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Fundamentals of indoor environmental quality / thermal comfort and air quality solutions using radiant based HVAC

Part I - Introduction
Part II - Hormones


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Terms:

Metabolism: refers to all chemical reactions occurring in the body.

Catabolism: break down of complex molecules and are exergonic, i.e. releases energy (such as heat).


"Ultimately one of the difficulties in discussing thermal comfort is that this definition of “condition of mind” sits, "at the crossroads of physics, physiology, psychology, culture, and climate (Solomon, 2011);" and as I like to point out, it does so amongst a competitive industry driven by public relations, marketing, and sales teams all offering products and services related to a term that it doesn’t really understand nor can it accurately define."


"....the perfect heating and cooling system would be based principally on human comfort factors."
Michael McDonough
Architect


"...the knowledge of the temperature contributes to our feelings of comfort and acceptability."
F. Rohles,Jr., Ph.D.
Professor Emeritus,
Kansas State University


"We can detect temperature changes of 0.01C in the hypothalamus where body temperature is controlled"
Professor David Hanes
Sonoma State University


"...the Academy of Neuroscience for Architecture came to be when Jonas Salk had stimulated Norman Koonce and Syl Damianos [then president and chairman of the American Architectural Foundation, respectively] to get someone to explore the brain’s role in how architecture affects human experience. What Salk said was...“Architects should have a better understanding of human experience with architectural settings.”
Academy of Neuroscience
for Architecture


No matter what you read in literature you simply can't buy comfort -  you can only buy combinations of buildings and HVAC systems which if selected and coordinated properly can create the necessary conditions for your body to perceive comfort.


"Thermal comfort mediates behavioral modification of heat loss, the most important thermoregulatory response in humans. Thermal comfort is determined by skin-surface temperature, not by tissue heat content, cutaneous heat flux, or central temperature.  However, comfort produced by a local thermal stimulus depends both on the location of the stimulated skin and the rate of temperature change. For example, facial skin is five times as sensitive as other skin surfaces; furthermore, rapid changes in skin temperature produce approximately five times the response of slow changes."  Sessler (M.D.), D., Moayeri, A., Skin-Surface Warming: Heat Flux and Central Temperature, Anesthesiology, 73:218-224, 1990


We don't inhale comfort we sense it through our skin...yet 99.99% of all thermostats exclusively measure air temperature and fail to measure what we experience.


"...design is about meeting real human needs and not just creating attractive or dramatic surroundings."
Anita Baltimore, FASID


"Heat loss occurs primarily from the skin of a patient to the environment through several processes, including radiation, conduction and convection, and evaporation. Of these, radiation is most significant and accounts for ~60% of total heat loss. Radiation is emitted in the form of infrared rays, a type of electromagnetic wave. Heat from core body tissues is transported in blood to subcutaneous vessels, where heat is lost to the environment through radiation." Ref.: Dr. Daz, Dr. Becker. Thermoregulation: physiological and clinical considerations during sedation and general anesthesia. Anesth Prog. 2010;57:25–32


"...to deny or ignore the psychology involved in comfort measurements is not only short-sighted, but treats the human subject as a machine, which it is not."
F. Rohles,Jr., Ph.D.
Professor Emeritus,
Kansas State University


"The skin is the main heat exchanger of the body. The skin temperature is determined by the core temperature and by the environment (temperature, humidity, air velocity). Thus the shell temperature is governed by the needs of the body to exchange heat energy"
Zubieta, P., New Human Physiology, 2nd Edition, Chapter 21: Thermo-Regulation, Temperature and Radiation


Expecting even the most expensive 'retail' thermostat to compete with thousands of skin sensors which measure radiant, conductive and evaporative losses is...well just plain silly.


“The most commonly used indicator of thermal comfort is air temperature – it is easy to use and most people can relate to it. But although it is an important indicator to take into account, air temperature alone is neither a valid nor an accurate indicator of thermal comfort or thermal stress.” The Health & Safety Executive, UK.gov


"The absence or presence of heat is one of the primary environmental factors affecting human comfort. We pay enormous attention to the five main sensory organs in our bodies, yet often overlook our true sixth sense, thermal sensitivity." Andrew Marsh Ph D, B. Arch. (Hon)


"No matter how sophisticated, a space thermostat which doesn't sense what, where and how we sense is still a barbaric ambassador to the HVAC system."


“The quality of housing conditions plays a decisive role in the health status of the residents, because many health problems are either directly or indirectly related to the building itself, the construction materials that were used, and the equipment or the size or structure of the individual dwellings.”
The World Health Organization


"Homeostasis (thermal regulation) is essential for the maintenance of health and its breakdown results in disease."
Faculty of Health Sciences University of Sydney


“…a rational calculation of heating and air-conditioning systems must begin with the conditions for comfort.”
Prof. P.O. Fanger, Ph.D.


Long before the conditioning of people and buildings became focused on selling equipment - old dead people like Hippocrates, Vitruvius, Nightingale, Galton, Bedford and Vernon taught us that there is no separation between the building and health sciences. They taught us that it matters not if an unoccupied building is cold, damp, dry, drafty or hot...it only matters when it is occupied and thus all design should focus on the needs of the people and not the needs of the building.

When we do this design from the inside out - literally starting with human factor design, good buildings will naturally follow.


"I think it's reasonable to say that for a sighted person, the stimulus of what one sees when looking at a building tends to over-ride what one feels through many of the other senses..."
Interview with visually impaired writer Rebecca Maxwell, Beyond Appearances - Architecture and the Senses, The Comfort Zone hosted by Alan Saunders, Nov. 2004

 

Thermal Comfort: Indeed a Condition of Mind (in simple terms)
Copyright (C) 2012 Robert Bean, R.E.T., P.L. (Eng.) and content providers

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Coming soon: Epinephrine and thermal regulation.
 

Part I - Introduction

Ok…are ya' ready…this is the human factor material intimately tied to thermal comfort and better building performance but typically not taught in engineering, architectural and related trade programs - but it should be…it’s one of the missing links between the health sciences and building sciences.[i],[ii]

In my world, human anatomy, physiology and psychology as it relates to indoor environmental quality is the coolest stuff ever (pun intended). I’ll place this overview on thermal comfort and anatomy and physiology in front of you in way that you can understand it…it is simplified enough to make ardent medical school professors roll their eyes but at least you the everyday Jill and Jack from the world of construction will understand at a very basic level what thermal comfort is from the perspective of the human body.

By the way...I’m writing this now so you our loyal readers can explain it later to small children. Why? So when they grow up, they have the ammunition to lead the HVAC industry back over to the health sciences side where thermal comfort as well as indoor air quality began a long time ago…are ya ready?[iii],[iv]

In the beginning...

Ok first things first…from the inside of your body’s perspective, thermal comfort does not come in a furnace or air conditioner nor is it a thermostat reading of 72F (22C)…as much as consumers have been led to believe that you can buy thermal comfort - you can't...from a physiological point of view thermal comfort is not synonymous with so called “thermal comfort equipment”. If you think people are successfully buying quality indoor environments tied to thermal comfort and indoor air quality equipment you need to spend some time answering phone calls at a mechanical contracting business or spend some time with the EPA and Energy Star programs or reading the thousands of posts uploaded to the always entertaining online HVAC help forums. If you want the statistics spend some time reading reports from past and present members of ASHRAE SSPC 55 and member colleagues over at CIBSE and REHVA.

But we're here to talk about thermal comfort, so what specifically is it?

As stated in countless scientific research papers and texts on indoor climate engineering, “thermal comfort is a condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation”…that’s it – that’s how the international community of researchers in human physiology and indoor climate engineering define thermal comfort and it’s how you should define it as well.[v],[vi]

Condition of Mind

So let’s start with your mind and more specifically the organs of your brain which makes you think to yourself, “self, you know what, I’m feeling hot” or you might say, “is it cold in here or is it just me?” Yes it is you and your conscious and subjective perceptions can and do happen simultaneously while your body is preparing to sweat or shiver and/or reaching for a fan or sweater.

In the first reaction you are actually having a conscious thought about how you feel…this comes from a part of your body which most people are familiar with called the Cerebrum (Figure 1 below, left) and more precisely the Parietal lobe (Figure 1 below, right) and it’s somatosensory region.[vii]

CerebrumThe Parietal lobe

Figure 1. Cerebrum (left image, shown in red) and more precisely the Parietal lobe (right image, shown in red) containing the somatosensory region. It is in the somatosensory region, a small section within the Parietal lobe where you perceive temperatures. Image credit: BodyParts3D, The Database Center for Life Science licensed under CC Attribution-Share Alike 2.1 Japan

The cerebrum is what most people imagine when they think of the brain…it’s the large dome shaped mass sitting just under your skull and it controls and integrates motor, sensory, and higher mental functions, such as thought, reason, emotion, and memory.

In a second reaction your body may already be responding at a below conscious level by developing goose bumps, shivering or sweating; just like blinking or developing rashes, you simply have little to no control over how the body automatically responds to negative thermal stimuli.

Below conscious processes related to thermal comfort are part of the autonomic nervous system and the endocrine system. These two systems act together to coordinate functions of all body systems.[viii] For our purposes of discussing thermal comfort, think of the former as part of your own electrical control system and the latter as part of your own internal pharmacy.

Two halves of the Thalamus

Figure 2. Two halves of the Thalamus (mid brain, shown in red). It can be thought of as your own biological 'air traffic controller'.  Image credit: BodyParts3D, The Database Center for Life Science licensed under CC Attribution-Share Alike 2.1 Japan
 

So far so good?

Well deep inside your brain, sitting at the very top of your spinal cord right after the brain stem, is an organ called the, “Thalamus” (Figure 2, above). Think of the Thalamus as grand central station…your own biological air traffic controller in that it monitors and processes information that travels from the Netherlands of your body back through your electrical and chemical systems into your brain. Specifically we’re talking about your nerves and hormones but we’ll come back to these in a few moments.

As grand central station, the Thalamus is connected to your Cerebrum where, “you think therefore you are”, i.e. where conscious thought takes place. The Thalamus is also connected to the spinal cord through the brain stem and to another organ called the Hypothalamus (Figure 3 below). The Hypothalamus is then connected to your Pituitary gland located below the Hypothalamus; and the Pituitary connected to your Thyroid gland located along side your windpipe. These organs are crucial to your ability to sense, perceive and control body temperature and are part of the anatomy known as the endocrine system.

Ok…a bunch of new parts so let’s describe how they fit into this “condition of mind”.

Hypothalamus (shown in red) and Pituitary

Figure 3. Hypothalamus (shown in red) and Pituitary (hanging below and attached to the Hypothalamus). Image credit: BodyParts3D, The Database Center for Life Science licensed under CC Attribution-Share Alike 2.1 Japan

Who's who and what does it do?

The Hypothalamus (Figure 3), literally, “located below the Thalamus” and inward behind your eye sockets, is descriptively, “the operator” of your own internal thermostat. That internal thermostat is known as the Pituitary gland (Figure 3 and 4) and it is connected to the Hypothalamus. It is the Hypothalamus, a sugar cubed size organ along with the peanut sized Pituitary gland which controls your core body temperature. The Hypothalamus is also involved in controlling emotions like anger so when you are cold and mad at being cold you can blame it, rather than your HVAC service providers!

When you become cold you can take conscious actions to raise your temperature. You can attempt to retain heat by increasing insulation and reducing convective losses – i.e., a sweater with a wind breaker, i.e., much like the principles of efficient buildings. You can try to gain heat by sitting in the sun. You can also increase your metabolic rate by increasing your physical activity (shuffling, rubbing your skin and exercising body parts) or by reducing your exposed body area by huddling. But here’s what is happening below conscious at a physiological level through your Hypothalamus, Pituitary and Thyroid glands known as the HPT axis (Figure 4 below).

As part of your thermal comfort pharmacy the Hypothalamus dispenses to the Pituitary gland (your thermostat) a hormone called “Thyrotropin Releasing Hormone” or TRH for short. This action by the Hypothalamus would be akin to you turning up the thermostat. TRH is taken in by the Pituitary gland as chemical directions to release to the Thyroid another hormone called, “Thyroid Stimulating Hormone” or TSH for short (Figure 4, below).
 

Endocrine and Autonomic Nervous System (ANS)

Figure 4. Endocrine and Autonomic Nervous System (ANS). Showing the Thalamus and HPT axis and T3/T4 hormones. Adapted/Image credit: Dorling Kindersley, used with permission.
 

TSH dispensed by your Pituitary induces the small butterfly shaped Thyroid gland (located alongside your windpipe just below your larynx) to release iodine based thyroid hormones T4 and T3 into your blood stream (Figure 4)…you can think of these two hormones as chemical “keys” which unlock cellular processes related to such things as blood flow, digestive processes, respiratory rate and muscular activity…when cells related to these process are opened by the hormones, it increases the body’s conversion of oxygen and calories to energy. The release of energy is done along side a process called thermogenesis, which raises the basal metabolic rate of which heat is a by-product.

In this regard you can imagine the Thyroid as a boiler gas valve regulated by the Pituitary gland (the thermostat) in modulating the flow of the chemical fuel supply to target cells with receptors that match up to the T3 and T4 hormone keys. It's little more complicated than that but you get the picture.


Feedback

But how does your body know when to stop having perceived thoughts of cold or physical manifestation of cold through goose bumps and shivering? Good question…this is where your nerves and hormones and hormones as neurotransmitters come in as feedback to your control system. Let’s get the fast acting nervous system out of the way first.

Distributed throughout your body and embedded within your skin are thousands of nerve endings which serve as thermal sensors reacting to changes in blood temperature and changes in skin temperature. There are separate sensors for hot and cold temperatures and they should not be confused with a different group of sensors related to pain which may occur from skin burns or freezing body parts.

In all there is something like 165,000 (+/- a few thousand) thermal sensors in your skin.[ix] For impact consider that the average human has a skin area of approximately 16 ft2 (1.5m2) to 20 ft2 (1.9m2) or about the hood area of a small to mid-size car.[x] Now imagine all those thousands of thermal sensors sprinkled over your car hood and compare that thought to an image of your single furnace thermostat in that great big home or office area...can you see how man’s attempt at using a single air based electromechanical device as our ambassador to an HVAC system pales in comparisons to the elegance and beauty of the human body’s own thermal control system?

In any event these skin nerve endings fire off electrical pulses through your nervous system up into your Thalamus at a rate based on the thermal profile they are sensing. Now here’s a very amazing consideration…these nerve endings are not distributed in a homogenous pattern as one might imagine, but in higher concentrations in the exposed areas of the body, that being your feet, ankles and calves, hands and wrists and neck, face and head. Whatever your beliefs are in the existence of mankind you have to find that information fascinating given how a large percentage of the world population dresses itself with exposed extremities.
 

Brain imaging during skin cooling and heating

Figure 5. Brain imaging during skin cooling and heating. Used with permission.4 

The skin: the number one thermal sensory organ for the indoor environment.

At this point you should now appreciate why people don’t actually feel the heat loss or gain of the building but rather the heat loss and gain in their skin.[xi]  At roughly 7% of your body weight, the skin is the number one organ responsible for measuring changes in temperature in relation to the surrounding environment.

Under normal heating conditions and metabolic rates typical of home and office, the sensible heat transfer from the body to the indoor environment is dominated by radiation to and from your skin (see side bar), which stores approximately 8% of the body's blood supply. In part, it is the regulation of blood flow to your skin which facilitates cooling or retention of body heat.

As a side bar; radiant transfer as a key comfort regulator is the reason why I have stated multiple times before that building codes need to drop the reference to controlling air temperature and replace it with controlling mean radiant temperature (MRT); in fact if building codes did this, thermal performance in new buildings would be mandated to change considerably and for the better.

Requiring architects and builders to deliver acceptable mean radiant temperatures instead of air temperature is a potentially simple and meaningful enactment which could be made by regulators towards energy sustainability.

Ok let’s get back to your nerve endings, firing off signals into your spinal cord up through your brain stem into grand central station (the Thalamus), where the nerve ending firing rate is compared to the genetically programmed firing rate required for thermal homeostasis - that being a rate equivalent to a core temperature approximately between 97F+/- (36C) and 98.6F+/- (37C).[xii]
 

Figure 6. Receptor firing rates as a function temperature. Adapted from Zhang, H., Arens, E., Local cooling/heating for energy-efficient thermal comfort in vehicles, University of California at Berkeley see (Hensel,1980)

If in general, the integrated pulse rate of sensors is approaching the acceptable range, then the mind knows that at least at the exterior of the body, the environment and/or the heat production measured as temperature at the skin is resulting in a rate recognized by the Thalamus as being acceptable for thermal comfort conditions - regardless of what the room thermostats says.[xiii]

We should also point out that local sensors (say for example in the feet) that deviate strongly away from the norm, identify local discomfort conditions. So it’s not enough to say that general consensus is acceptable when clearly there will be conditions where the Thalamus will deal with conflict. This happens when floors are too cold or in the presence of strong radiant asymmetry, drafts and temperature stratifications. 

At the same time as these sensors are firing off signals to your Thalamus, the level of T3 (triiodothyronine) and T4 (thyroxine ) hormones are being monitored by your Hypothalamus and should these returning hormone concentrations indicate warming (coming back at a higher value) then the Hypothalamus reduces its release of TRH hormone which the Pituitary interprets as a signal to reduce the levels of TSH to the Thyroid which in turn reduces the release of the T3 and T4 hormones which returns your metabolic rate to its normal levels. Also as noted in ASHRAE Fundamentals Handbook, Chapter 9, Thermal Comfort, the Hypothalamus, “… has hot and cold temperature sensors and is bathed by arterial blood. Because the recirculation rate of blood is rapid and returning blood is mixed together in the heart before returning to the body, arterial blood is indicative of the average internal body temperature.”

In HVAC terms the whole process is akin to you adjusting a PID thermostat which controls a fully modulating gas valve on a boiler (well its more like fuzzy control logic but that's for another discussion).

It is the wonderfully coordinated processes between the nervous system and endocrine system which determines thermal comfort from the human factor perspective. No matter what you read in sales literature you simply cannot buy thermal comfort -  you can only buy combinations of buildings and HVAC systems which if selected and coordinated properly can create the necessary conditions for your body to perceive thermal comfort. 

Last thoughts

In my book thermal comfort control is the most elegant system in the human body…it does it without buttons, knobs, batteries, combustion or compression…and it does it without a complicated multi page programming manual printed in number 8 font; and so long as you have no disorders and stay healthy it along with adaptive measures and environmental controls will effectively control your body temperature 24/7/365.

Thermal comfort is indeed a condition of mind and we greatly need to teach those in the thermal comfort industry that; no matter how zippy or how efficient the equipment, if HVAC along with the building enclosure can’t create a set of conditions acceptable to the majority of minds in the space it should be called something other than a thermal comfort system.


Notes:
[i] See James E. Woods, Ph.D., P.E., ASHRAE Fellow remarks, Report of the Surgeon General's Workshop on Healthy Indoor Environment: January 12–13, 2005, National Institutes of Health, Bethesda, MD,
< http://www.ncbi.nlm.nih.gov/books/NBK44638/>
[ii] Canadian Building and Health Sciences Network – Proceedings,
< http://cbhsn-rcesbs.proteus.cisti.nrc.ca/eng/index.html>
[iii] Why your children? Because you and I will likely be dead before industry starts to teach this missing link at college and trade schools.
[iv] See early work by H.M. Vernon, M.D., and T. Bedford, D.Sc., Ph.D et al
[v] ANSI/ASHRAE Standard 55, Thermal Environmental Conditions for Human Occupancy
[vi] Rohles, Frederick H. Jr (2007), “Temperature and Temperament: A Psychologist Looks at Comfort,” ASHRAE Journal, 49 (February), 14-22 < http://bookstore.ashrae.biz/journal/journal_s_article.php?articleID=5>
[vii] Somato means, “body” so somatosensory is the, “body of sensations” or the place where the body perceives “sensations”.
[viii] Principles of Anatomy and Physiology, 13th Edition, by Gerard J. Tortora, Bryan H. Derrickson, Wiley & Sons, March 2011
[ix] A. Marsh, Ph.D. , SQU1
[x] See note xii.
[xi] B & K, aka LumaSense aka Innova literature.
[xii] Certain people who visit our website are known to have no grey matter in that they only think in black or white and 1’s and 0’s and haven’t figured out that in-between 1 and zero is an infinitesimal number of values so when they read a number on our website that doesn’t fit their exact world the get bent out of shape and send us nasty emails. Some day when they see the light I’ll teach them about fuzzy logic but until that time all we can do is offer up understanding and empathy
[xiii] See the studies by Rohles et al regarding the psychology of comfort - numerical values on thermostats can psychologically affect your perceptions regardless of what the body is physically sensing…weird stuff considering that color coded dials in cars don’t have the same effect. 


Images: 
Figure 1, 2 & 3,
BodyParts3D, The Database Center for Life Science licensed under CC Attribution-Share Alike 2.1 Japan
Figure 4, adapted from Dorling Kindersley, used with permission
Figure 5: See resource #4, used with permission

Resources:

  1. The Human Body Book, DK Publishing, 2007 Edition

  2. Principles of Anatomy and Physiology, 12th Edition, by Gerard J. Tortora, Bryan H. Derrickson, Wiley & Sons, March 2011/2012

  3. Hall, J., 2011. Guyton and Hall Textbook of Medical Physiology, Elsevier

  4. McAllen RM, Farrell M, Johnson JM, Trevaks D, Cole L, McKinley MJ, et al. Human medullary responses to cooling and rewarming the skin: a functional MRI study. Proc Natl Acad Sci U S A. 2006;103:809–13

  5. Egan GF, Johnson J, Farrell M, McAllen R, Zamarripa F, McKinley MJ, Lancaster J, Denton D, Fox PT. (2005) Cortical, thalamic, and hypothalamic responses to cooling and warming the skin in awake humans: a positron-emission tomography study. Proc Natl Acad Sci U S A .102:5262–5267.

  6. Title, Purpose and Scope of ANSI/ASHRAE Standard 55

  7. Turner, S., What’s New in ASHRAE’s Standard on Comfort, ASHRAE Journal, pages 42-48, June 2011
    H. Rohles , Temperature or temperament: a psychologist looks at thermal comfort. ASHRAE Transactions 86 1 (1980), pp. 5–13. 11.

  8. Solomon, N.B., The Comfort Zone, Architectural Record, McGraw-Hill, April 2011

  9. ASHRAE Bookstore: ANSI/ASHRAE Standard 55 Thermal Environmental Conditions for Human Occupancy

  10. Bailes, A., Naked People Need Building Science, Energy Vanguard, Dec. 2011

  11. Butler, D., Lessons Learned by a Reluctant Owner-Builder, Energy Vanguard, Mar. 2012

  12. Bean, R., The Big Picture: Enclosures, indoor environmental quality and HVAC systems cannot be treated as isolated and independent systems – they are in fact one of the same, Better Buildings – Beyond the Benchmark,  Fall 2011

  13. Bean, R., Thermal Comfort and Indoor Air Quality, 2012 Conference Slides – Online version (allow 120 seconds to load)

  14. Eccles, R., An explanation for the seasonality of acute upper respiratory tract viral infections. Acta Otolaryngol 2002; 122:183–191. <http://tinyurl.com/mndbpph>

  15. Johnson, C., Eccles, R. Acute cooling of the feet and the onset of common cold symptoms. Family Practice 2005; 22: 608–613. <http://fampra.oxfordjournals.org/content/22/6/608.full.pdf html>

  16. Eccles. R., Acute cooling of the body surface and the common cold. Rhinology, 40, 000-000, 2002 <http://tinyurl.com/kks92dc>

  17. Bean, R.,  Begin with the End in Mind, Commercial Building Products, March, 2012

  18. Mitchell, H., Can Going In and Out of Air Conditioning Cause Colds? How exposing the body to extreme temperature swings can lower our natural defenses (content expert, Prof. R. Eccles, director of the Common Cold Centre at Cardiff University in Wales) Wall Street Journal, Monday, August 19, 2013. Accessed August 23, 2013

     


Additional information:

"A resting adult produces about 350 Btu/h of heat. Because most of this is transferred to the environment through the skin, it is often convenient to characterize metabolic activity in terms of heat production per unit area of skin. For a resting person, this is about 18.4 Btu/h ft2 (50 kcal/hm2) and is called 1 met." 2009 ASHRAE Fundamentals Handbook, Chapter 9, Thermal Comfort.

"Skin is the principal organ for dissipating heat: the human body dissipates
approximately 85% of its heat loss through the skin under normal environmental
conditions (Zhang 2003)." Holopainen, R., A human thermal model for improved thermal comfort, Doctor of Science in Technology Thesis, Aalto University, VTT, December 2012

"...a state of thermoneutrality exists when the core and mean skin temperatures are 36.8C and 33.7C, respectively." Holopainen, R., A human thermal model for improved thermal comfort, Doctor of Science in Technology Thesis, Aalto University, VTT, December 2012


Related reading:

Bodily maps of emotions
Do I need an engineer? A Guide to HVAC/Indoor Climate Design Service Providers
Where will your indoor climate system score?
How to "ball park" your budget for indoor climate control.
Indoor environments: Self assessment
Built to code: What does it mean for consumer thermal comfort?
The Total Comfort System - The "Un-minimum" System
Thermal Comfort: A 40 grit perspective for consumers
Thermal Comfort: A Condition of Mind

Do-It-Yourself HVAC - Should you do it?
The Cost of HVAC Systems - Are You Paying Too Much for Downgrades?
Radiant Installations - The Good, Bad and Ugly
Thermal Comfort Surveys - Post Occupancy, Part I
Thermal Comfort Surveys - Post Occupancy, Part II

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