A client wants to utilize our Zypho Drain Water Heat recovery system for a hospitality project. The client wants to confirm the availability of LEED credits. My understanding is that while the units are eligible for an Innovation Design Credit for LEED for homes. The unit does not qualify for ID credit for hospitality application but does qualify for EAp2 and EAc1 credit in exceptional calculation method. Given the fact that I am new to the LEED applications, my question is based on the following factors: Our DWHRS units have third party certification from KIWA Labs certifying 32.5%+ energy efficiency for hot water showering. Based on KIWA's certification the calculated energy savings for a 150 room hotel with average of 2 showers per room per day, with 10 minute showers. Based on certified performance the average annual savings for the hotel would be 113,700 kWh's per year. Based on an average electric usage of 14kWh per square foot, the hotel having approximately 65,000 square feet, would have estimated annual electric energy consumption of 910,000 kWh's. How many credits would implementation of the Zypho unit qualify the developer for?

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Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Thu, 04/30/2015 - 20:24

You are correct that this strategy would contribute to earning EAp2/EAc1 points. The calculation of points is based on a percent difference of the building as designed/constructed to an ASHRAE 90.1-2007 Appendix G baseline building. The energy cost comparison is based on the results of energy simulation software. There are far too many factors involved in the calculations to say how many points your system would earn on a given project. You really can't take an average energy use and get there. In any case the strategy does need to be submitted as an exceptional calculation showing all of the inputs used and calculations performed along with a narrative explanation and product information as applicable.

Jean Marais

b.i.g. Bechtold DesignBuilder Expert

LEEDuser Basic Member

581 thumbs up

Mon, 05/04/2015 - 09:34

If a software can explicitly model the technology, I guess an exceptional calculation is still needed (i.e. a baseline of the technology is required to support the case), but in this case it sounds weird, or? I mean a baseline building of 2007 does not have this technology. What about PV panels? Do you need an exceptional calculation for those too?

Marcus Sheffer

LEED Fellow

7group / Energy Opportunities

LEEDuser Expert

4454 thumbs up

Mon, 05/04/2015 - 13:27

I suggested an exceptional calculation since it appears he is doing the calculation outside the modeling software. If the software can model it then you are correct that no exceptional calculation would be needed. The baseline would not include this strategy. PV panels are renewable so they come under Section 1.8 in the form. You need an exceptional calculation under three circumstances - when doing a work around in any software, when you need to violate a modeling protocol to show savings (i.e. schedule change), or to show process load savings (or any savings calculated outside the software).

Jean Marais

b.i.g. Bechtold DesignBuilder Expert

LEEDuser Basic Member

581 thumbs up

Mon, 05/04/2015 - 13:41

Thanks Marcus.

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