[Bldg-sim] ventilation only & LEED

[Jason Glazer]

Please note that 90.1-2010 has new baseline HVAC system 
types for heated only storage which are heating and 
ventilation units. It also contains an allowance for fan 
power related to non-mechanical cooling fans.

Jason

On 6/1/2011 11:22 AM, Jorge Torres-Coto wrote:
> Christian,
>
> For good or bad, I have ended up modeling many Warehouse
> Distribution Centers, which in essence have a very small
> front office and a very large warehouse that is only
> ventilated (by code). I have had to argue with LEED
> reviewers this point, fortunately successfully. The
> warehouse area is by definition "unconditioned space", just
> like Nick states. Though you still have to model an HVAC
> system per ASHRAE, but spreading the setpoints basically to
> outside air design conditions. The reviews I have had have
> made it through this way. By doing this with the setpoints,
> you will not have any unmet hours. But you are still
> providing the right amount of ventilation air per 62.1 and
> the right power for all the fans. The office is a totally
> different story, which you pretty much know the answer to.
>
> I have had the comments go both way on the following. Since
> the Warehouse is not conditioned I had one reviewer tell me
> to change the Baseline HVAC system to packaged units due to
> the fact that the only conditioned space was a tiny 10,000
> sq.ft. space. Other reveiwers have left me keep my standard
> ASHRAE System 8 baseline with the modifications mentioned
> above for the warehouse area. (I usually utilize two air
> handlers: one for warehouse and one for offices).
>
> Jorge E. Torres Coto
>
> 4830 Viewridge Ave.
>
> San Diego, CA 92123
>
> p 858.751.0933
>
> f 858.751.0937
>
> c 858.688.6088
>
> ------------------------------------------------------------
>
> *From:*bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf
> Of *Nick Caton
> *Sent:* Wednesday, June 01, 2011 7:34 AM
> *To:* christian stalberg; bldg-sim at lists.onebuilding.org
> *Subject:* Re: [Bldg-sim] ventilation only & LEED
>
> Hi Christian,
>
> A LEED reviewer brought up this issue for a
> heated/ventilated-only garage space recently. Owner did not
> want a cooling system beyond ventilation, and one was not
> designed. Ultimately, our reviewer cited TG3.1.1.b / G3.1.10
> directly, and I conceded to model baseline-esque cooling
> systems in both models.
>
> I’m not sure section 2.2 is a great defense as it states the
> standard doesn’t apply to *envelopes* without a
> heating/cooling system… not ventilation systems (2.2.b.). A
> better defense is if your warehouse is by 90.1 glossary
> terms an /_unconditioned space_/, by virtue of not meeting
> any of the three /_conditioned space_/ definitions. In that
> case, I think you could flatly reject TG3.1.1.b as “not
> applicable” if it were brought up. In our garage space
> above, this wasn’t an option as it was definitely a /_heated
> space_/ (see glossary for underlined terms).
>
> I’d agree modeling both models with ventilation only is the
> intuitive thing to do in the context of a validation (LEED)
> model. The intent of this language however, if I’m not
> mistaken, is to discourage/punish design decisions to omit
> heating and/or cooling systems entirely to save energy.
> Never mind that’s actually a very effective strategy, under
> the right circumstances and in moderation… I’ve got some
> contrarian opinions in this department, so I’ll keep my
> mouth shut =).
>
> ~Nick
>
> cid:489575314 at 22072009-0ABB**
>
> **
>
> *NICK CATON, E.I.T.***
>
> PROJECT ENGINEER
>
> Smith & Boucher Engineers
>
> 25501 west valley parkway
>
> olatheks 66061
>
> direct 913 344.0036
>
> fax 913 345.0617
>
> www.smithboucher.com__
>
> *From:*bldg-sim-bounces at lists.onebuilding.org
> [mailto:bldg-sim-bounces at lists.onebuilding.org] *On Behalf
> Of *christian stalberg
> *Sent:* Wednesday, June 01, 2011 5:32 AM
> *To:* bldg-sim at lists.onebuilding.org
> *Subject:* [Bldg-sim] ventilation only & LEED
>
> The warehouse section of our facility in El Salvador is to
> be ventilated only. The textile section of the same building
> will be cooled and humidity will be controlled. Other areas
> such as offices and cafeteria will be cooled. There is no
> heating load in El Salvador. I reviewed inquiry 5088 (copy
> below) which would suggest the warehouse should be modeled
> with air conditioning in both the base case and the proposed
> case even though no cooling will be provided. Our building
> is a little different than the building in inquiry 5088 in
> that it has no heating load. Therefore by the 90.1 standard,
> the standard does not apply (section 2.2) and it is an
> unconditioned space. We feel the ventilated section of our
> building should be rated based on energy savings of standard
> ventilation equipment versus the proposed high efficiency
> fans and louvers that we are providing for ventilation. We
> would like to proceed with the ventilated enclosures being
> included in the model without heating or cooling. Please advise.
>
> Inquiry Number:
>
> 	
>
> **5088**
>
> MPR/Prerequisite/Credit:
>
> 	
>
> EAc1: Optimize Energy Performance
>
> Posting date:
>
> 	
>
> 11/27/2007
>
> It is not acceptable to allow spaces to exceed the unmet
> load hour requirements of the ASHRAE 90.1-2004 Appendix G
> methodology. This is a similar situation to naturally
> ventilated spaces, which are required to include cooling
> systems to meet space loads in the proposed case even if the
> actual building will contain no cooling. Building owners may
> always choose to turn off HVAC systems, or not have them
> installed at all to conserve energy, but the ASHRAE modeling
> protocol assumes that cooling systems will be installed and
> run with sufficient capacity to meet space loads. The
> applicant may use a set-point of 80 degrees Fahrenheit for
> the maintenance bays, but cooling system capacity must be
> increased until the requirements of ASHRAE 90.1-2004 section
> G3.1.2.2 are met. The project may still receive credit for
> using an efficient cooling system as compared to the ASHRAE
> baseline cooling system.
>
> Inquiry []
>
> 	
>
> Our project is located in Las Vegas and consists of a
> combination of office spaces and maintenance bays for
> earth-moving equipment. The owner is a large agency that
> sells, rents and repairs such equipment; these repairs are
> done both inside and outside the building envelope. The
> maintenance bays are occupied by mechanics and will be
> conditioned with evaporative coolers and gas furnace heat,
> the system supplies 100% outside air. This cooling system
> provides conditioning of the spaces but is not able to meet
> all peak loads for a climate such as Las Vegas even when
> these spaces are modeled with higher setpoint at 80 degrees.
> In reality, if the maintenance bays go above the temperature
> setpoints, the mechanics will continue work in the warmer
> conditions or take a break. This is not difficult for
> maintenance bays, where some of the work will also done
> outdoors with no conditioning at all. The owner does not
> want to fully condition the maintenance bays with the
> intention of achieving high levels of energy efficiency. We
> propose the following modeling approach for EA Credit 1.
> -Baseline model will have a mechanical system based on Table
> G3.1.1A of Appendix G with 80 degree temperature setpoint
> for the maintenance bays. -Proposed Design model will have
> the system as designed in the building that provides partial
> conditioning with the same 80 degree temperature setpoint.
> We will not model additional compressor cooling for hours
> where the system is not able to meet loads. This approach
> will result in exceeding the difference in the unmet load
> hours beyond 50 as required by Appendix G. However, this is
> a conscious decision by the owner who wants to maximize
> energy efficiency by providing limited conditioning through
> evaporative cooling for the maintenance bays, and allow the
> temperatures to float higher during peak conditions. We feel
> that this approach appropriately captures the intent of the
> design, and gives credit to the energy efficiency measures
> being taken. It also provides a way for demonstrating the
> value of an energy efficient approach to the community in
> Las Vegas where compressor cooling is increasingly used,
> often indiscriminately; this is a desert climate and a
> different approach to comfort and conditioning is possible.
> Is this approach acceptable? If not, can you advise us on an
> alternative approach that addresses the desire of the owner
> to demonstrate high levels of energy efficiency for using
> such a system?
>
>
>
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-- 
Jason Glazer, P.E., GARD Analytics, 90.1 ECB chair
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