Try This at Home! Please!

This post was inspired by a question from Alicia Breen, one of
the students in a monthly retrocommissioning/ongoing commissioning
class that I teach at the Pacific
Energy Center
with
Ryan Stroupe
(page down a bit after you hit the link and
you’ll find him) and Tony Pierce
(ditto once you follow the link to Tony).  The class is a one
day a month plus homework commitment for 12 months on the part of
the students, so its not a causal undertaking. Over its course, the
students get lecture and hands on experience with commissioning
techniques using the systems at the PEC, culminating in a
functional test targeted at addressing an issue identified earlier
in the year in the facility. In addition, the students work on a
project in their home facility (where they work, their house, or a
facility requiring some sort of commissioning attention and
volunteered by someone like Virginia Waik,  the Utilities
Marketing Engineer for the City of Palo Alto
,who has a passion for commissioning, efficiency and generally
making the world a better place that few could
match).  

In any case, for the December session, the homework assignment
was to perform some sort of test using some combination of data
loggers, trend analysis and discrete measurements on the student’s
project system or, lacking that on some other system, like their
house. Much to her dismay, Alicia found that she could not get
sufficient access to her project system during December and January
to allow her to do the testing she had hoped to do. So she was
considering testing something in her house and e-mailed me to ask
for suggestions and council.

I’ve actually learned quite a bit by working on my house,
including how to run conduit, how to run pipe, how to frame, how to
run ductwork, how to landscape, etc. I might add that I’ve also
learned a lot  about how
not  to do those things. These lessons have
been really valuable for me because while, for instance, my little
half inch conduit run is pretty piddley compared to what the “big
boys” do on commercial and industrial projects, running it gave me
a lot of insights into and an appreciation of the challenges they
face, the skills they have, and the fundamental mechanics behind
the task. These lessons not only made me a better designer and
engineer, they also gave me some insight into some one elses world.
These insights are invaluable in the field because while in theory,
commissioning is, at its heart about performance and integrating
machinery, my experinence has been that about half of that hinges
on integrating the team that is putting the project together and
operating it. If the team isn’t integrated and on the same page,
then its a lot harder to get the machines to that point. And, the
reality is that, in most cases, we are all just people trying to do
a good job, pay the bills, have some time with the ones we love.
The more I know about the buildings I work on and the folks that
build and operate them and their skills (and visa versa) the better
off we will all be.

So, as I typed back to Alicia I realized that what I was
suggesting to her might also be worthy of suggestion to a broader
audience. So here I am and there you are (I hope). In general
terms, what I am suggesting in the following paragraphs is that you
use the place where you live as a little laboratory to gain insight
into the things you do at work in this industry. Granted, its on a
smaller scale and probably a much less complex scale. But the
reality is that the underlying principles are the same and, as Jay
Santos would say “nature doesn’t lie”. I’ve found that learning
things from a “discussion” with nature on a smaller more manageable
scale (represented in the context of this blog post by your house)
is a lot better than having the same discussion in a high rise or
industrial complex. In that context, here are some things that you
might investigate.

Ask your self if there is any problem with your home that has
bothered you. For instance, is there a room that is uncomfortable
relative to the others? Is the HVAC system noisy when it runs? Do
you wish that your utility bills were lower and is that a realistic
wish? As a side note, I suspect that everyone wishes that their
utility bills were lower, But, for instance, my worst case heating
bill is about $50 for gas. That’s probably because Kathy (my bride)
and I have a small house, reasonably tight and well insulated in a
mild climate with a high efficiency gas furnace; probably not much
that I can do to meaningfully reduce the bill. That doesn’t mean
there aren’t meaningful things I can do to improve the way I use
gas, which is a non-renewable resource that generates atmospheric
carbon when I burn it. But, given the modest cost (currently) to
heat my home, the perspective driving the desire to improve things
will need to be more holistic rather than economic – a lesson I
think for our current bottom line driven society. Anyway, the point
of these questions is to find out if there is something you want to
target a test at. Probably 50% or more of the tests performed by
commissioning providers in the field are targeted at solving a
specific problem or verifying a specific level of performance. But,
that doesn’t mean you can’t learn something if you
don’t have a problem to target with your test. You can do an
information gathering test and find out exactly how your house
performs. Here are some ideas that come to mind.

Deploy a data logger outside that tracks relative
humidity (RH) and temperature and then deploy several loggers
inside tracking the same thing along with maybe some indication of
occupancy like light level or the operation of an electric light,
and maybe one that tracks furnace operation. Then plot concurrent
data to see how the environment inside your house responds to
changes in the ambient environment and the use patterns. For
instance, what happens to the RH inside when you take a shower? At
night, if your furnace has night set-back, how fast does the
temperature in the house drop off relative to how fast the
temperature outside drops off. How about RH? How does RH compare to
specific humidity or dew point which is a more absolute indication
of moisture level? (Some data loggers will calculate dewpoint an
specific humidity basedo on the parameters they measure.  But
if not, you can figure it out from a psych chart). How does
absolute humidity inside and outside compare and track?

Deploy a current or kW logger on your power panel and on
some critical (large) loads like the your dishwasher or your washer
and dryer or your water heater (if it’s electric) and plot
concurrent data to see how much of an impact on total load each
appliance has. Add more loggers to other circuits serving light
loads and plug loads to see how you use energy in your house. Only
do this if you feel comfortable putting CTs on your circuits or if
you know someone who is an electrician or who is comfortable doling
that for you if you aren’t.  (Electricity,
even at the voltages we use in our homes can be dangerous
if
you don’t know what you are doing or aren’t comfortable working
around it.  Never do anything with electrical wiring
that you are not comfortable doing and/or have not been properly
trained to do.)

Put a logger on your furnace to measure differential
temperature and pick up fan operation. Or deploy or add another one
to monitor filter pressure drop. Deploy another outside to track
ambient conditions or download the data from the web using one of
the techniques/sites discussed in the
Functional Testing Guide
.  Use a rotating
vane anemometer
to traverse your return grilles and get an idea
of air flow. Then, simply log the operating of the system and see
what it tells you. For instance, how does the actual capacity of
the furnace compare to the rated capacity? How does the cycling
time vary with changes in outdoor temperature? If you have a night
set back thermostat, how does that impact the operation of the
system vs. the way it operates once the house is warmed up or, at
night once the house has cooled off to the set-back temperature?
How long does it take your filter to load up? (Generally, filters
should be changed
on pressure drop
, not appearance
or time
).

Use the rotating vane anemometer to traverse your return
grills and get a feel for total system flow. Then traverse your
supply grills and see how the flow is distributed. Is it fairly
uniform on a cfm per square foot basis, or are their areas with a
lot of air and areas with less? If the distribution is not uniform,
is that because of the loads in the areas served? Or does your
system need balanced? (Maybe there is a reason that one area is
always hot or cold!)

If you have an electric water heater log its power
consumption and then use that data to compare what would happen if
you heated your water using one of the
heat pump based technologies
that’s out there or using a
conventional gas water heater or using one of the high
efficiencyinstantaneous
type heaters
. Look at both the source and
site energy implications and the atmospheric carbon
implications
.

Some of you may be thinking “that’s all well and good, but what
if I don’t have a data logger?” If you live in California in one of
the public utility service districts, you are in luck. You can
borrow a logger from the Pacific Energy Center’s
tool lending library
. This is (as us 60’s generation folks
would say) a “free to the people” resource that is available to you
as a utility customer. Many of the private utilities in California
and other states offer a similar service. Another option is to
simply buy a logger. For under
$100
, you can be off and running. For about $300, you can be
logging just about anything. I wouldn’t be surprised if you
discovered you didn’t need the new DVR if you bought a logger
instead because you will be having so much fun learning things
about your house or the building you are working on (and making the
world a little bit better at the same time) that you won’t have
time for a lot of TV. (I also realized that your kids and
significant other might have a different perspective on this. The
trick there is to make the first problem you solve with your new
tool – a.k.a. toy – be something that has been driving your
significant other crazy and to let the kids use your new tool for
their science project; they’ll probably blow away the
competition.)

So, bottom line, do a science experiment on your home. You may
be surprised by what you learn. And I’ll guarantee that what you
learn will make you a better technical person in the buildings
industry, no matter what your role is.

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