See all forum discussions about NC-v4 EAp2
 Subscribe to new posts about NC-v4 EAp2 Post a new question aboutNC-v4 EAp2
See LEEDuser’s guidance on NC-v4 EAp2»
FAQs about EAp2 :

Do the required savings for this prerequisite (and credit) need to come only from building energy, or also process loads?

Our project doesn't have enough energy savings to earn the prerequisite. Can we get there by incorporating onsite renewables?

Our proposed design has insulation R-values that are below those prescribed by ASHRAE 90.1-2010. Can we still meet the prerequisite?

View answers »

Forum discussion

NC-v4 EAp2:Minimum energy performance

Energy Simulation

Hello Marcus, i want some clarification regarding HVAC Baseline and Proposed model. According to Table G3.1.1A and Table G3.1.1B and as per proposed building type and heating fuel the HVAC baseline in our case is System 6(Packaged VAV with PFP Boxes) . My proposed design HVAC system Chiller based. Now i am going to simulate these systems on software. 1 In simulation software i select for proposed case chiller (plant) but in baseline i select the packaged rooftop system. Is it correct or not or select the same system for both model? 2 Select same system (Packaged rooftop )in both model but use different specification i.e(Fan power, cooling,heating capacities) is it okay or not?

0
Post a reply

You rely on LEEDuser. Can we rely on you?

LEEDuser is supported by our premium members, not by advertisers.

Go premium for $15.95  »

Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Tue, 06/28/2016 - 13:51

1. Correct. The systems should be different. 2. No. I am guessing that your proposed system would have air handlers not packaged systems.

Tue, 06/28/2016 - 13:58

1.Yes Proposed system have air handler and baseline have package rooftop.i selected these both systems but end saving going to negative.

Tue, 06/28/2016 - 15:26

Is it possible i simulate the both model identically without heating coil due to software limitation.
Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Tue, 06/28/2016 - 14:13

No you must model the proposed as designed and the baseline according to Appendix G.

Tue, 06/28/2016 - 15:51

Thank you Marcus 1.When i select HVAC baseline System 6 "Packaged rooftop VAV with reheat" heating is not show in end report. when i include the preheat coil in baseline system the heating is show in end report. Is it acceptable or not. 2.what about the ventilation sizing method. It is identically or different in both model i.e proposed model ventilation sizing method is "SUM OF SPACE OA AIR FLOW". and in baseline model as per "ASHARE std 62.1".
Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Wed, 06/29/2016 - 15:23

1. Not enough information to say. If there is heating energy use in the baseline and no heating energy use in the proposed it will likely not be acceptable without a thorough explanation. 2. That sounds like the correct methods. Make sure the quantity of OA is identical unless you have demand controlled ventilation in the proposed.

Wed, 06/29/2016 - 16:30

Thank you Marcus, Yes heating energy used in both models. The problems becomes only in Baseline Model. The software has no provision heating in VAV system. if i select the Preheat coil, the heating is showen in output summary. Now the question is that Can i use the "Preheat coil" only in Baseline model for heating.
Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Wed, 06/29/2016 - 16:44

Sorry i was confused on your previous post. You should be able to model electric reheat coils in the baseline system in HAP. The heating in the baseline must be reheat coils, it can't be only in the preheat coil. You can only model a preheat coil in the baseline if G3.1.2.3 applies to your situation.

Add new comment

To post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.