14 points every architect, engineer,
contractor and their clients should know about building
science - sample slides.
support visit our
three day integrated design program has
over 2100 slides illustrating architectural, interior design
and HVAC engineering principles which contribute to
indoor environmental quality and
energy allocation for
conditioning the occupants and building.
The following course materials on building
theory are samples from the lecture and based on a Steven Covey principle of "Begin
with the End in Mind". They are a very small but important sample of the Covey
principle and are provided here to give you an idea of what
kind of materials we'll be discussing during the program.
The course is also registered with AIA and participants can
earn up to 21 Learning Units.
For more sample slides visit our list of training modules.
This principle is so easy to say but oh so difficult to
manage in real life. Think about all the problems
associated with buildings and most will come down to
addressing the inward and outward flow of mass and
The driving gear on enclosures is balance - a balance in
mass and energy. On a macro scale it’s the elements of
earth seeking equilibrium. Wet goes to dry, hot goes to
cold, high pressure goes to low pressure. On a micro
scale occupants try to control this ever seeking
equilibrium in part with the building enclosure.
Figure 3: Think of the enclosure as a
gauntlet...as it steps in the way of energy and mass
seeking equilibrium it becomes
a filter, sponge and capacitor; capturing gases and
particulate, ad/absorbing moisture and gases and storing
energy in the form of heat.
Figure 4: The relationship between the
outdoor climate and indoor climate is dynamic; and we
the enclosure to be a governor of sorts – to knock
down the extremes so we have a reasonable chance at
creating indoor climates suitable for human occupancy.
However, industry is very good at testing those limits
with poor architecture, bad interior design and
inadequate HVAC systems; and it shows up in poor indoor
environmental health which contributes to lost
lower academic scores and unsustainable energy
Figure 5: Improving enclosure performance
requires us to understand the hierarchy of damage
functions. At the top of the list is moisture and it
matters not if it is a liquid gas or solid. Moisture
allergens and causes material damage. Heat is next
with UV light and ozone. These three are destructive as
they break down materials into gases and
particulate. All four lead to poor indoor
environmental health related to indoor air quality and
thermal comfort and increase the maintenance and
operating costs for the owners/occupants.
Building analysis tools such as finite element
analysis allow us to model building elements in their
environment. Shown are three slides from a yearly
simulation of ground temperatures for a building in
Calgary, Alberta, Canada. During the course we’ll run
the entire model to show you what thermally occurs at
various depths along a foundation wall and slab over an
entire year. How does this impact buildings? We'll
discuss this at length in the course.
Figure 7: We think it helps to look at
enclosures as outdoor clothing and gear. It matters
not if the assembly is a wall, roof or slab - the same
forces of nature are applied...inside wants out and
outside wants in. We don’t want the enclosure to sweat,
nor do we want it to stink and we don’t want it to break
down into respirable products. Choosing enclosure
materials and system to keep it warm, dry and ventilated
is no different than choosing cold climate clothing and
gear to keep you warm, dry and ventilated.
Figure 8: Ventilating a building takes
pressure…more specifically differential pressure. In the
old days when energy was cheap and materials of
construction were more eau natural it worked to some
rely on the differences between the inside and outside
to move air through at an undefined rate to dilute the
indoor pollutants. But that philosophy doesn’t work
today. Energy is not cheap and it’s going to get more
expensive. Air flow travels over less natural materials and
synthetic products in buildings. We can no longer rely
on leaky buildings so we have to “build tight and
ventilate right” and that takes pressure induced by
fans. You need fans to suck bad air out and fans to
bring outdoor air in and they should be somewhat
balanced. Unbalanced pressures can create problems for the
building and occupants....oh and yes the heat from the
exhaust air should be recaptured and used to preheat the
incoming air (see
Figure 9: Unbalanced pressures on
buildings can be imagined with the simple use of a
plumber’s plunger. You know when you push down on a
plunger it increases the outbound flow of mass, and when
you pull back you increase the inbound flow of mass. If
the plunger is sealed against a surface it can act like
a “pump” – a diaphragm pump to be more specific. Wind
pressures, stack effect and mechanical fans will have
the same effect on the enclosure as if you were pushing
or pulling on a plunger. When you push on an imaginary
plunger attached to the inside of a building you move
air mass from the inside to the outside which lowers the
internal pressure which means outside air mass at a
higher pressure will want to come inward - and it will
do that through cracks in the building...the opposite is
true when you pull back on the plunger. That air flow is
uncontrolled which means if it is hot, cold, moist and
contaminated it will become an energy, air quality and
thermal comfort problem.
Figure 10: Uncontrolled air flow
moving from the inside to the outside creates all sorts
of problems. One of the more common issues with the
outward flow of warm moist air is condensation. Should
air with sufficient moisture come in contact with a
surface of a suitable cold temperature it will condense.
Condensation on windows is a visual indicator of what
could also be occurring within the wall, floor and roof.
You can smell the problems with musty odours and see the
results of this with mould and mildew, staining and ice
dams at roof edges. Sometimes all it takes to create
condensation is the use of a
Figure 11: Keeping the outside out
and the inside in – is not that complicated in
principle. Take a good old Tilley hat designed to
keep the sun and rain off your head, face and neck.
Houses built without a hat have sun and moisture
problems. House with wide brims have fewer problems. I
say better to have “dry hat hair” than rotten skin
cancer nest pas?
Figure 12: Tomas Auer and Geoff
McDonell are two engineers who get that buildings should
do the bulk of the heavy lifting when it comes to
regulating heating and cooling for occupant comfort.
Both get the insanity of solving thermal problems with
mechanical solutions when better alternatives are
available. Most thermal problems solved today with
combustion or compression can be solved with stuff that
has no moving parts, doesn’t need to be fed calories
(i.e. gas, oil, coal, wood) and requires little to no
maintenance (i.e. mechanical therapy). That stuff is insulation,
caulking and good windows. Above FEA study we did with
the inside surface temperatures and heat flow based on
various amounts of insulations. Notice a thicker wall
has less energy flow which results in a warmer surface.
Warm indoor surfaces in winter and cool indoor surfaces
in summer are good....poor insulation destroys warm
winter surfaces and cool summer surfaces.
Figure 13: Warmer surfaces in
winter and cooler surfaces in summer takes us back to
our discussion on
mean radiant and
operative temperature and the meaning of "radiant
based HVAC". Solving operative temperature
problems with insulation is good because it improves
comfort while reducing the use of energy while lower
operating and maintenance costs. People get better
academic scores and have higher productivity when they
are in environments that are comfortable.
Figure 14: Windows are good,
windows are bad. Too much and you feel like you’re
inside an Easy·Bake Oven. Too little and you get sensory
deprivation. Selecting windows is an art and a science
and we’ll show you how to do both.
So there you have it, a few sample slides
from our building science lecturer...just a hors d'oeu·vre
from our library of over 2100 slides addressing a small
but important element of integrated design and
based HVAC systems. In the
three day program we will get into this and a whole lot
more? How much more? Well just follow the links to the
other parts of our website and you’ll get a feel for the
scope of materials that we’ll be covering.
See you soon.
Registered Engineering Technologist - Building
construction (ASET #8167)
Professional Licensee (Engineering) - HVAC (APEGA
Building Sciences / Industry Development
ASHRAE Committees: T.C.61. (CM), T.C.6.5 (VM), T.C. 7.04
(VM), SSPC 55 (VM)
ASHRAE SSPC 55 - User Manual Task Leader
Note: The author
participates on several ASHRAE and other industry
related committees but be advised the materials and
comments presented do not necessarily represent the
views of these societies, only the president of the
society or nominated representative may speak on behalf
of the organization.