1. Radiant 101 Casey Swanson & Him Ly

2. 29 June 2016©Uponor2 Terms and Definitions AUST- Average Uncontrolled Surface Temp. ― Area-weighted of all interior surfaces ― Excluding cooled panel MRT- Mean Radiant Temp. ― (AUST+cooled panel)/2 Operative Temp. ― Temp. an occupant feels ― (MRT + room temp)/2 ― Winter (68F – 75F) ― Summer (73F – 79F)

3. 29 June 2016©Uponor3 Calculating AUST-MRT-OT Room Temp. = 77F AUST = 78.2F MRT = 72.1F Operative Temp. = 74.6F Room Temp. = 68F AUST = 66.4F MRT = 75.7F Operative Temp. = 71.9F

4. 29 June 2016©Uponor4 National Building Code Requirements Refers to ASHRAE 55 on thermal comfort: “produce thermal environmental conditions acceptable to a majority /80% of the occupants within the space.” Factors: Metabolic rate / activity Clothing Air Temperature Air Speed Humidity Radiant Temperature

5. 29 June 2016©Uponor5 Thermal Comfort…ASHRAE Standard 55 Predicted  Percent Dissatisfied        F   F      Floor Surface  Temperature  F Design Range Ref. : ASHRAE Standard 55-2004

6. 29 June 2016©Uponor6 Thermal Comfort….ASHRAE Standard 55 Radiant Temperature Asymmetry, °F Predicted Percent Dissatisfied             Warm Ceiling Cool Ceiling Cool Wall Warm Wall Design Range Ref. : ASHRAE Standard 55-2004

7. 29 June 2016©Uponor7         Ref. : ASHRAE Standard 55-2004   Air Temperature Difference Between Head and Feet, °F        Predicted Percent Dissatisfied Design Range Thermal Comfort…ASHRAE Standard 55

8. 29 June 2016©Uponor8 Inconsistent temperatures Circulation of dust and allergens High (O&M) operating and maintenance costs Aesthetics Space considerations Building heights Large glazing areas Dry air Noise Window condensation Odor circulation Damp lower levels Common HVAC concerns that a radiant system can solve

9. 29 June 2016©Uponor9 Radiant Overview A hydronic system consists of an installation of embedded tubes or surface mounted panels Radiant heating and cooling systems use the structure and surfaces of an area to transfer energy ― In radiant heating systems, the energy moves away from the heated surface towards the cooler area ― In radiant cooling systems, the energy moves towards the cooled surface from the warmer area

10. 29 June 2016©Uponor10 T ih T oh RadiationConvection  oc T ic T sc & D p Ref. : ASHRAE Standard 55-2004 Convection

11. 29 June 2016©Uponor11 Radiant –Efficiencies  Water has roughly 3,500 times the energy transport capacity of air  With radiant space conditioning systems, the ventilation function is separate – The volume of air moved and component size can be up to 5 times less – Fan power and duct size is much smaller  The cost of a radiant system is comparable to traditional variable-air-volume (VAV) system *Analysis and statistics provided by the Lawrence Berkeley National Laboratory (LBNL)

12. 29 June 2016©Uponor12 Radiant System Economics LBNL modeled office buildings in 9 US cities comparing radiant with ventilation and all other forced air VAV systems  Findings: – Radiant cooling, on average, saves 30% overall energy for cooling and 27% on demand – Energy savings of 17% in cold, moist climates 42% in warmer, dry climates The Hearst Tower, New York City

13. System Types, Strategies and Design Considerations

14. 29 June 2016©Uponor14 There are two primary types of radiant systems ― High Mass: incorporates the mass of the building with tubing embedded within the structure ― Low Mass: uses surface mounted ceiling/wall panels Types of Systems

15. 29 June 2016©Uponor15 High Mass Systems (cooling) Draws the energy from the surface toward the embedded tubing in the slab or wall ― Chilled water is circulated through the tubing Similar installation to radiant floor heating systems ― Very common to incorporate a hybrid system that cools and heats based on demand ― Slower response times and more residual energy Low mass radiant cooling systems are based on the Fanger Concept ― They react fairly quickly to temperature change ― Have little or no residual energy ― Must be used as an active system Work well for retrofit applications Low Mass Systems

16. 29 June 2016©Uponor16 Types of Loads Sensible load ― Direct solar load Latent load ― Can not address ― Mechanical system is required The Akron Art Museum, Ohio

17. 29 June 2016©Uponor17 Sensible Load The external loads account for only 42% of the thermal cooling peak ― 28% of the internal gains were produced by lighting ― 13% by air transport ― 12% by people ― 5% by equipment This is the dry bulb heat or heat gain in the space Radiant cooled systems can handle a significant portion of this load Absorption is dependant upon a decreased surface temperature A typical office building in Los Angeles as modeled by LBNL

18. 29 June 2016©Uponor18 Latent Load This is the energy that is contained in the moisture in the air, the wet bulb load or gain A phase change is required to address this load Radiant cooling systems can not address this load ― The ventilation system must: ― Address the latent load ― Balance of the sensible load if any exists ― Control the level of humidity within the air system  Meet the requirements of the Indoor Air Quality Standards for fresh air Dew point is determined by the relative humidity and temperature within the space In most cases an Rh of 50% or lower will be sufficient to prevent condensation on the cooling surface Humidity level in the building must be controlled through the ventilation system

19. 29 June 2016©Uponor19 Direct Solar Load ` The Los Angels Federal Building, California Short wave radiation (sun, electrical lights) ― Energy transferred independent of room temperature and surrounding surfaces Amount of energy absorbed depends on absorbtivity of material In spaces with high solar gain 25 – 32 Btu/h/ft 2 If Solar load exceeds cooling capacity ― Increases the floor surface temperature ― Emits long wave radiation back into space

20. 29 June 2016©Uponor20 Direct Solar Load SurfacesAbsorptance  for Solar Radiation Carpet dark­­­­­______ Black metallic surfaces (asphalt, carbon, slate, paper..)0.85 -.98 Tile or plaster, white or light cream0.30 ─ 0.50 Red tile, stone or concrete, dark paints (red, brown, green, etc.)0.65 ─ 0.80 White painted surfaces0.23 ─ 0.49 Table: Absorptances for Solar Radiation, Source ASHRAE Fundamentals, 1996

21. 29 June 2016©Uponor21 Total Heat Exchange Coefficient ModeHeatingCooling SurfaceBtu/h · ft 2 · °FW/m 2 · º KBtu/h · ft 2 · °FW/m 2 · º K Floor1.9111.27 Wall1.48 8 Ceiling1.271.911

22. 29 June 2016©Uponor22 q(tot) = q(con) + ql,(rad) + qs,(rad) q(tot) = h(tot) x (to – ts) + qs,(rad) h(tot) – heat exchange coefficient to – operative temperature ts – floor surface temperature q(tot) – total space heat flux (Btu/sq ft) q(con) – convective heat flux (Btu/sq ft) ql(rad) – long wave radiative heat flux (Btu/sq ft) qs(rad) – short wave radiative heat flux (Btu/sq ft)

23. 29 June 2016©Uponor23 Design Considerations Floor coverings- less thermal resistance the better ― Avoid carpet Slab thickness and tube depth ― Min. ¾” over top of tubing (by Code) Tube spacing (typ. 6” oc) 5/8” hePEX ― Longer loop length ― Low head loss Dew point ― Depends on humidity and temperature ― Condensation

24. 29 June 2016©Uponor24 Design Considerations Radiant energy to condition a space is only a few degrees different from the temperature of the conditioned space The supply water temperature to the floor needs to be 2 degrees above the dew point In highly humid areas ― Buildings need to be moderately well air-sealed ― Ventilation air would need some dehumidification Cross section of the cooling surface needs to be big enough to deliver the cooling at a small water temperature differential

25. 29 June 2016©Uponor25 Design Considerations Keep the total loop lengths within standard coil lengths of 300 or 1,000 feet ― Two or three loops per 1,000 foot coil ― One loop per 300 foot coil ― Work out a straight forward, standardized basis of design ― Keep things consistent and repeatable ― 5/8” hePEX™ plus tubing at 6 or 9 inches on center Always design for the best possible system performance Remember, radiant cooling enhances, it is not a stand alone system Allows the downsizing of HVAC equipment and ductwork Design differential temperatures ― 5 - 8 o F for cooling ― 10 - 20 o F for heating

26. 29 June 2016©Uponor26 System Strategies Active systems are systems that run during the occupied time ― They provide a nearly steady set-point ― Typically cost more to operate Passive systems also called activated core or activated concrete systems They operate most often during the unoccupied time ― Occupants may experience a slight drift in set point temperature across the day ― Take advantage of off-peak energy rates to lower operating costs

27. 29 June 2016©Uponor27 Common Design Results Most radiant cooling designs fall within the following parameters  12 to 14 Btu/h/ft 2 of sensible cooling  Up to 32 Btu/h/ft 2 of solar absorption  66 o F minimum floor surface temperature  76 o F to 78 o F room set point temperature  55 o F thru 58 o F supply fluid temperature The Water + Life Building, Southern California

28. 29 June 2016©Uponor28 Common Radiant Applications Museums Institutional, educational and recreational facilities High-rise hotels / offices Manufacturing & retail spaces Hospitals/health care and assisted living facilities Dormitories, barracks & prisons Churches Wineries Airports Residential The Copenhagen Opera House

29. Featured Project

30. 29 June 2016©Uponor30 Bangkok International Airport Outdoor Temperature at 77-95°F and year round high RH relative humidity The annual horizontal solar radiation total is more than 1,500 kWh/m²a, results in a solar radiation of 1,000 W/m² 45,708 m 2 (492,000 ft 2 ) radiant cooling Humidity is conditioned in the airport to 50-60% Ventilation is four air changes/hour

31. 29 June 2016©Uponor31 Bangkok International Airport Radiant Cooling Supply Water Temp is 13°C (55°F) Return Water Temperature of 19°C (66°F) Cooling capacity of 80 W/m² (25.5 btu/ft²) 40% of the total load Airport Load is handled by the radiant cooling Total cooling load energy savings = 30.5 %

32. 29 June 2016©Uponor32 Bangkok International Airport

33. 29 June 2016©Uponor33 Bangkok International Airport Temperature Distribution 21 o C (70 o F) 55 o C (131 o F)

34. 29 June 2016©Uponor34 Bangkok International Airport Comparison of cooling loads for the entire airport Original Concept Total Load: 275 GWH/a 739 kWh/m 2 a Optimized Concept Total Load: 191 GWH/a 513 kWh/m 2 a 44% DECREASE

35. 29 June 2016©Uponor35 Design Services Assist in radiant systems design ― Design Parameters ― Heating/cooling sensible loads ― Solar gain ― Space setpoint and relative humidity ― Construction details Radiant schedule CAD loop layout Bill of materials

36. Questions? Thank you