FAQs about EAp2 :

Can the Passive House Planning Package (PHPP) be used to energy model for LEED?

Is it acceptable to model a split-type AC with inverter technology compressor as a heat pump, like modeling VRF?

Can the Trace 700 'LEED Energy Performance Summary Report' by uploaded to LEED Online in lieu of the Section 1.4 tables spreadsheet?

A portion of our building envelope is historic. Can we exclude it from our model?

Which baseline HVAC system do I use if my building has no heating or air conditioning?

For an existing building, do I need to rotate the model?

Our project has a diesel backup generator. Should we include it in our energy model?

Our project has a large process load—75%. Despite our efforts to make an efficient HVAC design, the cost savings are minimal. What can we do to earn this prerequisite and be eligible for LEED certification? Is there any flexibility in how we model the p

Can SHGC be higher in the proposed than in the baseline model?

Our process load is higher than 25%. Do we have to justify that?

Do I need to justify the electrical and fuel rates I am using in my model?

Our local code references ASHRAE 90.1-2010. Should I use that for my documentation, or 90.1-2007?

Can I claim exterior lighting savings for canopy lighting even though a baseline model cannot include shading elements?

The project is built on a site with existing exterior lighting installed. How should this be accounted for?

Can mezzanines open to floors below be excluded from the energy model?

How do I provide a zip code for an international location?

For a project outside the U.S., how do I determine the climate zone?

For a project outside the U.S., how do I determine the Target Finder score?

Do hotel rooms need automatic light shut-off control?

How commonly are the 90.1 mandatory compliance forms submitted as part of EAp2/EAc1?

View answers »

Forum discussion

NC-2009 EAp2:Minimum Energy Performance

Modeling Electric Unit Heater

I have to model electric unit heaters in HAP for spaces like Stairs, Trash rooms, Vestibules etc. The issue is that the Stairs are already served by heat pumps and electric unit heaters will turn on only to maintain the space setpoint when the heat pump is not sufficient. How should I model a schedule for this type of system in HAP? Also how do I model a system like this without double counting the stairs in baseline and proposed cases?

Nishank

0

You rely on LEEDuser. Can we rely on you?

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

Go premium for $15.95  »

Fri, 05/11/2018 - 13:34

Not sure about HAP but most software allow you to model supplemental heating in a space. The electric unit heater should come on in response to the heat pump's ability to meet the load in the space. I would not schedule it but select some other means to control its operation like a thermostat. If you can't model both systems in the space then you should create a different zone for those spaces, proportion the load, and model a heat pump with electric back up. It should be thermodynamically similar.

Fri, 05/11/2018 - 13:59

Thanks Marcus, So to make sure I understand it correctly, I need to divide the load proportionally between the water source heat pump and electric unit heater, create a separate zone (therefore a separate system) for the electric unit heater which will serve the proportionally divided load and proportionally divided area (since I don't want to double count the space) and then create a baseline using the same approach? 

Fri, 05/11/2018 - 14:40

So you can't model a supplemental heating source in HAP? That is by far the best way to do this. You should not proportion the load between the two systems. You should create a separate zone of those areas and proportion the load between the two zones. The zone with the electric unit heater would include a separate heat pump with the same efficiency using electric heat as the back up.

Fri, 05/11/2018 - 15:11

Unfortunately not. The way HAP models WSHP is only with its set of equipment, meaning cooling tower and auxiliary HW boiler. It cannot model supplemental heating in the form of electric heat in the same system..

Fri, 05/11/2018 - 15:31

So model an air heat pump with a similar efficiency as the WSHP. This should get you close. You could downgrade the efficiency a little to account for the impact on the water loop. You might also call HAP and ask them for a work around. It would help to document what you are doing for the reviewer.

Fri, 05/11/2018 - 15:49

I'll do that. Thanks for your help.

Mon, 01/13/2025 - 16:33

Hi Nishank, I would like to know how you ended up modelling the Supplemental Electric Heater? I am stuck at a similar design here with HAP.

Add new comment

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