Hydronic radiant cooling systems have been used worldwide for decades. Now are gaining popularity also in North America and become an effective alternative to traditional all-air systems. New building codes and regulations demand for more energy efficient HVAC systems and radiant cooling is a proven an effective technology for cooling residential and commercial buildings. It is the preferred choice for designers to meet standards of Passive House, NetZero energy buildings, green and sustainable architecture. This presentation will address common questions and concerns and also analyze some of the benefits in terms of thermal comfort, wellbeing and productivity of occupants as well as substantial reduction of ductwork cross-sectional dimensions, operational and maintenance costs. Several case studies of radiant cooling projects will be presented.

1. Radiant Cooling for Commercial and
Residential Applications
Messana Radiant Cooling
radiantcooling.com
info@radiantcooling.com

2. MESSANA RADIANT COOLING - HISTORY
• 1991-1993 First experiments in radiant cooling (floor)
• 1994 Founded FCC srl (Floor Clima Control) – 21 years of growth and development
• 1991-1998 1,000 in-floor installations (radiant heating and cooling)
• 1997 First experiments of radiant cooling on the ceiling – Roberto Messana’s home
• 1998 First radiant ceiling drywall panel (Planterm, world wide patent)
• 2009 Developed Ray∙Magic (US patent)
• 2009 Founded MESSANA AIR-RAY CONDITIONING (European Headquarters)
• 2011 Founded MESSANA North America – Messana Radiant Cooling

3. TEN THOUSAND INSTALLATIONS (2016)
1st ceiling installation (1997)
• Europe
• North America
• Asia
• Africa
• 60% Commercial
• 40% Residential

4. PRODUCTION LINE AND THE LASER
2
min
1 panel every

5. Hydronic radiant cooling systems have been used worldwide for decades.
Now are gaining popularity also in North America and become an effective
alternative to traditional all-air systems. New building codes and regulations
demand for more energy efficient HVAC systems and radiant cooling is a
proven an effective technology for cooling residential and commercial
buildings. It is the preferred choice for designers to meet standards of
Passive House, NetZero energy buildings, green and sustainable
architecture. This presentation will address common questions and concerns
and also analyze some of the benefits in terms of thermal comfort,
wellbeing and productivity of occupants as well as substantial reduction of
ductwork cross-sectional dimensions, operational and maintenance costs.
Several case studies of radiant cooling projects will be presented.
SESSION DESCRIPTION

6. 1. Understand the basic physics principles of radiant cooling
technology and hydronic radiant ceiling systems.
2. Identify and describe the fundamental components of a radiant
cooling and heating system: hot and cold water source, radiant
delivery system, ventilation and dehumidification and controls.
Distinguish different types of radiant panels and understand the
advantages of radiant celling compared to traditional radiant
floor.
LEARNING OBJECTIVES

7. 3. Compare hydronic radiant cooling systems to traditional air-
based systems and analyze the key benefits with regard to
thermal wellbeing, productivity, energy efficiency, reduced duct
sizes and operational and maintenance costs.
4. Educate clients on considering a radiant cooling system for
their new building or renovation projects and discuss their
concerns about being an early adopter. Make preliminary
budget analysis.
LEARNING OBJECTIVES

8. Outline
1. What is “radiant cooling”?
2. Comfort in radiant systems
3. Advantages of Radiant Cooling vs traditional
air-based cooling system
4. Components of a Radiant cooling systems
5. Performance and cost of a radiant cooling
system
6. Examples of applications

9. 1.1 “Radiant cool” is not a physics phenomenon
“Radiant cooling systems are based on
absorption of thermal radiation”
Radiant heat is a form of energy..
what is “radiant cool”?
Scientifically speaking, does not exist.
“Radiant cool” is not a physics phenomenon,
and calling it “radiant cooling” is a pure
convention.

10. 1.2 What is radiant cooling?
It is a technology to buildings based on the sensible
through cold surfaces (radiant panels)

11. 1.3 Heat (Thermal energy)
Matter is made up of particles that
vibrate based on the temperature.
The hotter the substance, the more
its molecules vibrate, and
therefore the higher its thermal
energy.
particles of matter
By definition, heat is a form of energy that
flows from a point at one temperature to
another point at a lower temperature.

12. 1.4 Heat: vibration of particles
particles of matter
WARMER PARTICLES
vibrate faster, the space between particles
increases (less density and weight)
COOLER PARTICLES
vibrate less, taking up less space
(greater density and weight)

13. 1.5 Heat “goes up”?
“Heat goes up and cold goes down” is a common
belief about heat.
But it’s false!
All you need to do is stand in the sun to
understand.
The explanation lies in the confusion of terms.
While it’s incorrect to say “heat goes up”, it is
correct to say, “hot air rises”, which clarifies that
the concept of heat is a broader concept which
does not involve just the movement of air.

14. 1.6 Sensible and latent heat
sensible heat latent heat
There are two forms of heat:

15. 1.7 Sensible heat
Radiant heat is related ONLY to sensible heat
Sensible heat is an expression of the degree of
molecular excitation.
Is the one we usually have in mind when we
speak of heat.

16. 1.8 Latent heat
Related to the humidity
Heat that changes the state of matter from
solid to liquid or liquid to gas is called latent
heat.

17. 1.9 How does sensible heat transfer?

18. 1.10 Conduction
Conduction is the process whereby molecular
excitation spreads through a substance or from
one substance to another by direct contact.

19. 1.11 Conduction
The higher is the conductivity the better heat
transfers across materials.

20. 1.12 Conduction
Cold goes up Heat goes down

21. 1.13 Convection
Convection occurs in
fluids and is the
process of carrying
heat stored in a
particle of the fluid
to another location
where the heat can
conduct away.

22. 1.14 Hot air rises

23. 1.15 Forced vs Natural Convection

24. 1.16 Radiation
Heat in the form of Electromagnetic Waves
Stright line vabration
(thermal radiation)
All bodies emit thermal radiation
WavefrontRAY
Particel of
matter
671M mph
speed of light
Heat in the form of Matter
in the solid and fluid state
Circular motion vibration
(themal motion: convection
and conduction)

25. 1.17 Electromagnetic spectrum
Infrared spectrum
Any object that has a temperature above absolute zero (the point where atoms and
molecules cease to move) radiates in the infrared.
Also a cube of ice that we perceive as “cold”, radiates.

26. 1.18 Example of “visible” thermal radiation
Sunlight is part of thermal
radiation generated by the hot
plasma of the Sun
visible light and infrared light emitted by
an incandescent light bulb

27. 1.20 Radiation of radiant systems
Radiant heating and cooling system operate at temperature with emission in
the infrared, invisible to the human eye..
These types of radiation are not directly visible to the naked eye, but we
perceive their effect as a sensation of warmth or “coldth” through special
receptors in our skin.

28. Faster vibration
higher temp
Slower vibration
Lower temp
Warmer
particel
Electromagnetic
wave
speed of light
Cooler
particel
1.21 Thermal radiation (radiant cooling)

29. Faster vibration
Higher temp
Warmer
particel
Electromagnetic
wave
speed of light
1.22 Thermal radiation (radiant heating)
Slower vibration
Lower temp
Cooler
particel
Heatdoesgoesdown!

30. 2.1 Comfort
ears
eyes
nose
tactile
receptors
thermoreceptors and
(heat and cold sensors)
The feeling of comfort or, more accurately, discomfort
is based on a network of sense organs:

31. 2.2 Thermoreceptors
They are nerve endings in
the skin responsible for
sensitivity to vibration
Humans have at least two types of temperature
sensors (thermoreceptors):
• heat receptors (Ruffini endings)
• cold receptors (end-bulbs of Krause)

32. 2.3 Thermal comfort
Thermal comfort is that
state of mind that is
satisfied with the
environment
condition of minimal
stimulation of the skin’s
heat and cool sensors

33. 2.4 The factors of thermal comfort
• Dust
• Acoustics
• Aesthetics
• Odors
• Lighting
• Air temperature
• Radiant temperatures of
the surrounding surfaces
• Humidity of the air
• Air motion
For comfort and efficiency, the human body
requires a fairly narrow range of
environmental conditions:
Can be controlled by a radiant
ceiling system
Can be
partially
controlled by a
radiant ceiling
system
Not related

34. Cold sensors
Heat sensors
Pressure
sensors
SKIN
Localized thermal absorption
with possible physical
discomfort
Wasted electrochemical
energy
(Brain efficiency reduction)
2.5 Discomfort with forced air

35. Cold sensors
Heat sensors
Pressure
sensors
SKIN
2.6 Comfort in natural convection
Vibration
(heat)
Electrochemical
energy

36. 2.7 Heat balance
Cheeseburger
(Big Mac)
540 kcal
The human body is a complex machine that
“burns” food for energy and must discard the
excess heat.
food = chemical energy

37. 2.8 Heat exchange
Depending on the temperature of the
surrounding objects and ambient air the body
can either gain or lose heat by:
Radiation
Convection
Conduction
Evaporation (only heat loss)

38. Radiation
Evaporation
Convection
Conduction
2.9 Heat loss

39. 2.10 Evaporation
sweat
gland
hair
pore
osmotic
evaporation
sweat
Evaporation is exclusively a cooling mechanism.
It is dependent to a minor degree on the relative humidity of
the surrounding air and, to a much greater extent, on the
velocity of air motion.

40. 2.11 Osmotic evaporation
Water is naturally lost from the human body by
evaporation across the skin.. this is a natural form of
heat loos

41. 2.12 Sweating
Sweating is a mechanism of heat loss when the body can not naturally lose enough
heat (overheating). It is a sort of “self-defense mechanism” of the human body.
The opposite mechanism is shivering to increase heat production in the muscles,
when the body temperature is too low.

42. SUMMER WINTER
SUMMER WINTER
RADIATION 45-50% 30-35%
NATURAL CONVECTION 15-20% 20-30%
OSMOTIC EVAPORATION 35-40% 40-50%
2.13 Optimal proportion of thermal exchange
Thermal comfort is the right balance of thermal exchange between radiation,
convection and evaporation.
Comfort essence is proportion + uniformity

43. 3. Advantages of Radiant Cooling Systems
3.1 Thermal comfort/Thermal Wellbeing
3.2 Acoustical
3.3 Aesthetics
3.4 Zoning
3.5 Energy saving
3.6 Compact design and less ductwork
3.9 Humidity in the winter
3.7 Lower maintenance cost
3.8 No dust movement

44. 45-50%
MRT=68-74F
35-40%
DPT=55F
15-20%
DBT=72-78F
<1%
Radiation
Evaporation
Convection
Conduction
3.1.1 Thermal exchange in radiant cooling

45. 10-15%
MRT=80-86F
50-55%
DPT=45-50F
25-30%
DBT=70-76F
<1%
Conduction
3.1.2 Thermal exchange with air condictioning
Radiation
Evaporation
Convection

46. 3.1.3 Comfort (radiant ceiling)

47. 3.1.4 Comfort (radiant floor)

48. 3.1.5 Discomfort (fan-coil)

49. 3.1.6 Uniformity (radiant ceiling)

50. 3.1.7 Uniformity (radiant floor)

51. 3.1.8 Uniformity (fan-coil)

52. 3.1.9 Uniformity in office space

53. 3.2 Acoustical comfort

54. 3.3 Aesthetics
Radiant gypsum ceiling gives
architectural freedom
Convectors, grids and wall split
systems are waste space and the the
beautiful modern look of this space
radiant panels are embedded within
the ceiling and are invisible and waste
no space

55. 3.4.1 Zoning
1. 1¼" Supply manifold
2. 1¼" Return manifold
3. 1" Female NTP adapter
4. Automatic air vent valve
5. C/F Temperature gauge
6. Fill/Drain with safety plug
7. Quick connect probe
8. Balancing valve body
9. Balancing valve plastic cap
10. Snap-In Manifold 5/8" adapter
Pex-Al-Pex
11. Thermal Actuator
12. Installation bracket
13. Insulation
Spaces may be zoned by the use of a control
valve for each zone.

56. 3.4.2 Zoning
manifolds
Apartment A (14 zones) Apartment B (10 zones)

57. 3.5 Energy saving
Radiant cooling systems are projected to save
significant energy (42%) when compared with
air-based cooling systems.
Why a radiant cooling system save energy?

58. 3.5 Energy saving
Area
requirements
Water has roughly 3,500 times the energy
transport capacity of air. Hydronic system can
transport a given amount of cooling with less
than 5% of the energy required to deliver cool
air with fans

59. 3.5 Energy saving
Lawrence Berkeley National
Laboratory (LBNL) ran detailed
simulations of the same prototypical
office building located in nine U.S.
cities, comparing the performance
of radiant cooling systems with
ventilation and conventional “all-
air” VAV systems. In comparisons
with VAV systems, it was found that,
the radiant cooling systems save
30% on average on overall energy
for cooling. Energy saved ranges
from 17 % in cold, moist areas to
42% in warmer, dry areas.
Source: Lawrence Berkeley National Laboratory

60. 3.6 Compact design and less ductwork
shorter ceiling-floor assembly, higher
ceiling or more floors in high rise building
add about one floor for every five
floors
allow ceiling heights to be raised to an
architecturally pleasing level (>9ft)
ductwork cross-sectional dimensions
become much smaller

61. 3.8.1 Dust with RADIANT CEILING
• dust is not in touch with the hot
surface
• no air movement
• no dust movement
• dust is not in touch with the cold
surface
• cold air moves down
• no dust movement

62. 3.8.2 Dust with RADIANT WALL
• dust is not in touch with radiant
surface
• air movement (natural convection)
• dust movement on floor
• dust is not in touch with radiant
surface
• air movement (natural convection)
• dust movement on floor

63. 2.8.3 Dust with RADIANT FLOOR
• dust is in touch with radiant surface
• air movement (natural convection)
• dust is raised up from the floor
• dust is in touch with radiant surface
• no air movement
• no dust movement

64. 3.8.4 Dust with Fan-coil
• dust is not in touch with radiant
surface
• air is blown (forced air)
• dust is raised up from the floor and
blown
• dust is not in touch with radiant
surface
• air is blown (forced air)
• dust is raised up from the floor and
blown

65. 3.9 Humidity in the winter

66. 4. Messana radiant cooling system

67. 4. Heat Pump
In summer it
moves heat from
the inside to the
outside
• Ideal for radiant heating
and cooling system
• Very high energy efficiency
• Water to water system with
hydronic radiant ceiling
Air-to-water
Water-to-water (geothermal)

68. 4. Radiant cooling terminals
radiant floor
systems
radiant panels for ceiling and walls
(gypsum, MDF or metal)
• Energy (sensible heat) delivery system
• Radiant panels are heat terminal devices
• The radiant panel exchanges heat with the
indoor environment (air, walls, objects)

69. 4. Radiant ceiling vs floor
HEATING COOLING
floor ceiling floor ceiling
Performance
BTU/H/SQ.FT
40 60 10-15 35-40
Move Dust Yes No No No
Response time 30m / hours 1m / minutes 1h / hours 2m / minutes

70. 3.9 Ceiling vs Floor (air T response time)

71. 3.9 Ceiling vs Floor (surface T response time)

72. 4. Ray Magic Radiant ceiling gypsum panels
1. Pre-formed EPS substrate
2. Aluminum heat transfer plates
3. Three way snap-in fittings
4. 5/8” Pex-Al-Pex sliding
backbones
5. Two embedded hydronic
circuits
6. Gypsum board with
AirRenew™ technology
7. Tubing footprint laser
engraved (ink free)
8. 16”/24” O.C. fastening
template
9. Gypsum semicircle cut out

73. 4. Radiant ceiling gypsum panels
acoustic

74. 4. Climakustic, acoustical MDF radiant
panels

76. 4. Dew-point
The temperature at which
condensation begins is
known as the dew-point
temperature.
Condensation will occur if
the ceiling surface goes
below the dew-point.

77. 4. Control Magic Radiant Cooling Controls
The key component of the messana radiant
cooling system to avoid condensation, provide
comfort and optimize energy.
1. TTL Port
2. Analog Outputs
3. 2x USB Port
4. Analog Inputs
5. RS485 Port
6. Digital Inputs
7. WAN Port
8. Digital Outputs
9. LAN Ports
10. Power Input

78. 4. Control Magic System
latent sensible

79. 4. Air Magic Neutral Temperature
Dehumidifier
NTD is a device that reduces the level of
humidity in the air (latent heat).
IT IS NOT THE SOLUTION TO CONDENSATION!

80. 4. Dehumidification
1 SUPPLY OUTLET
2 SUPPLY BLOWER
3 AIR PRE-TREATMENT COIL
4 EVAPORATOR
5 COMPRESSOR
6 WATER SUPPLY
7 WATER RETURN
8 DRAIN
Neutral temperature dehumidifier

81. 4. Dehumidification and HRV
1 SUPPLY OUTLET
2 RETURN INLET
3 BATHROOM EXH OUTLET
4 EXHAUST OUTLET
5. FRESH AIR INLET
6 EXHAUST BLOWER
7 HEAT EXCHANGER
8 AIR FILTER
9 RECIRCULATION DAMPER
10 AIR PRE-TREATMENT COIL
11 SUPPLY BLOWER
12 ROTATIVE COMPRESSOR
Air Treatment Unit
Combination of neutral
temperature dehumidifier
and Heat Recovery
Ventilation unit

82. 4. Radiant ceiling panel performance
The radiant heat transfer is governed by the Stefan-Boltzmann
equation.
qr = 0.15 x 10–8 [(tp)4 – (AUST)4]
where
• qr = radiant cooling, Btu/h·ft2 (W/m2)
• tp = mean panel surface temperature, °R (K)
• AUST = area weighted average temperature of the non
radiant panel surfaces of the room, °R (K). Normally this
means that the air temperature (ta) is about this
temperature as well.

83. Convective Heat Transfer
The rate of heat transfer by convection is a combination
of natural and forced convection. Natural convection results
from the cooled air in the boundary layer just below the panels
being displaced by warmer air in the room.
Research suggests (Min 1956) that for practical panel cooling
applications without forced convection, the cooling convective
heat transfer is given by the following equation
qc = 0.31(tp – ta)0.31(tp – ta).

84. 6. Examples of applications

85. New single family home in New Canaan, Connecticut
RESIDENTIAL
Awarded “Best in Town Custom Home” and
“Best New Construction Technology”
in CT by HBRA of Connecticut, Inc

87. Palo Alto, CA
RESIDENTIAL
NetZero Passive house
PHIUS+ and LEED Platinum certifications

89. Ojai, CA
RESIDENTIAL
ROWLAND Residence
Traditional French Provincial architectural style

93. Chatham University (Eden Hall) – Pittsburg PA (USA)
The world’s first fully sustainable campus in higher education
SCHOOLS

96. M Power Yoga – Baltimore MD
state-of-the-art acoustical radiant ceiling system
FITNESS & WELLNESS CENTERS

98. MULTIFAMILY
Merville – Jesolo (Italy)
Architects:
Gonçalo Byrne Arquitectos
Pedro Sousa TMA

99. Final results

100. Mechanical Room Controls

102. MULTIFAMILY
(Beijing, China)

104. MUSEUMS
Armani Museum – Milan (Italy)

106. THANK YOU!