Hello, I would greatly appreciate some guidance on the below four queries:
Can a CxA currently on the second required project under the supervision of a suitably experienced senior CxA take on a third project as the main (or only) CxA if the second project has not been completed but is scheduled to be completed well in advance of the third one?
Also, will the manufacturing refrigeration systems for an ice cream factory undergoing LEED certification and Cx have to be commissioned; I ask as these are very bespoke and specialised systems but obviously they are a huge energy consumer with probably potential for savings and improved quality.
Then I wanted to know how a PV plant, supplying three projects of a district certification will need to be handled in terms of its Cx. The three buildings/projects are commissioned by different parties; will only one of them have to handle the PV system?
Lastly, will the water conservation at a project undergoing LEED certification and Cx have to be commissioned due to their energy systems, pumps and controls?
Scott Bowman
LEED FellowIntegrated Design + Energy Advisors, LLC
LEEDuser Expert
519 thumbs up
July 14, 2014 - 10:28 am
Lots of questions, so in order:
I think that a CxA that has been working with a mentor on two projects, perhaps doing most of the hands on activities under the direction of the more experienced person, would be fine to then submit those two projects on a third to take on the role.
No, the ice cream production systems would not need to be included in the Cx for the project, as it is totally process oriented. Typically these systems are already heavily commissioned since they want the product to be right! While the energy model must include this load, the scope of the Cx does not.
The district PV plant is kind of unique. In a way it could be defined as a DES, which does require the “plant” to be commissioned within 5 years of the project (but I am saying that from memory, so would need to be confirmed). My recommendation would be for each project to Cx the connection to the plant, which I assume will be pretty darn simple. Then someone will need to commission the PV plant and inverters and distribution system, and all three projects can then submit that or at least have it ready in case there is a question.
Yes, any water conservation system or rainwater capture, even automatic faucets, needs to be commissioned. If there is any pumping or controls related to this, then it really needs to be reviewed. My experience with these systems for rainwater capture is they can be fairly complex and need adjustment to function properly to maintain water quality and pressure as the system is very dynamic based on use.
André Harms
Ecolution Consulting1 thumbs up
July 14, 2014 - 12:14 pm
Hello Scott,
Thanks so much for the prompt and detailed reply.
I just wanted to clarify the first point:
Whilst I agree with you that it should be fine, is the timing not possibly an issue? The second project still being ongoing as the third commences with the mentor not being available for the third at all; is there a way for me to confirm that this is acceptable or do you think the risk is minimal?
Scott Bowman
LEED FellowIntegrated Design + Energy Advisors, LLC
LEEDuser Expert
519 thumbs up
July 17, 2014 - 9:46 am
Anything could be a possible issue, but I have not seen significant verification from GBCI at this point. You can certainly request a conference call with GBCI reviewer team. That can take a week or so, but they could very well give you direction.
Jorge Torres-Coto
Building Systems Commissioning EngineerEmpirical Engineering, LLC
17 thumbs up
August 22, 2014 - 11:38 am
If the process equipment part of the energy simulation, AND there is an attempt to acquire savings from this process, then it has to be commissioned since every has to be equal through ALL credits. If that is the case, I suggest you stick with whomever is doing start-up and adjusting of the refrigeration, utilizing their process documentation. This should cover you, and save the contractors from doubling efforts. Scott is correct in stating that these process systems have extensive testing and adjusting (most of the time).
We have done many Cx projects at industrial facilities and talk with whomever is doing the energy simulation and facilities to make sure we are all on the same page regarding what is included in each credit.
André Harms
Ecolution Consulting1 thumbs up
August 25, 2014 - 1:51 pm
Thanks for the clarification Jorge, I will check that with the energy modeller about this.
It has also become apparent that a secondary circuit of the process refrigeration plant will provide the chilled water through a heat exchanger to the HVAC distribution system for space cooling.
Do I now have to commission the refrigeration as you suggest?
Similarly with the generation of hot water for processes provides warm water via a hear exchanger to the HVAC distribution for space heating system. How would you proceed there?
Jorge Torres-Coto
Building Systems Commissioning EngineerEmpirical Engineering, LLC
17 thumbs up
August 25, 2014 - 2:06 pm
If no savings is being claimed on the generation side of the HX (cooling and/or heating) I would look at the heat exchanger similar to a Chiller and/or Boiler. Make sure it meets mandatory requirements (balancing valves, motorized isolation valves, etc. if you have more than one unit in parallel), and only Cx the HVAC side of the HX. I would at least make sure the connections have everything necessary on the process side to be able to start-up, balance, test & troubleshoot, since the primary side will have an impact on the secondary side.
Now, if savings are being claimed on the primary side (process) I would include it as part of the Cx Process. If that is the case, your best option is to work in unison with the Process side Contractor. It is possible that the refrigeration system may be taking credit, since baseline criteria exists for refrigeration systems in the LEED for Retail Guide.
Scott Bowman
LEED FellowIntegrated Design + Energy Advisors, LLC
LEEDuser Expert
519 thumbs up
August 25, 2014 - 2:41 pm
I mostly agree with Jorge, but from an energy modeling stand point, you may have just defined a District Energy System, ie the chiller or refrigeration equipment that is making the "cold" is no longer in the building part of the system. This could have significant ramifications on the savings. The input of cold water is now the same for both the baseline and design cases, so if you were using a chiller that is better than what Appendix G requires, you could be leaving some savings on the table.
André Harms
Ecolution Consulting1 thumbs up
September 13, 2014 - 7:55 am
Hello Jorge, hello Scott,
Thanks to both of you for the assistance.
I wanted to clarify which mandatory requirements regarding valves you refer to Jorge.
Also, does this principle apply to other systems, i.e. if one aims to access efficiencies through the energy model one needs to commission these systems?
It seems as though the refrigeration and heat process plants will be claiming efficiencies in the model so we will commission according to your recommendation.
Scott Bowman
LEED FellowIntegrated Design + Energy Advisors, LLC
LEEDuser Expert
519 thumbs up
September 15, 2014 - 7:00 pm
Yes, that is the principle that I apply when defining scope of commissioning services. So if you are including and want to take credit for energy efficiencies of refrigeration or other process loads, then you must commission same. Sounds like an interesting project!
André Harms
Ecolution Consulting1 thumbs up
October 8, 2014 - 10:21 am
Thanks for the feedback some time ago Scott. It is indeed an interesting project and as we are getting more and more involved and the project develops additional details come to light/change.
The latest one I would like your guidance on is that of Modular construction: I have reviewed the Modular Construction and LEEDv.3 by the modular building institute for some input. My difficulty is establishing to what extent must the construction installation checklists be implemented and verified of the modular construction in the factory on the other side of the globe if it will be fully implemented on site during/after assembly and before FPTs are conducted. Would you have some insight and guidance there?
In the above-mentioned document the statements “In the case of modular building commissioning is assumed to be applied to a finished project.” and "[...] systems that are assembled or sub-assembled at the factory which become part of the permanent installation must be commissioned as part of the finished installation.”
indicate that the bulk of the commissioning can be conducted on site, do you agree?
Scott Bowman
LEED FellowIntegrated Design + Energy Advisors, LLC
LEEDuser Expert
519 thumbs up
October 8, 2014 - 12:35 pm
Andre, I do agree with the statement. One thing that is happening more and more is I have heard called "skid mounted equipment" in the mechanical world. That is basically the modular equipment. This means anything from a pumping system to a full chilled water system, everything on a skid, ready to hook up, all components tested in the factory (sometimes with flow), all controls installed, etc.
In this case, you can consider this a piece of equipment, just a very complex one and it is not part of the construction process, so pre-functional checklists would take into account that the modular is being installed, and what actions are required to get that equipment installed and ready to integrate with the overall systems in preparation for the FPTs.
No, I will give one caveat...recently there has been a trend in large urban areas where the construction process is more like off-site than modular. The construction company rents a large warehouse as close to the project as possible, and then constructs modules, including a lot of plumbing in many cases, to then truck to the site late at night for installation. This saves on general conditions related to boundaries on congested sites AND increases both productivity (construction in shelter and conditioning) and quality. In this case, there might be some checklist work that the contractors should do in that case.
André Harms
Ecolution Consulting1 thumbs up
February 11, 2015 - 10:22 am
Hello Scott, hello Jorge, I was hoping you would indulge me one more time on this project for two more queries:
- We have been integrating with the refrigeration (mostly process but supplying chilled water to HVAC via a heat exchanger) plant's commissioning process and getting that up to standard after all. I have now received the ASHRAE 90.1 mandatory provisions forms back for this equipment and it seems as though some of the compressors/chillers EER efficiency is lower than required. However most of them are better than required and the total refrigeration plant (weighted average of the efficiencies) is better than the required value. Will this be acceptable and can we have the designer on record complete the form for one average plant?
Hello Scott, hello Jorge, I was hoping you would indulge me one more time on this project for two more queries:
- We have been integrating with the refrigeration (mostly process but supplying chilled water to HVAC via a heat exchanger) plant's commissioning process and getting that up to standard after all. I have now received the ASHRAE 90.1 mandatory provisions forms back for this equipment and it seems as though some of the compressors/chillers IPLV efficiency is lower than required. However most of them are better than required and the total refrigeration plant (weighted average of the efficiencies) is better than the required value. Will this be acceptable and can we have the designer on record complete the form for one average plant?
- the process area, substation and utility room are intended for continuous operation and thus so is the HVAC system serving these spaces (besides shutdown minimal preventative/scheduled maintenance of the HVAC system). I note that ASHRAE 90.1-2007 calls for motorised dampers (and in the case of this max 2 story building, allows gravity dampers) §6.4.3.4.2 and §6.4.3.4.3. The former exempts the dampers for unconditioned spaces but the latter does not have this exclusion (whilst ASHRAE 90.1-2010 does have an exemption for ) and neither have exemptions for manufacturing spaces that run effectively continuously. Do you have guidance on both the need for gravity dampers in this situation for unconditioned spaces as well as continuously operating spaces/systems (they are not always the same)
Scott Bowman
LEED FellowIntegrated Design + Energy Advisors, LLC
LEEDuser Expert
519 thumbs up
February 11, 2015 - 11:05 am
Andre, I am thinking you might want to ask part of this question over on the EAp2 part of LEED User. Marcus would be much better on answering the question related to "mandatory" requirements of 90.1. If I understand, the refrigeration plant is for process, which would not be covered by 90.1, but is being used to make chilled water for the building, which is covered by 90.1. So the first thing to determine is the primary function of the equipment.
That being said, it is important to know that the overall energy use of the plant WITH process will need to be accounted for EAp2 and EAc1, and if you plan on proposing any energy savings from the process side, you had better be ready to present good arguments on what the baseline is for the industry.
As to the second part of the question, I am totally lost. I no longer have access to the specific language in 90.1, so cannot really comment on that question.