve 65 o F (18 o C) air Copyright Titus 2016 All rights reserved

226 Temperature Gradient Ceiling Height 9 (2.75m) 14 (4.25m) 50% Rule is applied 62 F 72 F 82 F 10 F 10 F REHVA Guide Copyright Titus 2016 All rights reserved

227 Temperature Gradient Ceiling Height > 14 (4.25m) 33% Rule 64 F 72 F 86 F, 8 F 14 F REHVA Guide (Displacement ventilation, REHVA) Copyright Titus 2016 All rights reserved

228 Application Examples Good applications Room height > 9.0 ft (2.75m) Open Plan Offices Meeting Rooms Casinos Restaurants Theaters, & Auditoriums Schools & Universities Copyright Titus 2016 All rights reserved

229 Application Examples Best Applications = Big Spaces Room height > 9.0 ft Open Plan Offices Atriums and Lobbies Restaurants and Casinos Theaters and Auditoriums Classrooms and Meeting Rooms Airports and Train Stations Museums and Public Spaces Copyright Titus 2016 All rights reserved

230 Displacement Ventilation Advantages Smaller cooling power for desired room temperature in the occupied area Improved air quality in occupied area Longer periods of free cooling Copyright Titus 2016 All rights reserved

231 Application Examples Poor Applications Room height < 9 ft Surplus heat is the main problem not air quality Contaminants are heavier than air (chloramine) In combination with mixing systems Copyright Titus 2016 All rights reserved

232 Displacement Ventilation Disadvantages Risk of draft due to placement of the diffusers Wall mounted devices often occupy large wall areas Stratified air becomes uncomfortable when cooling load exceeds ~30 Btu/hr/ft 2 (0.095/kW/m 2 ) Cannot heat with displacement ventilation Copyright Titus 2016 All rights reserved

233 Perimeter Heating Perimeter heating can not be accomplished with traditional displacement ventilation Separate system required in most applications: UFAD perimeter system Perimeter fan powered systems Ducting of hot or reheated air Baseboard Radiation Radiant panels Dual Chamber Diffuser Copyright Titus 2016 All rights reserved

234 Dual Chamber Diffuser Dual chamber plenum Displacement cooling Mixed-air heating Actuated diverter (24V) Displacement diffuser cooling Linear diffuser heating Copyright Titus 2016 All rights reserved

235 Low Level Mixed Heating

236 Applications Classroom The Willard School Near Boston, MA Built in accordance with California K12 specifications. Each class room has 2 DV units, +/ 3 Fthermostat and CO2 sensor Dedicated OAH, Radiant Ceiling (68) DVIR Units W 60 x H 24 Copyright Titus 2016 All rights reserved

237 DV Heating and Cooling Mode hvac.com Heating Mode Cooling Mode 31

238 Typical Classroom Zone Perimeter Zone Heating Internal Zone High Concentration of CO2 20 CFM per Student Mixing System 12.5 CFM per Student DV System Sensible and Latent Cooling Load Copyright Titus 2016 All rights reserved

239 Design Principles Induction Nozzles CB Stratified Air Discharge DV Integral Heat Transfer Coils Copyright Titus 2016 All rights reserved

240 Copyright Titus 2016 All rights reserved TAO Section View

241 Cooling mode operation Return Air 100% Exhausted Supply Airflow (70 to 71 ºF) Primary Airflow (55 to 58ºF) Room Air (75ºF) Chilled Water Supply Airflow (62 to 63ºF) Copyright Titus 2016 All rights reserved

242 Copyright Titus 2016 All rights reserved Video Cooling

243 Heating mode operation Exhausted Supply Airflow (85to 92ºF) Optional Heat Recovery Primary Airflow (62 to 66ºF) Room Air (70 to 72ºF) Supply Airflow (67 to 70ºF) Copyright Titus 2016 All rights reserved

244 Copyright Titus 2016 All rights reserved Heating Video

245 Copyright Titus 2016 All rights reserved Cooling Only

246 Combining with GEOTHERMAL APPLICATIONS Utilize the Ground Earth for Free sensible cooling. 45 to 55 Ground Temperature Copyright Titus 2016 All rights reserved 40

247 Copyright Titus 2016 All rights reserved 41

248 Patient Room w/ Displacement Single Bed Rooms Only ACH 6 total/2 outdoor Total ACH volume: floor to 6ft Stipulations for use Room exhaust Toilet transfer grille Copyright Titus 2016 All rights reserved

249 Patient Room w/ Displacement Copyright Titus 2016 All rights reserved

250 Displacement Ventilation Types of Outlets & Distribution Patterns Copyright Titus 2016 All rights reserved

251 Discharge Air Patterns Copyright Titus 2016 All rights reserved

252 Displacement Diffusers Standard adjacent zone from factory Modified adjacent zone after adjusting pattern controllers to change pattern Copyright Titus 2016 All rights reserved

253 Displacement Diffusers Rectangular Mounts in wall 1 way pattern Copyright Titus 2016 All rights reserved

254 Displacement Diffusers Rectangular Mounts in wall 1 way pattern Copyright Titus 2016 All rights reserved

255 Displacement Diffusers Rectangular Rectangular In wall, flush or floor mount Copyright Titus 2016 All rights reserved

256 Displacement Diffusers Rectangular 3 Way Rectangular Flush to wall or floor mount 3 way pattern Copyright Titus 2016 All rights reserved

257 Displacement Diffusers Rectangular Curved Face Flush or floor mount 3 way pattern Copyright Titus 2016 All rights reserved

258 Displacement Diffusers Rectangular Stair Riser Steps, Stair Risers applications Great for auditoriums, concert, arena s, and lecture halls Copyright Titus 2016 All rights reserved

259 Displacement Diffusers Circular Column or floor mount 360º discharge Copyright Titus 2016 All rights reserved

260 Displacement Diffusers Semi Circular 180º Sidewall or column applications 180º pattern Copyright Titus 2016 All rights reserved

261 Displacement Diffusers U shaped Semi circular w straight sides 3 way pattern Copyright Titus 2016 All rights reserved

262 Displacement Diffusers Corner/Flat Face Corner mount applications 2 way pattern Copyright Titus 2016 All rights reserved

263 Displacement Diffusers Corner w/ Curved Face Corner mount applications 2 way pattern Copyright Titus 2016 All rights reserved

264 Displacement Ventilation EXAMPLE Space Layouts Copyright Titus 2016 All rights reserved

265 Private Perimeter Office Perimeter Wall Copyright Titus 2016 All rights reserved

266 Open Plan Interior Office Copyright Titus 2016 All rights reserved

267 Interior Break Room 61 Round Outlets Copyright Titus 2016 All rights reserved

268 Perimeter Conference Room Outside Wall Copyright Titus 2016 All rights reserved

269 Elementary School Classroom Perimeter Wall Copyright Titus 2016 All rights reserved

270 ASHRAE Standards for LEED ASHRAE 62.1 IEQ Prerequisite 1: Minimum IAQ Performance IEQ Credit 1: Outdoor Air Delivery Monitoring IEQ Credit 2: Increased Ventilation IEQ Credit 6.2: Controllability of Systems: Thermal Comfort (for naturally ventilated spaces) ASHRAE Standard 55 IEQ Credit 6.2: Controllability of Systems: Thermal Comfort IEQ Credit 7.1: Thermal Comfort: Design IEQ Credit 7.2: Thermal Comfort: Verification Copyright Titus 2016 All rights reserved

271 Displacement Ventilation & LEED Minimum Energy Performance: EAp2 Optimize Energy Performance: EAc1 Minimum Indoor Air Quality Performance: IEQ p1 Increased Ventilation: IEQc2 Thermal Comfort Design: IEQc7.1 Copyright Titus 2016 All rights reserved

272 Publications HVAC Applications Handbook, Chapter 57 (ASHRAE, 2015) Fundamentals Handbook, Chapter 20 (ASHRAE, 2009) System Performance Evaluation and Guidelines for Displacement Ventilation (ASHRAE, 2003) Displacement Ventilation in Non Industrial Premises (REHVA, 2002) Copyright Titus 2016 All rights reserved

273 Questions? Copyright Titus 2016 All rights reserved

274 Underfloor Air Distribution David Pich P.E. LEED AP Director of HVAC Technology Copyright Titus 2017 All rights reserved

275 Raised access floors Originally used in computer rooms Widely used in open plan offices since 1995 House power voice and data cabling Benefits of RAF systems Easy access to cabling Eliminates power poles in space Simplifies service reconfiguration Issues with RAF systems Cost ($9 to $12/ft 2 cost add) Reduced floor to ceiling height Copyright Titus 2017 All rights reserved

276 Room air distribution Copyright Titus 2017 All rights reserved

277 Mixed air systems CFM = TSHG 1.08 x (T RETURN T SUPPLY ) Local temperature 75ºF CFM = TSHG 1.08 x (T RETURN T SUPPLY ) Elevation T ROOM T RETURN 75ºF Occupied Zone 75ºF Local Temperature Copyright Titus 2017 All rights reserved

278 Mixed air systems Per ASHRAE V EZ = 1.2 V EFF = C RETURN -C SUPPLY C ROOM -C SUPPLY 1 CFM = Local temperature TSHG 1.08 x (T RETURN T SUPPLY ) Elevation C ROOM C RETURN Occupied Zone Local CO 2 Concentration Copyright Titus 2017 All rights reserved

279 Room air distribution Totally Stratified Systems Fully Mixed Systems Displacement Ventilation Dilution Ventilation Overhead delivery 55 F supply air High entrainment Copyright Titus 2017 All rights reserved

280 Thermal displacement systems Displacement Conditioning Heat Source Copyright Titus 2017 All rights reserved

281 Thermal displacement systems 82ºF CFM = TSHG 1.08 x (T RETURN T SUPPLY ) 82ºF T FLOOR T ROOM T CEILING 64ºF 77ºF 73ºF 1.1 m Elevation 64ºF Occupied Zone 73ºF 77ºF Local temperature Copyright Titus 2017 All rights reserved

282 Thermal displacement systems Per ASHRAE V EZ = ºF V EZ = C RETURN -C SUPPLY C 1.1 -C SUPPLY C FLOOR C ROOM C CETURN 64ºF 77ºF 73ºF 1.1 m Elevation Occupied Zone CO 2 Concentration Copyright Titus 2017 All rights reserved

283 UFAD systems CFM = TSHG 1.08 x (T RETURN T SUPPLY ) Stagnant Zone T FLOOR T ROOM T CEILING 81ºF Stratified Zone T 50 Elevation 75ºF T 50 Mixed Zone Occupied Zone 63ºF Local temperature Copyright Titus 2017 All rights reserved

284 UFAD systems Per ASHRAE V EZ = 1.2 V EZ = C RETURN -C SUPPLY C 1.1 -C SUPPLY Stagnant Zone C FLOOR C ROOM C CETURN Stratified Zone T 50 Elevation T 50 Mixed Zone Occupied Zone CO 2 Concentration Copyright Titus 2017 All rights reserved

285 UFAD systems UFAD and displacement are not interchangeable terms Totally Stratified Systems Fully Mixed Systems Displacement Ventilation UFAD Systems Dilution Ventilation ASHRAE Standard (addendum a) awards a zone ventilation effectiveness of 1.2 to UFAD outlets whose throw to 50 FPM does not exceed 4.5 feet Copyright Titus 2017 All rights reserved

286 UFAD systems CFM = TSHG 1.08 x (T RETURN T SUPPLY ) T 50 Stagnant Zone Stratified Zone 77ºF T 50 Mixed Zone Elevation 75ºF Occupied Zone 63ºF Local temperature Copyright Titus 2017 All rights reserved

287 ASHRAE UFAD Design Tool 300 ft 2 interior zone, 12 Btu/h-ft 2 Requires 198 CFM (3 swirl diffusers) Requires 250 CFM (2 square diffusers) Additional 52 CFM (26% more) Copyright Titus 2017 All rights reserved

288 UFAD systems Per ASHRAE V EZ = 1.0 Stratified Zone C ROOM C RETURN T 50 T 50 Mixed Zone Elevation Occupied Zone Local CO 2 Concentration Copyright Titus 2017 All rights reserved

289 Drivers behind UFAD systems Compliment to RAF system Flexibility extends to HVAC services Economic justification Improved workplace environment Enhanced contaminant removal Individual thermal comfort control Sustainable technology Copyright Titus 2017 All rights reserved

290 Key advantages of UFAD systems Energy and operational advantages UFAD systems with low projection outlets allow heat from sources above the occupied zone to escape naturally UFAD systems extend the flexibility of the RAF platform to mechanical services Thermal comfort Thermal comfort is a state of mind, thermostats represent a statistical population UFAD outlets allow occupants to adjust airflow rates according to their individual preference! The placebo effect Health and productivity improvements Improved IEQ Increased productivity (2% increase = $10/ft 2 yr) Copyright Titus 2017 All rights reserved

291 UFAD system design Floor cavity as a supply air plenum Pressurization Heat transfer Outlet selection and performance Zone temperature control Plenum control strategies Copyright Titus 2017 All rights reserved

292 ASHRAE Underfloor Air Design Guide Contribution by industry experts Architects and consulting engineers Research institutions Owners representatives, including the GSA Equipment and raised floor manufacturers Building commissioning agents Specific guidance Room air distribution with UFAD systems Plenum design and construction (includes leakage prevention) Installation and commissioning System design and operation Code compliance and life safety Copyright Titus 2017 All rights reserved

293 Plenum thermal decay Supply air passing over the slab is heated by the return air below Design Guide suggests air temperature rises of up to 8 F in UFAD plenum Warmer perimeter area supply air temperatures result in lower ΔT thus require more supply air Copyright Titus 2017 All rights reserved

294 Temperature control and zoning Copyright Titus 2017 All rights reserved

295 Sensible cooling with passive beams Perimeter Zone Reduction of overall UFAD system airflow rate by 50% or more Copyright Titus 2017 All rights reserved

296 TAF R Access Floor Diffuser High induction air flow pattern Occupant adjustable damper Actuated version available Typical design point is cfm Throw between 4 5 ft. Low NC Standard and UL listed fire rated versions Copyright Titus 2017 All rights reserved

297 TAF R Access Floor Diffuser 1 diffuser per cubicle EQ Credit Point Individual comfort control Copyright Titus 2017 All rights reserved

298 TAF R Installation Spring clip compression fit Pre assembled Pressing directly into floor Copyright Titus 2017 All rights reserved

299 TAFR Actuated Option 24 VAC Electric Actuator RJ12 connections Plug and play installation Copyright Titus 2017 All rights reserved

300 TAF R Interconnect Diagram JCI TEC 3000 Series Controller Copyright Titus 2017 All rights reserved

301 Perimeter Heating Perimeter heating cannot be accomplished with the same system as the interior cooling system Separate system is required: Perimeter fan powered systems Ducting of hot or reheated air Hydronic systems Radiant panels Copyright Titus 2017 All rights reserved

302 Perimeter Loads UFAD systems are typically modular, but the function of handling perimeter loads isn t modular Do not want to break the stratification layer Create a diffuser plume that: Handles high thermal loads 225 cfm per 4' length at 0.07" w.c. Engages occupied zone, not stratified ceiling layer Saves cooling energy Avoids occupant complaints from air rolling back, dumping into interior space Copyright Titus 2017 All rights reserved

303 Typical Perimeter Installation Low horsepower fan powered terminal unit ducted to rectangular floor diffuser plenums Copyright Titus 2017 All rights reserved

304 TAF V, TAF D, TAF HC Plenums Rectangular diffuser and plenums for various applications TAF V VAV Plenum TAF D Plenum with inlet for ducting TAF HC heating/ cooling VAV plenum Copyright Titus 2017 All rights reserved

305 TAF V, TAF D, TAF HC Plenums Plenum sizes vary 8 x x x 12 Cores are available in multi piece 2 way or 4 way blow Copyright Titus 2017 All rights reserved

306 UFAD Fan Powered Terminals Modular designed to fit between floor pedestals Series fan powered terminal & Booster fan Available with ultra high efficiency ECM motors Helps contribute to LEED EA Credit 1 Optimize Energy Performance Hot water and electric reheat Using Lynergy Comfort Controls heater with optional discharge temperature sensor can help meet ASHRAE 62 recommendation for 15 o T Copyright Titus 2017 All rights reserved

307 LHK Series Fan Terminal Used in perimeter and conference rooms Any room with varying loads Primary supply air damper Supply pulls from the floor AeroCross TM flow sensor Option for two dampers Copyright Titus 2017 All rights reserved

308 PFC Booster Box Designed for use with ECM to modulate the fan based on perimeter temperature conditions 30% fan at 70 F and 100% at 75 F Can provide reduced airflow to allow for simultaneous cooling and heating per ASHRAE 90.1 Copyright Titus 2017 All rights reserved

309 Underfloor TAF L System Copyright Titus 2017 All rights reserved

310 TAF L V (Cooling Section) TAF L V Linear diffuser 4 length Variable linear bar diffuser 24V damper actuator Copyright Titus 2017 All rights reserved

311 Copyright Titus 2017 All rights reserved Transverse Transverse Apertures Apertures

312 Copyright Titus 2017 All rights reserved Transverse Apertures

313 Copyright Titus 2017 All rights reserved Transverse Apertures

314 Copyright Titus 2017 All rights reserved Transverse Apertures

315 Copyright Titus 2017 All rights reserved Transverse Apertures

316 Multi-deflection Bar Grille Transverse Apertures Copyright Titus 2017 All rights reserved

317 TAF L Demo Video Copyright Titus 2017 All rights reserved

318 TAF L W & TAF L E Fin tube perimeter heat system Self contained heating No simultaneous cooling and reheat Per ASHRAE BTUH per 4 ft. plenum Copyright Titus 2017 All rights reserved

319 TAF L W & TAF L E Copyright Titus 2017 All rights reserved

320 TAF L E SMOKE VIDEO Copyright Titus 2017 All rights reserved

321 UFAD Controls Interior Zones (CAV) Plenum pressure is maintained by adjusting fan capacity at the air handler Occupants can make minor changes which are viewed as setup adjustments and not operating adjustment Perimeter Zones (VAV) Typically experience perimeter load changes more than interior Automatic VAV control is preferred for perimeter zones Copyright Titus 2017 All rights reserved

322 Copyright Titus 2017 All rights reserved

323 TAF G Access Floor Diffuser Through the floor cabling Phone/data/power Grommet for small cabling Copyright Titus 2017 All rights reserved