Engineered Systems - October 2008 - (Page 8)

Letters Launching an M&V plan I have been reading Howard McKew’s columns about an M&V plan (“Tomorrow’s Engineer”). They are really interesting and helpful, as I am in the process of developing a plan now. The building that I am looking at is 16,500 sq meters and has a ground source heat pump as the primary heat source. It also has a complicated airhandling system with a lot of points to measure. We have modeled the building and we will have to calibrate our model in the future. It is our first LEED® building, so there is a steep learning curve here for everyone. simpler the plan, the better. Regarding the Cx plan, I created the Cx 1-2-3 process (www. buildingsmartsoftware.com) where the Cx-1 module combines the Cx plan into a three-part specification so there are not two documents. Other Cx firms will write the plan and then have to duplicate it into the commissioning specification so that you “own” the participation of the contractor, trades, equipment manufacturers, etc., in the contract documents. This becomes really messy if you specify the commissioning in Division 1, 15, 16, and another section of the specification where commissioning is required. Where would you locate the Cx plan? Section 1, 15, 16, or all of them? By creating a Cx spec (Division 17), everything gets located in that section and all other sections of the specification simply refer to this section of the contract documents. The building that I am looking at is 16,500 sq meters and has a ground source heat pump as the primary heat source. It also has a complicated air-handling system with a lot of points to measure. We have modeled thebuilding and we will have to calibrate our model in the future. It is our first LEED® building, so there is a steep learning curve here for everyone. The problem is that LEED does not give any direction on how to write the plan. Do you know where I could find a plan to help me with mine? — Wade Lucas St. John's, Newfoundland and Labrador, Canada Separation anxiety In Kevin Dickens’ article, “Overcoming Hot Aisle / Cold Aisle Separation Anxiety,” published in the May 2008 issue of Engineered Systems, he showed computational flow diagram (CFD) images of data centers with the following: • No ceiling or hot/cold aisle separation • With ceiling plenum but no hot/cold aisle separation • With ceiling plenum AND with hot/cold aisle separation However, he did not show: • No ceiling but with hot/cold aisle separation Was that analysis done, and if not, how do you know that both physical separations were/are important? The problem is that LEED does not give any direction on how to write the plan. Do you know where I could find a plan to help me with mine? I also just finished the commissioning plan but I think it will change as the project progresses. John Hazucha, P.E. Ellerbe Becket Minneapolis, MN Dickens responds: The answer in our particular case is no. The reason is our design required the ceiling because there would be no other path for the return air. Specifically, If you think of each hot aisle as an island with an enclosure from the cabinets to the deck then you can see that without a ceiling plenum or duct work to each “hot pod,” the hot air would have no path back to our mechanical galleries on the perimeter. So that begs the question, is there a design where both vertical and horizontal separation is not required? The smart money says yes, but I would say there are some limits. If you didn’t create hot pods but instead only contiguous hot aisles by eliminating the enclosure doors on the ends of each pod and extending the vertical separation across the perpendicular aisles, then these “hot alleys” could provide an unencumbered path for the hot air back to the gallery with no chance for mixing with the cold air in the cold aisles. But this concept would likely be limited by the width of the data hall. Based on the runs we did with and without ceilings without verti- Wade Lucas Commissioning Specialist Government of Newfoundland and Labrador St.John’s, Newfoundland and Labrador Canada McKew responds: My suggestion is to base the M&V plan around the primary meters (electric and gas, as well as water) to keep it simple. Others write the M&V plan to meter all the energy users, which is a lot to meter, and more importantly, who will do this on a regular basis during the warranty year? Usually the planning and construction group will look for the facility group to budget this activity because it isn’t in the construction budget. The facility group will say they don’t have M&V capabilities or budget in their annual operating budget so the 8 En gi neer ed Sy stem s October 2008 http://www.buildingsmartsoftware.com http://www.buildingsmartsoftware.com

Table of Contents Feed for the Digital Edition of Engineered Systems - October 2008

Engineered Systems - October 2008 Contents Editor’s Note Letters Back2Basics HVAC Challenge Case in Point Commissioning Building Automation HydroTech HVACR Designer Tips Special Insert: Engineer's Technical Library Fall 2008 Living Wild! Chilled Beams in Chicago Phoenix Convention Center: On The Rise Cold-Climate HVAC Challenges Humidification Strategies For Data Centers & Network Rooms Special Advertising Supplement: Tabb Talk Computers & Software Issues & Events Products Literature & Catalogs Glossary Classifieds Advertiser Index Tomorrow’s Environment

Engineered Systems - October 2008

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