In the equation in section 6.2.2.1, "Az" is defined as "zone floor area: the net occupiable floor area of the zone"<br><br>and "occupiable space: an enclosed space intended for human activities, excluding those spaces intended primarily for other purposes, such as storage rooms and equipment rooms, that are only occupied occasionally and for short periods of time."<br>
<br>I think it is pretty clear that storage rooms that are rarely occupied don't need to be provided with ventilation air. Yes, if the room is storing something that emits or smells, I would hope that the designer would use common sense and provide ventilation air, but if a space is only occupied for very short periods of time, and not very often, it doesn't make sense to go to the expense of installing a ventilation system, and spend $$ on conditioning the ventilation air.<br>
<br>I am still not sure about corridors. These are spaces that people commonly go through, but actual average occupancy is very low. In addition, the ventilation requirements for corridors is low. For a building that have separate heating and cooling equipment in each zone, and no central air system, does it really make sense to pipe 30 cfm of ventilation air to the corridor? What about naturally ventilated buildings? Often the corridor doesn't meet the requirements for natural venilation as it is in the core of the building. Are you going to add an entire ventilation system just for the corridor?<br>
<br>--<br>Karen<br><br><br><br><div class="gmail_quote">On Thu, Nov 12, 2009 at 4:41 PM, Matutinovic, Luka <span dir="ltr"><<a href="mailto:LMatutinovic@halsall.com">LMatutinovic@halsall.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-US">
<div>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;">Nick,</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;"> </span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;">I agree that both a per-person and per-area rate must be calculated
to determine the total OA. I have two comments though:</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;"> </span></p>
<p><span style="font-size: 10pt; color: blue;"><span>1.<span style="font-family: "Times New Roman"; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">
</span></span></span><span style="font-size: 10pt; color: blue;">In many jurisdictions, ASHRAE 62.1 is not suggested practice,
rather a code that must be met. For example, all buildings built in
Ontario must be designed in accordance with 62.1.</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;"> </span></p>
<p><span style="font-size: 10pt; color: blue;"><span>2.<span style="font-family: "Times New Roman"; font-style: normal; font-variant: normal; font-weight: normal; font-size: 7pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">
</span></span></span><span style="font-size: 10pt; color: blue;">I don’t think you could ever effectively argue that there are
any unoccupied spaces in a building, other than say mechanical shafts (I clearly
just contradicted myself…). Although a storage room is not regularly
occupied, somebody will eventually have to store something in it and at some
point retrieve it. </span></p>
<p><span style="font-size: 10pt; color: blue;"> </span></p>
<p><span style="font-size: 10pt; color: blue;">Regardless though, Pz in equation 6.2.2.1 applies only to the
per-person rate, which in the case of storage rooms and corridors is zero
anyway, so the zone outdoor airflow Vbz reduces to just the per-area rate x
area. Therefore, I think the per-area rate must always be supplied to all
spaces in the building during regularly occupied hours. At night, the
ventilation system in the office building can be turned off, but during normal
office hours it should supply the total OA, which includes OA for non-regularly
occupied areas. For multi-zone systems the total OA is usually lower than
the sum of all Vbz, to account for occupant diversity and other system
parameters. </span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;"> </span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;">I think in reality, not all spaces are directly provided with ducted
ventilation air, and transfer air is often introduced via grilles in the doorway.
Granted, one could question the effectiveness of that delivery given the lack
of exhaust fans to induce the air into the room as would be the case in
washrooms. Nonetheless, I’ve seen it done before. </span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;"> </span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;">Cheers,</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;"> </span></p>
<p class="MsoNormal"><b><span style="font-size: 9pt; color: blue;">Luka Matutinovic, </span></b><span style="font-size: 9pt; color: blue;"><a href="http://B.A.Sc" target="_blank">B.A.Sc</a>., LEED<sup>®</sup> AP</span><span style="color: blue;"></span></p>
<p class="MsoNormal"><i><span style="font-size: 7.5pt; color: blue;">Green Building Consultant</span></i></p>
<p class="MsoNormal"><i><span style="font-size: 6pt; color: blue;"> </span></i><i><span style="font-size: 6pt; color: blue;"><br>
</span></i><span style="font-size: 7.5pt; color: blue;">T. 416.644.0649</span><span style="color: blue;"></span></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: blue;">F. 416.487.9766 <br>
Toll Free 1.888.425.7255<br>
<a href="http://www.halsall.com" target="_blank">www.halsall.com</a> <br>
</span><span style="font-size: 6pt; color: blue;"><br>
</span><b><span style="font-size: 9pt; color: blue;">HALSALL ASSOCIATES LTD. <br>
</span></b><span style="font-size: 7pt; color: blue;">Toronto Richmond Hill Ottawa Sudbury <br>
Burlington Calgary Vancouver Dubai <br>
</span><span style="color: blue;"><br>
</span><b><span style="font-size: 7.5pt; color: blue;">‘50 Best Workplaces in Canada’ </span></b><b><span style="font-size: 7.5pt; color: blue;"><br>
</span></b><i><span style="font-size: 7.5pt; color: blue;">2009 Globe and Mail</span></i><i><span style="font-size: 7.5pt; color: blue;"><br>
</span></i><span style="font-size: 18pt; font-family: Webdings; color: green;">P</span><b><span style="color: black;"> </span></b><b><span style="font-size: 7.5pt; color: green;">Please consider the environment before
printing this e-mail</span></b><span style="font-size: 10pt; color: blue;"></span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;"> </span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: blue;"> </span></p>
<div>
<div style="border-style: solid none none; border-color: rgb(181, 196, 223) -moz-use-text-color -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;">
<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>] <b>On Behalf Of </b>Nick Caton<br>
<b>Sent:</b> Thursday, November 12, 2009 4:11 PM<br>
<b>To:</b> Karen Walkerman<div class="im"><br>
<b>Cc:</b> <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
</div><div><div></div><div class="h5"><b>Subject:</b> Re: [Bldg-sim] ASHRAE 62.1 unoccupied space minimum
outdoorairsupply</div></div></span></p>
</div>
</div><div><div></div><div class="h5">
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Note that Table 6-1 has “—“ under the
CFM/person values for (“General”) corridors, storage spaces,
electrical rooms and similar spaces. I consider this ASHRAE’s
indirect guidance on spaces you can consider “typically unoccupied”
(Pz = 0) for the purposes of determining the minimum OA rate.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">~Nick</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"><img src="cid:image001.jpg@01CA63B3.ECC093E0" alt="cid:489575314@22072009-0ABB" width="119" height="37"></span><b><span style="font-size: 11pt; font-family: "Stylus BT"; color: rgb(45, 77, 94);"></span></b></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; font-family: "Stylus BT"; color: rgb(45, 77, 94);"> </span></b></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; font-family: "Stylus BT"; color: rgb(45, 77, 94);">NICK CATON, E.I.T.</span></b><b><span style="font-family: "Stylus BT"; color: rgb(45, 77, 94);"></span></b></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: rgb(204, 153, 0);">PROJECT ENGINEER</span><span style="font-size: 7.5pt; color: rgb(204, 153, 0);"></span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">25501 west valley parkway</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">olathe ks 66061</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">direct 913 344.0036</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">fax 913 345.0617</span></p>
<p class="MsoNormal"><i><span style="font-size: 10pt; color: rgb(45, 77, 94);">Check out our new web-site @ </span></i><span style="font-size: 11pt; color: rgb(31, 73, 125);"><a href="http://www.smithboucher.com" title="blocked::www.smithboucher.com" target="_blank"><span style="font-size: 10pt;">www.smithboucher.com</span></a></span><u><span style="font-size: 10pt; color: blue;"> </span></u><span style="font-size: 11pt; color: rgb(31, 73, 125);"></span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<div style="border-style: solid none none; border-color: rgb(181, 196, 223) -moz-use-text-color -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> Karen Walkerman
[mailto:<a href="mailto:kwalkerman@gmail.com" target="_blank">kwalkerman@gmail.com</a>] <br>
<b>Sent:</b> Thursday, November 12, 2009 2:34 PM<br>
<b>To:</b> Nick Caton<br>
<b>Cc:</b> Brahme, Rohini UTRC; <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
<b>Subject:</b> Re: [Bldg-sim] ASHRAE 62.1 unoccupied space minimum
outdoorairsupply</span></p>
</div>
<p class="MsoNormal"> </p>
<p class="MsoNormal" style="margin-bottom: 12pt;">Ok, this makes more
sense. What about corridors that have only transient and very low
occupancy rates? Can this also be classified as unoccupied?<br>
<br>
Thanks,<br>
<br>
--<br>
Karen</p>
<div>
<p class="MsoNormal">On Thu, Nov 12, 2009 at 2:07 PM, Nick Caton <<a href="mailto:ncaton@smithboucher.com" target="_blank">ncaton@smithboucher.com</a>> wrote:</p>
<div>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">I may be wrong, but it appears a number
of people aren’t examining the equation in 6.2.2.1 as I’m
suggesting. If you’ll check that out I’m certain you’ll
find this is a much simpler question/answer than it’s being made out to
be.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><u><span style="font-size: 11pt; color: rgb(31, 73, 125);">Both</span></u><span style="font-size: 11pt; color: rgb(31, 73, 125);"> sets of figures provided in Table 6-1 (OA/person and OA/SF)
are used to determine the design minimum OA rate, using 6.2.2.1’s
equation. Occupancy has no effect on the OA/SF requirement, and likewise
zonal area has no effect on the OA/person requirement. Additionally, the
occupancy figure used is the <u>maximum</u> occupancy of that zone.
Quoting <a href="http://6.2.2.1" target="_blank">6.2.2.1</a>:
“Pz = zone population: the largest number of people expected to occupy
the zone during typical usage…” It is not the hourly
percentage occupancy and is not zero unless the space is never normally
occupied (as with a storage room like Karen suggested).</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">The design minimum OA rate is only
applicable when the ventilation system is operating. Unless I’m
missing something major, the ventilation system is not required by ASHRAE 62.1
to operate 24 hours per day (again, refer to Section 5.4, which
I’ve copied entirely below).</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">I’ll try to break down the current
questions/statements on the table:</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(0, 51, 0);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(0, 51, 0);">The reason I had the question was because
I think OA/sqft technically should not be dependent on occupancy…</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">That’s a fair judgement a designer
is allowed to make. The 62.1 Standard is just that – not a code,
but a set of suggestions provided by some of those best qualified to provide
them. To play the devil’s advocate, the counter-argument is that
Occupancy cannot be ignored by an energy-conscious ventilation system designer.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(0, 51, 0);">…If that was the case, it would
suffice to just increase the OA/sqft and have only one number to take care of.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Someone doing that would be ignoring the
equation Table 6-1 was built around (re: 6.2.2.1). I’d agree that
would be a misinterpretation of the standard.</span></p>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(0, 51, 0);">What I am not sure of is whether OA/sqft
is used only during the typical occupied hours irrespective of whether it is
actually occupied or not or is it used throughtout the day/weekend/vacation
etc.</span></p>
</div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">OA/SF is always used alongside OA/person
to determine the “breathing zone outdoor airflow.” (Which
I’ve been calling the design minimum OA rate). The question of when
these ventilation rates apply is tied to when the zone is occupied. To
restate my position (Again Ref: Section 5.4): ASHRAE 62.1 does not
require that ventilation systems operate during unoccupied times.</span></p>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(0, 51, 0);">What do the hvac designers specify for
the control of OA?</span></p>
</div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Not sure whether a concise answer can be
provided to this broad question… OA ventilation <u>can</u> be controlled
by any combination of scheduling/occupancy sensing/timer
control/temperature/humidity/VOC, CO2, CO or other air quality sensors…
all depending on the project budget, climate, and type of system being
designed. If this question had a simple answer, then we wouldn’t
need HVAC designers =).</span></p>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal">what
happens when you have a space that is almost NEVER occupied, but has a cfm/sf
requirement - like a storage room with a requirement of 0.12 cfm/sf. </p>
</div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">See my answer above.</span></p>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal">So
do you need this ventilation rate only when the building is occupied, only when
the space is occupied, or all the time?</p>
</div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Strictly speaking, only when the zone
(space) is occupied. If you have a one-zone system that doesn’t
distinguish between occupancy rates, then whenever the building is occupied.</span></p>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal">If
you only need the ventilation when the space is occupied, and it is almost
never occupied, why install the ventilation in the first place?</p>
</div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">This is a broad-scope question, so
I’ll add another quote under Section 1, entitled “PURPOSE:”</span></p>
<p class="MsoNormal" style="margin-left: 0.5in;"><b><span style="font-size: 11pt; color: rgb(31, 73, 125);">“1.1</span></b><span style="font-size: 11pt; color: rgb(31, 73, 125);">
The purpose of this standard is to specify minimum ventilation rates and other
measures intended to provide indoor air quality that is acceptable to human
occupants ant that minimizes adverse health effects.”</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">If a space is never occupied, then
ASHRAE doesn’t care about air quality. If a space is “almost
never occupied,” then they do. To continue your example, if you
have a storage warehouse with no ventilation installed, and it’s almost
never occupied, someone might eventually store something in that space that
without ventilation would eventually cause a health hazard to the next occupant
entering the space. In my college years, this was a commonly observed
effect caused on a small scale by my roommates forgetting food in the microwave
=).</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">~Nick</span></p>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">~Nick</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"><img src="cid:image001.jpg@01CA63B3.ECC093E0" alt="cid:489575314@22072009-0ABB" width="119" border="0" height="37"></span></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; color: rgb(45, 77, 94);"> </span></b></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; color: rgb(45, 77, 94);">NICK CATON, E.I.T.</span></b></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: rgb(204, 153, 0);">PROJECT ENGINEER</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">25501 west valley parkway</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">olathe ks 66061</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">direct 913 344.0036</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">fax 913 345.0617</span></p>
<p class="MsoNormal"><i><span style="font-size: 10pt; color: rgb(45, 77, 94);">Check out our new web-site @ </span></i><span style="font-size: 11pt; color: rgb(31, 73, 125);"><a href="http://www.smithboucher.com" title="blocked::www.smithboucher.com" target="_blank"><span style="font-size: 10pt;">www.smithboucher.com</span></a></span><u><span style="font-size: 10pt; color: blue;"> </span></u></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
</div>
<div style="border-style: solid none none; border-color: -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> Karen
Walkerman [mailto:<a href="mailto:kwalkerman@gmail.com" target="_blank">kwalkerman@gmail.com</a>]
<br>
<b>Sent:</b> Thursday, November 12, 2009 12:28 PM<br>
<b>To:</b> Brahme, Rohini UTRC<br>
<b>Cc:</b> Nick Caton; <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a></span></p>
<div>
<div>
<p class="MsoNormal"><span style="font-size: 10pt;"><br>
<b>Subject:</b> Re: [Bldg-sim] ASHRAE 62.1 unoccupied space minimum
outdoorairsupply</span></p>
</div>
</div>
</div>
<div>
<div>
<p class="MsoNormal"> </p>
<p class="MsoNormal" style="margin-bottom: 12pt;">Ok, so here's
a question - what happens when you have a space that is almost NEVER occupied,
but has a cfm/sf requirement - like a storage room with a requirement of 0.12
cfm/sf. This is a pretty high outdoor airflow, especially if you're just
storing old files.<br>
<br>
So do you need this ventilation rate only when the building is occupied, only
when the space is occupied, or all the time?<br>
<br>
If you only need the ventilation when the space is occupied, and it is almost
never occupied, why install the ventilation in the first place?<br>
<br>
<br>
--<br>
Karen</p>
<div>
<p class="MsoNormal">On
Thu, Nov 12, 2009 at 1:11 PM, Brahme, Rohini UTRC <<a href="mailto:BrahmeR@utrc.utc.com" target="_blank">BrahmeR@utrc.utc.com</a>>
wrote:</p>
<div>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(0, 51, 0);">Thanks Nick. The reason I had the
question was because I think OA/sqft technically should not be dependent on
occupancy. If that was the case, it would suffice to just increase the OA/sqft
and have only one number to take care of. What I am not sure of is whether
OA/sqft is used only during the typical occupied hours irrespective of whether
it is actually occupied or not or is it used throughtout the
day/weekend/vacation etc. What do the hvac designers specify for the control of
OA?</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(0, 51, 0);">-rohini</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(0, 51, 0);"> </span></p>
<div>
<div style="border-style: solid none none; border-color: -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> Nick
Caton [mailto:<a href="mailto:ncaton@smithboucher.com" target="_blank">ncaton@smithboucher.com</a>]
<br>
<b>Sent:</b> Thursday, November 12, 2009 12:22 PM<br>
<b>To:</b> Brahme, Rohini UTRC; <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
<b>Subject:</b> RE: [Bldg-sim] ASHRAE 62.1 unoccupied space minimum
outdoorairsupply</span></p>
</div>
</div>
<div>
<div>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">I havn’t read the standard in
detail, but isn’t there a requirement of some OA/sqft in addition to
OA/person. </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">You are correct. Refer to the
equation of Section 6.2.2.1 as I referenced below.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">Let’s assume that an office is
assumed normally occupied from 8 am to 6 pm - Then during unoccupied
hours (6.01 pm to 7.59 am) can the OA be zero or should it be OA per sqft?</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">It sounds like you’re asking the
same question I just answered, so I may not be understanding
completely… By Section 5.4 I do not believe an unoccupied space is
required to have any OA supplied. The equation in 6.2.2.1 does include a
component “per square foot,” but that equation is for determining
the design minimum OA rate.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">More tricky, let’s say we have a
occupancy sensor and know that the office is unoccupied from 12.00 pm to 3 pm
(during the regular office times). What is the OA at this time – 0 or
OA/sqft?</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Applying the same logic and the same
section, 5.4, if there are controls that automatically determine a space is occupied
and turn the associated system on to provide the required OA, then
there’s no reason those systems aren’t allowed to turn off while
unoccupied. Short answer for your example: 0.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">I’ll point out, I’m merely
an E.I.T. (with my head in the books) sharing my interpretations, so it may be
worth holding out for a second opinion =).</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">~Nick</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"><img src="cid:image001.jpg@01CA63B3.ECC093E0" alt="cid:489575314@22072009-0ABB" width="119" border="0" height="37"></span></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; color: rgb(45, 77, 94);"> </span></b></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; color: rgb(45, 77, 94);">NICK CATON, E.I.T.</span></b></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: rgb(204, 153, 0);">PROJECT ENGINEER</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">25501 west valley parkway</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">olathe ks 66061</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">direct 913 344.0036</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">fax 913 345.0617</span></p>
<p class="MsoNormal"><i><span style="font-size: 10pt; color: rgb(45, 77, 94);">Check out our new web-site @ </span></i><span style="font-size: 11pt; color: rgb(31, 73, 125);"><a href="http://www.smithboucher.com" title="blocked::www.smithboucher.com" target="_blank"><span style="font-size: 10pt;">www.smithboucher.com</span></a></span><u><span style="font-size: 10pt; color: blue;"> </span></u></p>
</div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<div>
<div style="border-style: solid none none; border-color: -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> <a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>]
<b>On Behalf Of </b>Brahme, Rohini UTRC<br>
<b>Sent:</b> Thursday, November 12, 2009 11:14 AM<br>
<b>To:</b> <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
<b>Subject:</b> Re: [Bldg-sim] ASHRAE 62.1 unoccupied space minimum
outdoorairsupply</span></p>
</div>
</div>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">Since we are on this topic, I had a
question on definition of occupancy.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">I havn’t read the standard in
detail, but isn’t there a requirement of some OA/sqft in addition to
OA/person. </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">Let’s assume that an office is
assumed normally occupied from 8 am to 6 pm - Then during unoccupied
hours (6.01 pm to 7.59 am) can the OA be zero or should it be OA per sqft?</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">More tricky, let’s say we have a
occupancy sensor and know that the office is unoccupied from 12.00 pm to 3 pm
(during the regular office times). What is the OA at this time – 0 or
OA/sqft?</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">Thanks</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);">-rohini</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(153, 51, 102);"> </span></p>
<div>
<div style="border-style: solid none none; border-color: -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> <a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>]
<b>On Behalf Of </b>Nick Caton<br>
<b>Sent:</b> Thursday, November 12, 2009 11:36 AM<br>
<b>To:</b> Guin, Michael; <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
<b>Subject:</b> Re: [Bldg-sim] ASHRAE 62.1 unoccupied space minimum
outdoorairsupply</span></p>
</div>
</div>
<p class="MsoNormal"> </p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">No.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Refer to Section 5.4: </span></p>
<p class="MsoNormal" style="margin-left: 0.5in;"><span style="font-size: 11pt; color: rgb(31, 73, 125);">“Mechanical
ventilation systems shall include controls, manual or automatic, that enable
the fan system to operate whenever <u>the spaces served are occupied</u>.
The system shall be designed to maintain the minimum outdoor airflow as
required by Section 6 <u>under any load condition</u>.” </span></p>
<p class="MsoNormal" style="margin-left: 0.5in;"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">In summary, you must provided the
minimum ventilation rate as prescribed in Chapter 6 only when (A) the space is
occupied and (B) there’s a thermal load condition (or manual control
– see Section 5.4) triggering the operation of the ventilation system.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">Your original question is confusing to
at least a few of us because of stating an office ceases to be a
“zone” at night… It’s a terminology thing, but
62.1 and other standards will become more digestible to you when you recognize
that’s not the case. The clarification we’re making here is
that where a zone occupancy (i.e. “office”) is decided and a constant
over time, something like “occupancy rate” can be variable.</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">I’d like to also point out, based
on your first inquiry, that the equation at 6.2.2.1 uses <u>maximum</u> zone
occupancy to establish the minimum design OA rate, not the hourly occupancy
rate (which may be zero).</span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);">~Nick</span></p>
<p class="MsoNormal" style="margin-left: 0.5in;"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"><img src="cid:image001.jpg@01CA63B3.ECC093E0" alt="cid:489575314@22072009-0ABB" width="119" border="0" height="37"></span></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; color: rgb(45, 77, 94);"> </span></b></p>
<p class="MsoNormal"><b><span style="font-size: 11pt; color: rgb(45, 77, 94);">NICK CATON, E.I.T.</span></b></p>
<p class="MsoNormal"><span style="font-size: 7.5pt; color: rgb(204, 153, 0);">PROJECT ENGINEER</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">25501 west valley parkway</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">olathe ks 66061</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">direct 913 344.0036</span></p>
<p class="MsoNormal"><span style="font-size: 10pt; color: rgb(45, 77, 94);">fax 913 345.0617</span></p>
<p class="MsoNormal"><i><span style="font-size: 10pt; color: rgb(45, 77, 94);">Check out our new web-site @ </span></i><span style="font-size: 11pt; color: rgb(31, 73, 125);"><a href="http://www.smithboucher.com" title="blocked::www.smithboucher.com" target="_blank"><span style="font-size: 10pt;">www.smithboucher.com</span></a></span><u><span style="font-size: 10pt; color: blue;"> </span></u></p>
</div>
<p class="MsoNormal"><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<div>
<div style="border-style: solid none none; border-color: -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p class="MsoNormal"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> <a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>]
<b>On Behalf Of </b>Guin, Michael<br>
<b>Sent:</b> Thursday, November 12, 2009 8:44 AM<br>
<b>To:</b> <a href="mailto:Shawn.Lee@fluor.com" target="_blank">Shawn.Lee@fluor.com</a><br>
<b>Cc:</b> <a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>; <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
<b>Subject:</b> Re: [Bldg-sim] ASHRAE 62.1 unoccupied space minimum outdoor
airsupply</span></p>
</div>
</div>
<p class="MsoNormal"> </p>
<div>
<p class="MsoNormal"><span style="font-size: 10pt;">is there any requirement to provide
minimum outdoor fresh air wihin the office space when it is unoccupied
according to ASHRAE 62.1</span></p>
</div>
<div>
<p class="MsoNormal"> </p>
</div>
<div>
<p class="MsoNormal"><span style="font-size: 10pt;">Do you think it it clear enough? </span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size: 10pt;">Regards</span></p>
</div>
<div>
<p class="MsoNormal"><span style="font-size: 10pt;">Michael</span></p>
</div>
<div class="MsoNormal" style="text-align: center;" align="center">
<hr size="2" width="100%" align="center">
</div>
<p class="MsoNormal" style="margin-bottom: 12pt;"><b><span style="font-size: 10pt;">From:</span></b><span style="font-size: 10pt;"> <a href="mailto:Shawn.Lee@fluor.com" target="_blank">Shawn.Lee@fluor.com</a>
[mailto:<a href="mailto:Shawn.Lee@fluor.com" target="_blank">Shawn.Lee@fluor.com</a>]
<br>
<b>Sent:</b> 12 November 2009 13:58<br>
<b>To:</b> Guin, Michael<br>
<b>Cc:</b> <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a>;
<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a><br>
<b>Subject:</b> Re: [Bldg-sim] ASHRAE 62.1 unoccupied space minimum outdoor air
supply</span></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><br>
<span style="font-size: 10pt;">Michael,</span> <br>
<br>
<span style="font-size: 10pt;">Technically answering your question may not help
you much. You need to make the question clearer and more meaningful.
Tell people what you are trying to do, what is in your mind, and what you
are trying to accomplish. Then this group may help you more on the
target.</span> <br>
<br>
<span style="font-size: 10pt;">Thanks.</span> <br>
<br>
<span style="font-size: 10pt;">Shawn Lee, PhD, PE</span> </p>
<table style="width: 100%;" width="100%" border="0" cellpadding="0">
<tbody><tr>
<td style="padding: 0.75pt;" valign="top"></td>
<td style="padding: 0.75pt;" valign="top">
<p class="MsoNormal"><b><span style="font-size: 7.5pt;">"Guin, Michael"
<Michael.Guin@WSPGroup.com></span></b> <br>
<span style="font-size: 7.5pt;">Sent by: <a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a></span>
<br>
<span style="font-size: 7.5pt;">11/12/2009 06:09 AM</span> </p>
</td>
<td style="padding: 0.75pt;" valign="top">
<table style="width: 100%;" width="100%" border="0" cellpadding="0">
<tbody><tr>
<td style="padding: 0.75pt;" valign="top">
<p class="MsoNormal" style="text-align: right;" align="right"><span style="font-size: 7.5pt;">To</span></p>
</td>
<td style="padding: 0.75pt;" valign="top">
<p class="MsoNormal"><span style="font-size: 7.5pt;"><<a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a>></span>
</p>
</td>
</tr>
<tr>
<td style="padding: 0.75pt;" valign="top">
<p class="MsoNormal" style="text-align: right;" align="right"><span style="font-size: 7.5pt;">cc</span></p>
</td>
<td style="padding: 0.75pt;" valign="top"></td>
</tr>
<tr>
<td style="padding: 0.75pt;" valign="top">
<p class="MsoNormal" style="text-align: right;" align="right"><span style="font-size: 7.5pt;">Subject</span></p>
</td>
<td style="padding: 0.75pt;" valign="top">
<p class="MsoNormal"><span style="font-size: 7.5pt;">[Bldg-sim] ASHRAE 62.1 unoccupied space
minimum outdoor air supply</span> </p>
</td>
</tr>
</tbody></table>
<p class="MsoNormal"> </p>
<table border="0" cellpadding="0">
<tbody><tr>
<td style="padding: 0.75pt;" valign="top"></td>
<td style="padding: 0.75pt;" valign="top"></td>
</tr>
</tbody></table>
</td>
</tr>
</tbody></table>
<p class="MsoNormal" style="margin-bottom: 12pt;"> </p>
<p><span style="font-size: 10pt;">Dear all,</span> </p>
<p><span style="font-size: 10pt;">ASHARE 62.1 2007 deifned zone as an occupied
space. Table 6-1 provides the calculation for different spaces based on
occupancy and floor area of the occupied space.</span> </p>
<p><span style="font-size: 10pt;">If we consider an unoccupied office space at
night (i.e. not strictly a "zone anymore" ); is there any
requirement to provide minimum fresh air wihin the office space. </span></p>
<p><span style="font-size: 10pt;">Thanks in advance for your help</span> <span style="font-size: 10pt;"><br>
Michael </span> </p>
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