Explore the ways to address indoor environmental quality with various heating and cooling systems. Hydronic heating/cooling and forced-air hybrid systems are an excellent way to address the complex topic of IEQ. It also discusses the future of IoT control systems that can help orchestrate and manage healthy indoor environments.

1. HRAI ANNUAL MEETING
Integrating Hydronics with Indoor Environmental Quality

2. /
- Max Rohr
- REHAU Academy Manager
- Max.rohr@rehau.com
Integrating Hydronics with Environmental Quality
226-August-2019

3. /
Integrating Hydronics with Environmental Quality
326-August-2019
Agenda
• Explain the complexity of quantifying comfort.
• Identify various heat transfer and distribution
options.
• Analyze radiant heating and cooling hybrid
systems.
• Describe the future of IoT IEQ controls.

4. /
What is Indoor Environmental Quality (IEQ)?
- Indoor environments are highly complex and building occupants may be exposed to a variety of
contaminants (in the form of gases and particles) from office machines, cleaning products, construction
activities, carpets and furnishings, perfumes, cigarette smoke, water-damaged building materials, microbial
growth (fungal, mold, and bacterial), insects, and outdoor pollutants. Other factors such as indoor
temperatures, relative humidity, and ventilation levels can also affect how individuals respond to the indoor
environment. (CDC.gov)
- IEQ is a portion of overall occupant comfort in buildings
Integrating Hydronics with Environmental Quality
426-August-2019

5. /
What is Indoor Environmental Quality (IEQ)?
- Well-designed heating and cooling
systems can play a part in
improving odors, sound, air and
thermal characteristics in a building
- Robert Bean has excellent
information on the topic of IEQ on
his website Healthyheating.com
Integrating Hydronics with Environmental Quality
526-August-2019

6. /
IEQ Scope for this Presentation
- In the context of heating and cooling:
- Indoor/outdoor temperature
- Humidity
- Ventilation
- Thermal comfort
Integrating Hydronics with Environmental Quality
626-August-2019
- Factors not addressed in this presentation:
- Lighting
- Toxins
- Asbestos
- Insects/pests
- Etc.

7. /
Who Defines IEQ in the Construction Industry?
- ASHRAE
- Standard 62.1: Ventilation for Acceptable Indoor Air Quality
- Standard 55: Thermal Environmental Conditions for Human Occupancy
- USGBC
- EPA
- ENERGYSTAR
- AHRI
- OSHA
- Local authorities having jurisdiction, related to energy and ventilation codes and standards
Integrating Hydronics with Environmental Quality
726-August-2019

8. /
ASHRAE Standards
- ASHRAE Standard 62.1: Ventilation for Acceptable Indoor Air Quality
First published in 1973 as Standard 62, Standard 62.1 specifies minimum ventilation rates and other measures
for new and existing buildings that are intended to provide indoor air quality that is acceptable to human
occupants and that minimizes adverse health effects. (ASHRAE.org)
- ASHRAE Standard 55: Thermal Environmental Conditions for Human Occupancy
Specifies conditions for acceptable thermal environments and is intended for use in design, operation, and
commissioning of buildings and other occupied spaces. (ASHRAE.org)
Integrating Hydronics with Environmental Quality
826-August-2019

9. THE COMPLEXITY OF QUANTIFYING COMFORT

10. /
Comfort is Not a Number on a Thermostat
Integrating Hydronics with Environmental Quality
1026-August-2019

11. /
Comfort is Not a Number on a Thermostat
- The six primary factors for thermal
comfort according the ASHRAE 55:
- Metabolic rate
- Clothing insulation
- Air temperature
- Air speed
- Humidity
- Radiant temperature
Integrating Hydronics with Environmental Quality
1126-August-2019
The Center for the Built Environment,
University of California Berkley
http://comfort.cbe.berkeley.edu/

12. /
Human Heat Transfer
- Heat emission from the human body at rest (diagram)
- Radiant cooling reduces the surface temperatures in a room, which
draws more heat from our bodies via radiation
- A New Buildings Institute survey of 1,645 building occupants found,
“In a space using a radiant system, a person has a 66% chance of
having an equal or higher temperature satisfaction than in an all-air
conditioned building.”
Integrating Hydronics with Environmental Quality
1226-August-2019
Radiation
~62%
Respiration and
evaporation
~25%
Conduction
~3%
Convection
~10%
Healthyheating.com
Energy Use, Occupant Surveys and Case Study Summary: Radiant Cooling and Heating in
Commercial Buildings, New Buildings Institute and Center for the Built Environment, 2017

13. /
Human Heat Transfer
- What do people feel cold in the frozen food aisle?
- What is the air temperature?
Integrating Hydronics with Environmental Quality
1326-August-2019
Radiation
~62%
Respiration and
evaporation
~25%
Conduction
~3%
Convection
~10%
Healthyheating.com

14. /
Radiant Mean Temperature Example
- Let’s say you walk around a corner from the
sunny side of a building to the shady side
- Assume it is 40°F (4°C) day with no wind
- Do you feel warmer in the sun and colder in
the shade?
Integrating Hydronics with Environmental Quality
1426-August-2019

15. /
Surface Temperature Limitations
- According to ASHRAE Standard 55 (Thermal Environmental Conditions for Human Occupancy),
to keep humans comfortable the floor temperature should:
- Stay below 84°F (29°C) in heating mode
- Stay above 66°F (19°C) in cooling mode
Integrating Hydronics with Environmental Quality
1526-August-2019

16. /
Fresh Air
- ASHRAE Standard 62.1 provides guidelines for the amount of fresh
air that must be introduced into a space, among many other things
- If you can smell burnt popcorn a few days later in your kitchen, is
that a good sign?
Integrating Hydronics with Environmental Quality
1626-August-2019

17. HEAT TRANSFER AND DISTRIBUTION OPTIONS

18. /
High-performance Building Design
- Start with a tight building
- Work with the best regional fuel option
- Maximize renewable sources, when possible
Integrating Hydronics with Environmental Quality
1826-August-2019

19. /
What is Radiant?
- Heating or cooling a space by circulating
a water-based medium through a
network of PEX pipe embedded in a
surface
- A method of conditioning a space that
uses liquid instead of air to transport
energy
Integrating Hydronics with Environmental Quality
1926-August-2019

20. /
Principles of Radiant Heating
- Heat radiates from the network of PEX in a surface,
warming people and objects in the space above
Integrating Hydronics with Environmental Quality
2026-August-2019
Occupied
space
Radiation
Floor
covering
Concrete
PEX
Insulation

21. /
Principles of Radiant Cooling - Reverse the Process
- In cooling mode, the network of PEX is used to
absorb heat out of the occupied space by
circulating cooled water instead of warm water
- Warm objects always radiate to cool objects,
regardless of direction
Integrating Hydronics with Environmental Quality
2126-August-2019
Occupied
space
Radiation
Floor
covering
Concrete
PEX
Insulation

22. /
Energy-Efficient Distribution Example
Integrating Hydronics with Environmental Quality
2226-August-2019
53,000 Btu/h load
1,068 W blower, 3/4 hp
53,000 Btu/h load
87 W circulator
Radiant cooling base component
hydronic 3-speed circulator
Forced-air base component
3/4 hp blower fan
Btu/h
watts
Distribution efficiency =
= 609.1 Btu/h / watt = 49.6 Btu/h / watt
(7.0 gpm at 12 feet of head, 15°F delta T) (3/4 horse power, 120V, 8.9 Amps)
12 times more
efficient, in this case!

23. RADIANT HEATING AND COOLING HYBRID SYSTEMS

24. /
Heating and Cooling Systems
- What heats and cools the building that you work in?
Integrating Hydronics with Environmental Quality
2426-August-2019

25. /
Radiant Systems
- Heating: a way to heat a space by
increasing the average surface
temperature of the room
- Cooling: a way to absorb heat from a
space by reducing the average surface
temperature of the room
- Energy efficient and comfortable
- Often part of a hybrid system with
forced-air
Integrating Hydronics with Environmental Quality
2526-August-2019

26. /
Why are Hybrid Systems Common?
- Fresh air
- Ventilation is required to meet a building’s fresh air requirements; check local codes for specifics
- Latent cooling loads
- Radiant cooling systems only address the sensible loads. Forced-air components exist to counter humidity
from outside air and from occupants within a building (latent cooling)
- Heating-to-cooling changeover
- In some applications, it is desirable to have a system that is capable of handling quick shifts in occupancy
and transient loads
Integrating Hydronics with Environmental Quality
2626-August-2019

27. /
Cooling Variables for Occupants
Integrating Hydronics with Environmental Quality
2726-August-2019
- High air velocity
noise is possible
- More frequent
temperature shifts
- Lower air velocity
noise
- Even distribution of
temperature in the
space from the
radiant surface
Air-based System Radiant Cooling Hybrid System

28. /
Hybrid Systems - Decoupling the Sensible and Latent Cooling Loads
- Air-based cooling and ventilation systems take
care of the latent cooling load, and may provide
additional trim load cooling, when needed
- Ventilation is required to meet a commercial
building’s fresh air requirements, staying
consistent with indoor air quality standards
detailed in ASHRAE Standard 62.1
- Downsized ventilation components may be
possible, since the radiant cooling is efficiently
taking care of more of the sensible cooling load
Integrating Hydronics with Environmental Quality
2826-August-2019

29. /
Energy Efficiency Studies
- A New Buildings Institute research study of site energy use in 23 radiant buildings found:
- Radiant buildings are more energy efficient than 90% of comparable buildings, with two-thirds
receiving an EnergyStar score of 90 or above.
- “This mirrors the findings in the largest database of Zero Net Energy buildings where more than half of
Zero Net Energy buildings in North America use a radiant system.”
Integrating Hydronics with Environmental Quality
2926-August-2019
Energy Use, Occupant Surveys and Case Study Summary: Radiant Cooling and Heating in Commercial Buildings, New Buildings Institute and Center for the Built Environment, 2017

30. /
Infosys SDB1 Internal Energy Audit Report
“The radiant cooling system was 33% lower in energy
consumption compared to the conventional air-
conditioning system.” Apr 2011 to Mar 2012.
Integrating Hydronics with Environmental Quality
3026-August-2019
ASHRAE Journal, May 2014

31. /
How do the Occupants use the Space?
- Why people open windows in a skyscraper in the middle of winter?
Integrating Hydronics with Environmental Quality
3126-August-2019

32. /
What are Ideal Applications for Radiant?
- Radiant heating:
- Residential and commercial
- Libraries, schools, buildings with many zones
- Any building with big overhead doors, like hangars, fire stations and shipping areas
- Areas that struggle with unintended stratification, like an atrium
- Radiant cooling:
- Commercial, new construction with commercial-grade temperature and humidity controls
- Residential projects must account for the latent load as if ASHRAE 55 and 62.1 (commercial standards)
applied
Integrating Hydronics with Environmental Quality
3226-August-2019

33. THE FUTURE OF IOT IEQ CONTROLS

34. /
What do Traditional Controls Monitor?
- Traditional thermostats
- Temperature
- Humidity
- Radiant heating and cooling specific
- Floor temperature sensor near the surface of the
thermal mass
- Supply and return fluid temperature sensors in the
piping network
- Necessary information for proper radiant cooling
control:
- Accurate temperature and humidity in each zone
Integrating Hydronics with Environmental Quality
3426-August-2019

35. /
What Additional Measurements Could be Taken?
- CO2
- Pollutants (VOCs, CO, radon, etc.)
- Dust
- Sunlight, solar heat gains
- Occupancy and location
- Motion
Integrating Hydronics with Environmental Quality
3526-August-2019

36. /
What Role Does IoT (Internet of Things) Play?
- IoT controls don’t fix problems
- They may be able to help measure more factors
Integrating Hydronics with Environmental Quality
3626-August-2019

37. /
The Future of IoT Controls
- Faster identification of the people in a space
- What are the occupants doing?
- How do all the factors intertwine?
- Sensors are readily available for the common IEQ measurements, the intellectual property to develop a controls
sequence of operation is the valuable commodity
- Comfort isn’t a number on a thermostat, even if it is a connected thermostat
Integrating Hydronics with Environmental Quality
3726-August-2019

38. /
What is Happening Outside?
- In a perfect controls system, would
different ventilation decisions be made
based on outdoor air quality?
- Allergens
- Smog
- PM2.5 warnings
- Forest fires
- CO levels
Integrating Hydronics with Environmental Quality
3826-August-2019

39. /
University of Chicago
Integrating Hydronics with Environmental Quality
3926-August-2019

40. /
Summary
• Explain the complexity of quantifying comfort.
• Identify various heat transfer and distribution options.
• Analyze radiant heating and cooling hybrid systems.
• Describe the future of IoT IEQ controls.
Integrating Hydronics with Environmental Quality
4026-August-2019

41. /
- Max Rohr
- REHAU Academy Manager
- Max.rohr@rehau.com
Integrating Hydronics with Environmental Quality
4126-August-2019

42. Thank You!