Applicability of CPG sections 2.9 and 3.10

In answer to your first question, there does not seem to be a relevant CIR, but your safest approach would be to not attempt a VRF system under the prescriptive approach. You can't deem a section of the CPG as not applicable, you have to meet it's requirements. If you can not do so, then the prescriptive approach can not be achieved by your project. In the previous question, it's an error with the LEED template functionality, less than 5 hp motors do not require VFD's. Here, you're attempting to use a system type not supported by the CPG.

In regards to your 2nd question, the CPG is very clear that if the motor is rated at less than 5 hp, it does not require a VFD. In this case, if it's served by an existing chiller, than the chiller is outside the project scope and does not need to fulfill the requirements of the CPG.

I am working on the project in China (1 floor fit-out) which has 1 Water Sourced Heat Pump that (connected to the condenser water riser) for the server room and the rest of the AC is Chilled Water Fan Coil Units (connected to the Chilled Water Riser). So based on that, the only item I need to consider for equipment efficiency under 2.9 is than only the heat pump since the FCU are not in table of the CPG (CEE) and the FCU are below the treshold for 3.10 - Correct ?

John,

I believe you still have to account for the chilled water system and it's accompanying FCU's in 2.9. If, however, the CPG does not appear to be applicable to your current system, then, as Erik says above, you can not use a prescriptive approach and must use a performance approach.

Thanks Paul: If I have Chiller and Pump outside and only 2 kW of fan power on the FCU what sense does it make to do a performance approach (compared with what system) - John

Paul: 1 more thing: The FCU are provided by the Landlord as part of the Core and Shell work. The only AC added is a Heat Pump for Server Room that meets the CPG requirements - John

John,

I did a little more research, and it's a little nebulous as to what we're looking at here. As far as I can tell, you need to account for whatever energy you're using for space cooling. If it's a build out of only part of the building, you're obviously not going to use all the chilled water that the chiller is producing, however, you absolutely need to account for the FCU's that are in your space. They're the mechanical equipment serving your space.

If the FCU's meet the requirements of the CPG, then you're fine. If they don't or don't seem to apply, then you need to use an ASHRAE 90.1 Appendix G Performance approach, where you account for the entire building, but the only difference between the baseline and proposed building is the HVAC. Then you compare the Baseline HVAC energy use versus the Proposed.

The CPG refers to equipment that are either Split or Packaged Equipment (Fan Coils are not covered). Since the FCU, Envelope and Light Fixtures are by Landord how can I do Baseline vs Proposed ?

This is a Commecial Interior Job and we have only 1 Floor in a 50 Storey Building...............

John,

I just found some information that will ease your heart significantly. I just confirmed that you were right in your original assertion that only the Heat Pump needs to be accounted for. The key idea is that the FCU's and Chiller are outside your scope of work.

Sorry for the confusion. If your heat pump meets the CPG, you should be fine on this credit.

Paul, thanks for easing my heart. We found a unit here in China that exceeds the ARI-ISO 13256-1 rating for CEE Water Cooled Tier 1 (14.0 EER) as there is no Tier 2 according to www.cce1.org 2009 Standards yet. So that should serve the CPG requirements and get us the 5 credits under EA 3.1 equipment efficiency.

www.cee1.org