[Equest-users] Adding Insulation toexistingbuilding(UNCLASSIFIED)

Fri Sep 9 14:28:56 PDT 2011

Your analogy regarding optimizing the orientation of a "massive internal
load" in a speedo on the beach sounds like the start of a great pickup
line!  Ladies of the mailing list - what say you???

...Having duly noted that important point: Mr. "heat a building with a
match" is on shaky ground.  That feat would be awesome in a space
station where it's absolute-zero outside all year (IAQ issues aside),
but as you're noting: we live and pay energy bills in a world where we
have to consider the cooling months as well. 

>From my toe-to-toe engineering matchups however, I'd say your real
challenge is to redirect the discussion and get him to agree on the
isolated issue-at-hand.  It's a lot easier to arrive at a targeted
consensus if you avoid unnecessarily "proving" someone wrong.  If you
can keep your cool at the table and respectfully disagree and make your
case while your compadre is flustered/defensive and unable/unwilling to
acknowledge to your well-stated points, then you've already won the
argument for anyone else at the table paying attention.

I would (respectfully) disagree at "the building shouldn't depend on the
skin to remove heat" as this is misleading at best.  Nobody is trying to
describe an envelope as a heatpump.  It's tempting to point out an
envelope can be an extremely efficient "mover of heat" at times, but
that just complicates the discussion with a disagreeable person, so I
wouldn't go there.

I would offer a modified statement to illustrate the point you need to
convey:  "the building envelope should not make the heating OR cooling
systems work too hard."  Anyone disagreeing on this fundamental point
hasn't taken the time to play with an energy model and more importantly
isn't using logic.  

If necessary, you could make the point explicitly clear to everyone at
the table with a parametric study gradually changing only the envelope
constructions incrementally for your project - one of the graphical
output reports shows end-use consumptions for each run side by side if
I'm not mistaken and would work nicely.  You'll see a curve take shape
for the total consumption showing positive, diminishing, then negative
returns as you increase the R-value.  From this, you can illustrate the
point that every building has a unique "sweet spot" that no minimum
insulation requirement can readily define.  Overly-high minimum values
can definitely force you into "super insulation" (I'm starting to like
that term!), which sounds great until you realize it's costing you.

I would follow the trend your model is reporting to you regarding
economizer OA as a cooling means:  Economizers will at best only take
the edge off "super-insulation" problems, and won't address the
fundamental dilemma of providing a means of cooling when the OA is too
hot for the task.  

A perspective to share for everyone following along:  "CERL" is about as
much as should be said regarding the fellow we're discussing publicly on
the list here (and may already be too much).  Anonymity affords us the
ability to criticize, correct and openly discuss issues without harming
anyone's credibility or good name.  Just because I find a LEED
reviewer's interpretation disagreeable/wrong doesn't mean I really want
that person to end up losing his/her job, for example.  I think it's
appropriate to stick with "Mr. match-furnace" or similar until he should
decide to join the conversation of his own free will =).

~Nick

NICK CATON, P.E.
SENIOR ENGINEER

Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036
fax 913.345.0617
www.smithboucher.com 

-----Original Message-----
From: Eurek, John S NWO [mailto:John.S.Eurek at usace.army.mil] 
Sent: Friday, September 09, 2011 2:29 PM
To: Nick Caton; David Eldridge; equest-users at lists.onebuilding.org
Subject: RE: [Equest-users] Adding Insulation
toexistingbuilding(UNCLASSIFIED)

Classification: UNCLASSIFIED
Caveats: NONE

Today I received an e-mail with recommendations from the Construction
Engineering Research Laboratory (CERL) and in the recommendations was an
R-50
roof (super insulation).

The recommendations were from the building I ran energy models for and
my
results showed that too much insulation increases energy use.  I hit
'reply
all' to the e-mail and told everyone that I disagree with their research
and
explained what my models showed.  I received a call from a person from
CERL,
he was a little defensive.  We agreed with everything but the super
insulation.

I know this will come up in a future meeting and before I go toe-to-toe
with
him and tell the guy he is wrong, I want to make sure I am right.

One of his quotes was "We want the insulation so good that you can heat
the
room with a single match."  I repeatedly told him that it isn't the
heating,
it is the cooling.  He responded with, "the building shouldn't depend on
the
skin to remove heat". I agreed using the skin for cooling isn't the best
method, but it is what happens.

I would agree with him that super insulation would be great IF the
system has
the ability to bring in a lot of outside air.  The outside air will be
'free
cooling' minus the fan energy.  The large amount of outside air in
essence
allows you to artificially make the R value zero (just like opening the
windows)  (*snicker to myself - it is fan assisted natural ventilation*)

Will the ability to draw in outside air solve the problem of increased
cooling load for a super insulated building?

Also, to those who are still reading - A part of the energy modeler's
job is
to understand what is happening then explaining it to others. (Even
architects) 
The analogies below all involve this building with massive internal
loads.
The architect insisted that you can reduce energy use by optimizing the
orientation.  I ran the model, it only made a 0.05% difference.

-I told him "It is like trying to get better gas mileage by turning down
the
radio in your car.  The skin load is tiny compared to the servers,
lights and
computer loads."
-Later I told somebody "It is like trying to make a bull-doze
aerodynamic,
this building is a work horse.  If it were an empty house I would agree
rotation matters more."
-And "With this much insulation, the orientation doesn't matter as much.
If
you on the beach in a speedo it matters. If you are in a parka covered
head
to toe, not so much."

John Eurek PE, LEED AP
Mechanical Engineer,
US Army Corps of Engineers
Omaha District CENWO-ED-DA
1616 Capitol Avenue
Omaha, NE 68102
Phone: (402) 995-2134
email: john.s.eurek at usace.army.mil

-----Original Message-----
From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Nick
Caton
Sent: Thursday, September 08, 2011 2:52 PM
To: David Eldridge; equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Adding Insulation
toexistingbuilding(UNCLASSIFIED)

David,

Remind me never to ask you how a thermos works ^_^.

John,

I wrote most of this yesterday and David beat me to the punch... I'm
echoing much of the same from his response but maybe it'll help as
well??

...

Economizers work just as you describe, and are great energy savers when
the OA temps are conducive to comfort... (moving air generally takes
less energy than moving heat + air) 

But sometimes it's 110F+ at your RTU in the dead heat of the summer...
In our local climate and I'm sure many others, the brunt of the cooling
season has OA temps well above what we want to supply to achieve comfort
inside.  Economizer function isn't terribly helpful in this situation.
With too much insulation, you still run into the same fundamental
problem of "too much heat inside," with no options but to reject the
heat using your cooling equipment outside, even if you do have an
economizer.

Your assertion holds true, that super-insulation can be a non-issue when
you have an economizer, but only for specific times in the year when the
outside conditions are cooperating.  Where having an economizer (or not)
may have a dampening effect on the relative impact/problem of
"super-insulating" on an annual basis, it could only remove the issue
for the brunt of the cooling season in a specific sort of cool,
temperate climate.

Even in such a climate, blasting tons of extra air into the building to
"get around" someone's decision to over-insulate the envelope doesn't
seem ideal... every building should have an envelope construction where
"enough is enough."

There is an easy answer to your office's water query: "it depends."
(haha, I'll be here all night!)  

There unfortunately isn't a blanket rule here because the answer does
depends on efficiency of the pumps (or fans), which itself is dependent
on the piping (or duct) static being overcome (variability of that comes
into play for some systems), and the efficiency of the cooling equipment
as well - be it a chiller plant or rooftop DX refrigeration...
everything balances out and playing with different supply temps/flow
rates will return a unique answer for every project if you take the time
to play with it.

... 

As David concludes, this is indeed why modelers are ultimately such
popular characters =)!

~Nick

NICK CATON, P.E.
SENIOR ENGINEER

Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036
fax 913.345.0617
www.smithboucher.com

NICK CATON, P.E.
SENIOR ENGINEER

Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036
fax 913.345.0617
www.smithboucher.com 

-----Original Message-----
From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of David
Eldridge
Sent: Wednesday, September 07, 2011 3:50 PM
To: equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Adding Insulation to
existingbuilding(UNCLASSIFIED)

Nick, my analogy when I talk about coffee thermoses is a metal building
with internal loads and varying insulation levels.

Anyway - back to the original poster, this phenomenon could more often
be
true where generally it is cooler outside than inside for much of the
year.

To reply to John E.'s subsequent post -- there likely will still be some
hours where it is cooler outside than inside (and the insulation is now
a
detriment) even if there is an  economizer.  Even while the air system
is
providing cooling (whether compressor-based or economizer) the walls may
still be conducting energy -- they don't stop based on the HVAC system
status.

Certainly the availability of an economizer can mitigate this problem,
but
might not make it go away completely.

But that's why we have energy models -- insulation that looks great at
both design days will still have some hours in the middle where it might
make energy use higher -- run a model and find out what the net is.
(Unless the building is on Mercury...then always add as much as
possible.)

David

David S. Eldridge, Jr., P.E., LEED AP BD+C, BEMP, BEAP, HBDP
Grumman/Butkus Associates

-----Original Message-----
From: equest-users-bounces at lists.onebuilding.org
[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Nick
Caton
Sent: Wednesday, September 07, 2011 3:00 PM
To: Eurek, John S NWO; mikef at facilitymgt.com;
equest-users at lists.onebuilding.org
Subject: Re: [Equest-users] Adding Insulation to existing
building(UNCLASSIFIED)

Agreeing with John per usual...

Any building with internal loads will have some break-point where adding
more insulation to the envelope will be detrimental to annual energy
consumption.  It's a bigger deal whenever your internals are relatively
high.  The behavior you're describing is fundamentally sound.

A good thermos keeps my coffee hot longer (great in the wintertime), but
it's not the ideal container when my coffee is scalding-hot and I want
the contents to cool down.

I've yet to settle on a favorite analogy myself... this just comes to
mind because I need to make a new pot here at work...

NICK CATON, P.E.
SENIOR ENGINEER

Smith & Boucher Engineers
25501 west valley parkway, suite 200
olathe, ks 66061
direct 913.344.0036
fax 913.345.0617
www.smithboucher.com
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Classification: UNCLASSIFIED
Caveats: NONE