Warehouse

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I was just asked this question

Does a 1.5 million sqft ground floor warehouse have to comply with the baseline system in Table G3.1.1A of ASHRAE Std90 (page 176, 2004 Std)? The baseline system would be 7.
Fan Control: Packaged rooftop variable air volume with reheat
Cooling Type: Chilled Water
Heating Type: Hot Water Fossil Fuel Boiler

Assume the warehouse stores lumber or auto tires or some other stuff that is indestructible and does not decay, freeze or breathe. Does it have to comply with the envelope, lighting, mechanical and domestic HW standards? Why can?t a space like this use several packaged rooftop units with gas furnace heating and DX coils for cooling? Does it have to have chillers, cooling towers, HW boilers and VAV systems with reheat?

If there is occasional people activity in the space, what would be the ventilation and lighting requirements? I would think the design of a warehouse depend on what is being stored and the activities in the space. There is a wide variety of possibilities.

Varkie

Varkie Thomas's picture
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Since I got no replies, it was must have been a dumb question. I assume Std90 systems and plant are for the baseline only and for the proposed you can use something else. A proposed packaged VAVS with furnace heating and DX cooling produced nearly the same kbtu/sqft/yr (0.1 difference) as the baseline of chilled water and hot water.

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I?ve modeled a few self storage facilities before, and also had this question. As far as I could tell, System 7 really was the right system for my baseline building, and my condensing furnaces with split system AC units actually had less energy consumption than the chilled water / boiler system. Go figure?

James Hansen's picture
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The warehouse I am looking at is a rectangular building, just under 1.5 million sf and with a ceiling height of 41 ft. Maximum occupancy is 50 people mostly in 12,000 sf of administrative offices with 10 ft ceiling. Why maintain the entire mass of air occupying the space volume in the warehouse at 75 deg F in summer and 70 deg F in winter? Can the proposed warehouse model use just ventilation and save energy. The percent energy savings for LEED certification is enormous. Mechanical floors are heated (to prevent pipe freezing) and ventilated. Underground parking is ventilated. Does ASHRAE Std90 for commercial buildings include industrial buildings (steel plants)? The definition only mentions area and number floors. I might have got it wrong. I have only worked on commercial that house people.

Varkie Thomas's picture
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90.1- in the User's Manual does specify that for spaces that are not conditioned (as warehouses fall into this) your baseline shall have no heating and cooling

Page G21 of the User's Manual specifically reads in reference to Table F3.1-10 the following

"This requirement only applies to conditioned spaces in the building. Semiheated spaces would only have a heating system; unconditioned spaces would have neither heating nor cooling systems."

Jorge E. Torres Coto

Jorge Torres-Coto's picture
Joined: 2011-10-02
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Just speaking from one of my previous projects with a large warehouse component:

- The warehouse was required by the LEED reviewers to be heated and cooled

- I could not just simulate ventilation energy in the proposed case

- I tried presenting my case and showing the effects of conditioning/not conditioning a few variations of proposed and baseline, but had to go to an appeal to finish EA c1 because the review team appeared to change their request during the re-submittal

- It may have been mentioned before, but if I would have known about it from the beginning I would have saved a lot of time/frustration: CIR!

Don?t shoot me for not remembering where it is, but basically it allowed me (and the previous CIR recipient) to move the TSTAT set-points in the warehouse so far out that both heating and cooling would never come on, thus simulating ventilation-only energy. Seems like a sneaky work-around, but by doing this in both models it?s treated as an allowable measure.

Not sure if this helps out in terms of trying to prove the minimum required energy cost savings in any other facility though.

Matthew Higgins, ASHRAE-HBDP, LEED-AP

Matthew W. Higgins's picture
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Matthew,

Besides the responses to my message sent to Bldg-Sim, I received two other responses that said the same thing, that during building operation ?to move the TSTAT set-points in the warehouse so far out that both heating and cooling would never come on, thus simulating ventilation-only energy?. The baseline system for this building would be 7 (Fan Control: Packaged rooftop variable air volume with reheat; Cooling Type: Chilled Water; Heating Type: Hot Water Fossil Fuel Boiler) that provides heating and cooling so the proposed system must do the same. Changing the system to roof top packaged VAVS with gas furnace heating and DX cooling produced a slightly lower Kbtu/sf/yr but the first and maintenance costs and space requirements would be lower.

Varkie

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