1. Hydronic Radiant Heating & Cooling Twa Panel Systems Inc. 1201 4th Street Nisku, AB Canada, T9E 7L3 (780)-955-8757 www.twapanels.ca

2. Hydronic Radiant Heat. & Cool.Agenda Radiant Panel Systems Background Radiant Panel System Design Air-Side Design Water-Side Design Capacity Thermal Comfort Benefits & Limitations Radiant Panel Products Applications 3. Radiant Panel Systems Background 4. Radiant Panel SystemsBackground Origins in Europe Introduced to North America Metal ceilings and radiant systems (1950s) Seeking more capacity (Convection) Chilled Sails (1990s) Passive beams (1990s) Seeking integration of ventilation system and more capacity Active beams (Forced Convection) (2000s) 5. Radiant Panel SystemsBackground High acceptance rate in Europe Historically high energy costs North American market increasing due largely to: Green initiatives Increasing energy costs Increased installed base (Familiarity & Successful projects) Lowering cost due to increasingly competitive market 6. Radiant Panel SystemsBackground Hydronic systems use water as theenergy transport medium Water has many times the thermalcapacitance as compared to air 7. Radiant Panel Systems BackgroundModes of Heat TransferConductionConvection Radiation 8. Radiant Panel Systems Background What is Radiation? Heat transfer through ElectromagneticWaves between surfaces The radiation is defined by the wavelength or frequency: Infrared / thermal radiation 0.8 100 m Solar radiation 0.3 3.0 m Light 0.4 0.7 m Only mode that can travel through avacuum Process for heating and cooling theEARTH 9. Radiant Panel SystemsBackground Radiant panel systems must be combined with aventilation system Displacement ventilation Traditional overhead air distribution Active beams Natural ventilation Operable windowsTerminology Decoupled VentilationTerminology Mixed-mode Ventilation 10. Radiant Panel System BasicsSystemsBackground Construction Steel or aluminum panel Aluminum extrusions Aluminum sheet metal Steel sheet metal Copper coil attached to panel Integrated saddle Mechanically attached saddle Conductive thermal paste Insulation Acoustic perforations Panels available in differentstyles and shapes 11. Radiant Panel System BasicsSystemsBackground How Heating Works Perimeter Radiant CeilingRadiant Ceilingnet heatnet heat = + +=transfertransfer+objects=net heat transfer 12. Radiant Panel System BasicsSystemsBackground How Cooling Works Radiant Ceiling net heatnet heat = + += transfertransfer +objects = net heat transfer 13. Air-side System Design 14. Radiant Panel System DesignAir-side Design Principles Overview Meet all ventilation requirements Min. Vent. (O/A requirements) Remove 100% of the latent loads (Psychrometrics) Maintain building static pressure Supplement sensible loads**Greatest of these factors sets the minimum air flow rate** Higher SAT may be used (Displacement Vent.) May use heat recovery strategies for increased energy savings Decreased AHU & Duct size Decrease in fan energy 15. Radiant Panel System DesignAir-side Design Principles Energy Savings Majority of energy is saved at the FAN Air-side Load Fraction (ALF) The smaller the air-side load fraction, the more energy can be saved by using a radiant system OfficeClassroomLobby O/A Requirement (cfm/ft2)0.15 0.5 1Air Volume (All Air System) 11.5 2(cfm/ft2)Air-side Load Fraction15%33% 50% Suitability engineering check - % of Sensible from CFMLatent 16. Radiant Panel System DesignAir-side Design Principles Energy Savings 17. Radiant Panel System Basics DesignAir-side Design Principles PsychrometricsPsychrometric review required to prevent condensationStandard Procedure: Remove moisture from the P/A at AHU Dry P/A lowers the space dew point temperature To prevent condensate on the coil:Space dew point temp. < EWT 18. Radiant Panel System DesignAir-side Design Principles PsychrometricsOption 1 Option 2Primary air dew point 48F51.5F Room air dew point 55F57.8FSecondary CWT55F 58F Dehumidification0.002 lbs/lbDA 0.002 lbs/lbDARESET FOR ENERGYSAVINGS! 19. Radiant Panel System DesignAir-side Design Principles Psychrometrics & Region Legend: Easy , Application of radiant products is natural Medium , Application of radiant products requires some additional design tocontrol building moisture Difficult, Application of radiant products is more difficult and humidity must becarefully considered 20. Radiant Panel System DesignAir-side Design Principles Design ParametersTypical Design Conditions (Cooling): S/A Space TDry Bulb:55 - 65 F TDry Bulb:75 F TWet Bulb:53 - 57 F TWet Bulb:64 F TDew point: 52 FTDew point: 58 F R.H.: 55%Gr = 13.64 Gr/lbTypical Design Conditions (Heating): S/A Space TDry Bulb:65 FTDry Bulb: 70 F R.H.:50% QL = 0.68*CFM*Gr Qs = 1.08*CFM*T 21. Radiant Panel System DesignAir-side Design Principles - Considerations Maintain reasonable dew point control Meet 100% of latent load under Peak Design conditions Infiltration Maximum occupancy Other sources of moisture Limit over-cooling Keep air-side load fraction low Reset air temperature CHWS Shut-off control or EWT reset VAV for fluctuating occupancy 22. Radiant Panel System Basics DesignAir-side Design Principles Control Sensors %RH sensor Condensation sensors Typically locate one on the supply water tubing in an area most likely to have the highest dew point Use a sensor to shut off valve or reset EWTSensor Location Advantages DisadvantagesOn the face of the beam / panel Humidity is measured where the Integration into the beam or panelrisk of room condensation is the may require increasedhighest. coordination. Sensor may be difficult to access for calibration.In the zone Humidity is measured at theLocal spikes in the humidity maysource of the moisture cause the system to be overlySensor is easily accessible. responsive, reducing capacity.In the return ductA more average reading of theCannot respond to local humidityzone humidity is taken,issues.maximizing the operation of thebeam. 23. Radiant Panel System DesignAir-side Design Principles Common Pitfalls Two Air-side Design Concerns: 1) Psychrometrics (Cooling only) 2) Preliminary Design based on DOAS system 24. Water-side System Design 25. Radiant Panel System DesignWater-Side Design Principles Overview Responsible for majority of the sensible loads Coil nom. Pipe with 180bends Design requires: Water flow rate Circuit pressure drop Temperatures (EWT, MWT, LWT) Increase in pump size and pump energy Fan Energy vs. Pump Energy = Net energy savings 26. Radiant Panel System DesignWater-Side Design Principles Design Parameters Radiant Cooling: EWT temperature, typically between 56 62F Secondary CHWS loop required T across panel, typically 4 - 6F Psychrometrics (Condensation control) Generally EWT = 2 3 F above SPACE dew point temp. Radiant Heating: EWT temperature, typically between 120 180F T across panel, typically 20 - 30F Minimum flow rate per circuit = 0.65 GPM Prevent laminar flow (more important for cooling) 27. Radiant Panel System BasicsDesign Water-Side Design Principles PipingWater system pressure control Variable speed pump anddifferential pressure sensor Reduces energy by loweringpump loading Can cause imbalances in thesystem when not at full flow ifpressure independent flowcontrol valves are not used 28. Radiant Panel System Basics DesignWater-Side Design Principles PipingDirect return Length of pipe varies from supplyheader to return header for eachunit Change in pressure drop fromone circuit to another, affects flowrates Use balancing valves or circuitsetters Can cause imbalances in thesystem when not at full flow ifpressure independent flowcontrol valves are not used 29. Radiant Panel System Basics DesignWater-Side Design Principles PipingReverse return First supplied, last returned Zone or array is self-balancing Number of balancing valves canbe reduced Additional pipe length required May require pressureindependent flow control valvesat mains for zone take off 30. Radiant Panel System Basics DesignWater-Side Design Principles PipingSeries piping Used to connect panels smallerzones Reduced piping, valving, andbalancing costs Higher flow rate to maintain T Too many panels in series leadsto reduced response and largetemperature difference between1st and last panels 200 total of coil piping is upperlimit for T and W.P.D. 31. Radiant Panel System Basics DesignWater-Side Design Principles PipingParallel piping Used with large panels andconnecting several sets of panelsin series Reduced pressure loss Lower flow rates to achieve T Better temperature distributionand response 32. Radiant Panel System DesignWater-Side Design Principles Future Advancements Integrated Reverse-Return Piping: 30 wide 6 pass panel 6 interconnectors per joint vs. 2 Uniform heat distribution 33. Radiant Panel System DesignWater-Side Design Principles Common Pitfalls Three water-side Design Concerns: 1) Use of Glycol as the operating fluid Especially in cooling 2) Not considering Pressure independent flow control valves Especially with large hydronic systems Modulating valves Variable frequency drive pumps 3) Valve & Entrapped air noise 34. 73F 60FRadiant Panel Capacity 35. Radiant Panel System Basics DesignHeating / Cooling Capacity Capacity is a function of: Emissivity of panel surface (= 0.9 0.98) Paint Color, finish, etc. Radiation (50-70%, Heating & Cooling) Stefan-Boltzmann Equation qr = 0.15x10-8 [(tpanel+460)4 (AUST+460)4] for = 0.9 Convection (20-50%, Cooling currents from panel surfaces) qc = 0.31 |tpanel- tair|0.31 (tpanel- tair) cooled ceiling surface Location of panel Proximity to warm / cool surfaces 36. Radiant Panel System BasicsSystemsCharacteristic Radiant Field Radiation Angle View factor (Line of sight) Effectiveness of radiant panels 37. Radiant Panel System Basics DesignHeating / Cooling Capacity Selection Tables: Cooling requireslarger area of panel 38. Radiant Panel System Basics DesignHeating / Cooling Capacity Typically active area is limited to