21 points every architect, engineer,
contractor and their clients should know about heat terminal
- sample slides.
support visit our
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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 heat
terminal units (HTUs) 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.
Figure 1: I don't know about you but
these old style heating devices (aka heat terminal units
aka HTU's) have a mystic aura about them that I really
love. I credit my good friend
for helping me to find my inner appreciation for these
Just north of our Calgary office are the guys from TWA
Panels who make chilled beams and radiant ceiling panels - a few of their products (above)
conditioning a classroom.
Figure 3: Michel Cinier says this about
his products (above), "The union of the best technology
and creativity for the Art of heating. Being surrounded
by beauty is a way of living." I agree...I've seen a lot
beautiful radiators in my days and these ones are up
there with the best."
Figure 4: I was privileged to have had a
private tour (courtesy of Tim Doran), of the
TACO HVAC Innovation & Development Center; on
display in the new facility are fine examples of how to
condition people and spaces. Shown above are low profile
radiators (left and right) and chilled beams (center). Photo Courtesy of Taco Inc.
Figure 5: I had been to the Taco plant
many years ago when we represented them in Southern
Alberta. I remembered this
wall radiator and swore the next
time I got back to the plant that I would take a picture
to show a industrial application for conditioning people
an spaces in a large manufacturing facility. So many
large facilities try to blow hot air down from the roof
which is an exercise in futility - it just doesn't have
to be that way with so many other better choices in
HTU's. Photo Courtesy of Taco Inc.
Figure 6: At one point or another in my
career I've worked with almost all of the radiant floor
heating manufacturers. For the past decade Uponor and I
have partnered up on various programs to communicate to industry the
importance of creating better human environments.
Without their support for industry education much of
what we see on the North American continent would likely
not be at the same calibre. Shown is one floor of a
multi-story building in Toronto, On., using
radiant floor cooling and heating. Perhaps one of
the best commercial installations I've seen. Also shown is a
prefabricated manifold and mixing station (foreground
and right side). This model came out of our own
manufacturing facility before we sold the plant several
years ago. Photo's courtesy of Uponor.
Figure 7: I don't recall the brand name
of these heat terminal units but they are an actual
fan/convector. I was so impressed that a forced
convection device could look so slim and functional I
just had to talk about them and so they have become part
of our presentation. If anyone knows the manufacturer
please let us know.
Figure 8: We were very successful in our
rep business and one of the thoroughbreds we had was
Myson which included fan/coils, fan/convectors, panel
radiators (above) and towel warmers (below). These
are the traditional European method for space heating
and you'll find them everywhere you go when visiting the
UK, Sweden, Denmark, Germany, Noraway, Italy etc...
Figure 9: There is something elegant
about towel warmers and heated benches - how could you
not want one or both of these beautiful devices in your
home or offices. We've just finished a new design
project in Calgary where we have specified three of
these wonderful heating elements.
Figure 10: Our industry colleagues
from Uponor are mastering the art of connecting heat
terminal units to boiler and chiller plants by running
pre-insulated flexible PEX pipe in ground and even above
in truss spaces. If you can go low it makes more sense
from a labour and material cost as well as job site
safety. It's fast and effective and you should be doing
this on all your residential or commercial projects.
Figure 11: After all these years
this is still one of my favourite residential mechanical
rooms! It's clean and professionally assembled using
manufactured control appliances. Not all homes are this
big but even the more conservative project can still
have a great looking mechanical room that won't destroy
the value of the home when it comes time to sell the
Figure 12: Here's my good friend Tim
Doran from Taco-HVAC. Tim gave me a tour of the TACO
HVAC Innovation & Development Center which included a
tour to the heating and cooling plant. Without a doubt
one of the nicest commercial boiler rooms I've been in.
They walk the talk at Taco as do many other manufactures
I've worked with...they use solar, evaporative cooling,
radiant cooling and heating, chilled beams, panel
radiators - you name it- they use it; and use the new
facility to demonstrate the fundamentals in equipment
applications. Photo Courtesy of Taco Inc.
Figure 13: Ok back to the
engineering side of systems. In our heat terminal unit
lecture we'll introduce the math behind the equipment
including this fundamental formula in heat transfer.
Figure 14: I don't know how many
jobs I've been to where the flow in a heat exchanger was
all bassackward...it matters if the flow is in parallel
or counter flow and we'll demonstrate this with the
log mean temperature calculation.
Figure 15: This summary chart lays
out the control and compensation methods for various
types of heat terminal units. Notice how only the hybrid
systems at the bottom really cover all the basis for
conditioning people and spaces.
Figure 16: Here are some typical
ranges for heating and cooling for different heat
terminal units. This is not trivial stuff as low
temperature devices enable high performance in heating
systems and high temperature devices enable high
performance in cooling systems. See our discussion on
the importance of using aluminum
heat transfer plates in radiant systems.
Figure 17: Ohhh this not be good
(grin)...see how Denmark and Finland have earned high
effectiveness coefficients by their choice of heat
terminal units and operating temperatures and
differential temperatures? Historically our culture has
been one of small and low cost heat terminal units but
use very high temperatures to achieve heating. This has
destroyed our ability to enable maximum efficiency from
our boiler plants and essentially eliminates any
opportunity to connect to community based systems using
low temperature fluids.
Figures 18: All heat terminal units do not
behave the same way - they in fact have different
personalities based on their responsiveness, i.e. low
mass to high mass and forced convection vs. natural
convection. Because they have different personalities
they need to have
different controls and we spend significant time
discussing this in class. Credit to TA's retired
Professor Robert Petitjean for passing on his passion
for pressure. We used to represent TA as well back in
the day and still specify their products when we can.
Figure 19: I'm always keeping my
eyes out for equipment that is designed to fit into
developing trends in HVAC and this product by Daikin is
one such device. It's an HRV with a cooling coil which
fits my needs for doing radiant cooling with
dedicated outdoor air system (DOAS). The ventilation
component takes care of the air exchange and the coil
takes care of the dehumidification.
Figure 20: Where hydropower, wind
or PV is in play - we'll specify heat pumps with low
temperature radiant heating and high temperature radiant
cooling to really enable
maximum exergy efficiency.
Figure 21: Likewise we'll
use solar for those clients with demonstrated
economics or if they just want to lead the way in
sustainability - for some clients it just feels good to
do good things.
Solar will do that for you.
Figure 21: Here it is - one of the
key messages in outcomes from mixing buildings with
mechanical systems. Where do you want to be?
So there you have it, a few sample slides
from our heat terminal lecturer...just a hors d'oeu·vre
from our library of over 2100 slides addressing a small
but important element of integrated design and radiant
based HVAC systems. In the
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.