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NC-v4 EAp2:Minimum energy performance

VRV that controls laboratory ambient temperature should be classified as HVAC system or process

SOLON YANG

Delta Electronics

LEEDuser Basic Member

0 thumbs up

Project location :

Japan

July 10, 2018

I encountered this situation when building the energy model: the laboratory's ambient temperature control was provided by VRV, which was closed, mainly for equipment testing, and the personnel were not inside.
1. I want to confirm that the VRV should be classified as an HVAC system or process.
2. If defined as a process, we use high efficiency VRV, can I create different VRV efficiency in proposed and baseline?
3. What is the reference to the VRV efficiency standard of the baseline of the process?

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Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Tue, 07/10/2018 - 15:55

1. Sounds like an HVAC system if it is providing heating/cooling to maintain temperature for the people who occupy the space. 2. Does not sound like a process load. What is making you think it is a process load? 3. Table 6.8.1J provides the minimum efficiency required for these systems.

David Eldridge

Energy Efficiency Ninja

Grumman/Butkus Associates

LEEDuser Premium Member

64 thumbs up

Wed, 07/11/2018 - 20:45

Do you mean that the laboratory has separate latent and sensible heating and cooling systems, for instance a DOAS for ventilation and then using the VRV for cooling (and maybe heating) in the laboratory spaces? These would be considered "regular" HVAC for modeling purposes. Process cooling would be using the VRV to cool laboratory equipment directly, or perhaps in some cases for cooling data rooms or imaging equipment rooms separately from the need for human occupancy. Another clue might be if the equipment is certified according to the standards referenced in Marcus' post Table 6.8.1J - process equipment might be designed for different temperature criteria.

SOLON YANG

Delta Electronics

LEEDuser Basic Member

0 thumbs up

Sat, 07/14/2018 - 02:55

Thank for your kindly reply. I will explain in detail what you are not clear and hope to get your reply again. At present, 0ur project-one multi-purpose building which has 5 laboratory rooms inside. The function of the laboratory is for equipment testing. Operation person will stay in the laboratory during preparation period, when experiment is running, all personnel must leave the laboratory and equipment is still stayed in the laboratory. Because the laboratory space has different temperature and humidity requirements, so we use VRV to supply cooling and heating in order to maintain the different temperature and humidity requirements of the laboratory. Followings are our problems when we are doing our energy simulation in the LEED project: 1. This power consumption of VRV should be classified as HVAC system power consumption? Or Process system power consumption? 2. If it is a Process system power consumption, when we use high efficiency cooling and heating equipment, or adopt heat recovery, Can we attribute this energy saving value to EAc2 Optimize Energy Performance or not? 3.If the energy saving value can be attributed to EAc2 Optimize Energy Performance, then what is the basis value of Baseline?3.

David Eldridge

Energy Efficiency Ninja

Grumman/Butkus Associates

LEEDuser Premium Member

64 thumbs up

Mon, 07/16/2018 - 19:34

As far as claiming a credit, you may be best served to consider it as HVAC energy. If treated as HVAC, then the baseline case could be:

A baseline system that covers the whole building or floors of a building depending on the area and fuel source table in 90.1 - your building saves energy by having a dedicated system for the lab rooms instead of running the main system to provide the special IAQ conditions.
If justified to have a separate HVAC, the baseline HVAC is a code-minimum system which may be packaged HVAC if the lab area is small.

By treating it as a process, there isn't as strong of a foundation to justify a baseline process that runs less efficiently. If this equipment was chosen for your process, why wouldn't it be standard for any other process? Obviously projects claim savings all of the time for this, but it may be a bigger effort to support the claimed improvement, where treating the VRV as HVAC system provides baseline values provided in 90.1. As a reference point, other laboratories would be HVAC energy, but in those cases the high air exchange rates are for safety, while the temperature and humidity control may be both for occupants as well as experiments.

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Mon, 07/16/2018 - 20:06

What are the temperature and humidity requirements and how do they differ from the other spaces? If the temperatures and humidity settings are outside that required for human comfort and it is a separate system from the system that provides thermal comfort for the occupants, then this would be considered a process load. If it is a process load then it gets modeled identically in the baseline. You could potentially claim savings as an exceptional calculation but will need to provide a good justification for the baseline you choose. It is up to you to justify a baseline system based on standard industry practice in your area for this type of project.

SOLON YANG

Delta Electronics

LEEDuser Basic Member

0 thumbs up

Fri, 07/20/2018 - 14:24

If treated it as process system, when we use heat recovery equipment, can we attribute this energy saving value to EAc2 Optimize Energy Performance or not?
What is the most effective way to prove the benefits of heat recovery? Submit a calculation documentation or specification file. Can you provide an example?

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Fri, 07/20/2018 - 14:51

Usually you can but it is impossible to say for sure without seeing the full narrative and baseline explanation related to the exceptional calculation. If this is an exceptional calculation then you will need to provide a narrative and documents that explain the system in the proposed case, calculations for how you have determined the savings, and a thorough justification for the baseline that you must select and justify. I don't have an example I can share.

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VRV that controls laboratory ambient temperature should be classified as HVAC system or process

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