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Active Green Roofs by pablolaroche

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2013buildingefficiencyjudges 2013buildingefficiencyjudges

Jul 8, 2013
09:08

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Dear pmlaroche, Thank you for your submission and congratulations on being selected as a finalist for the final judging round. Our advice for the finalist round would be to try and further develop the sections on what actions you propose and who will take those actions. In short, the idea is very compelling, but we would like to see it developed in such a way that is more actionable.

Megan Miller

Jul 9, 2013
06:49

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Good luck Pablo!

John Peterson

Jul 14, 2013
09:37

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This is not a very viable solution given the modern built environment. Other technologies and methodologies are cheaper and far more effective for energy reduction and GHGs.

Bennie Johnson

Jul 14, 2013
10:24

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Nice proposal Dr. La Roche. Let me know if you need any help.

Pablo La Roche

Jul 16, 2013
02:29

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Hi GDCM Thanks for taking the time to write a comment about my proposal. My proposal combines the simplest, cheapest oldest passive cooling strategy -ventilation- with green roofs which have a higher first cost than a regular roof but a lower real cost for the building and the environment. As with any strategy there are limitations. There is no ideal solution for all types of buildings and for all climates. This is the case with this proposal and probably with all proposals.I am expanding my proposal and I hope that when you read it again your concerns will be addressed.

Pia Jensen

Jul 18, 2013
04:07

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Great idea but I'm thinking it can go deeper Earthship Biotecture earthship.com Earth Bermed Houses houseconstructionz.com/?p=1121

Suhas Babtiwale

Jul 18, 2013
07:20

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highly supported

Pradnya Nagarkar

Jul 19, 2013
08:23

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Good luck to you and your team! Wish you much success.

Anu Agarwal

Jul 19, 2013
09:29

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Every small step in the right direction will make a difference. Good luck team !

2013buildingefficiencyjudges 2013buildingefficiencyjudges

Jul 29, 2013
02:29

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Comments from the Judges are listed below: - Very thorough, well thought out and technical proposal. Excellent team. Needs to indicate what makes up the green roof vegetation (would prefer food or local vegetation, and in this case drought resistant!) and how can the run-off water be reused in the building? How much electricity does it use? I assume it would be nothing like depicted and would prefer a more representative graphic. Would also like to see emissions reductions scaled up to at least a region. Right now, it's only the emissions reduction from one project. Doubtful this can be scaled onto existing buildings without structural support. Great research, but doesn't seem easily scalable. - A lot has already been invested in this idea/supporting research. It seems very implementable. - Nice presentation. The system appears potentially expensive to construct and will require a complicated HVAC system and controls. Would be beneficial to develop detailed cost estimates.

Pablo La Roche

Aug 12, 2013
07:37

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Thank you for the comments. Yes, the vegetation will in fact be drought resistant. Plant species typically used on extensive green roofs are crassulacean acid metabolism (CAM) that are capable to survive in low nutrient conditions, drought conditions and extreme temperature. At this point we have a palette provided by the landscape architect that includes species such as sedum spurium, sedum tectractinum, thymus praecox, and veronica pectinata. The project proposes using water condensed from the air conditioning system for irrigation in warm days when the AC is operating as alternative water source to reduce irrigation demand. Our mechanical engineer estimated about 96 gallons of water per day for 4 hours of operation of the cooling system with an outdoor design temperature of 85 F. This is equal to 0.06 gallons of water/sq ft per day. Since rainfall is only about 12 inches per year we are not proposing to use water runoff in this project. Most of the rainfall will be retained by the green roof and whatever does not stay there will be used to recharge the local aquifer. No rain water from the roofs will drain to the ocean. Regarding electricity use, we calculated the savings with an energy modeling program for this specific high school in this location using local weather data. We estimated a reduction in cooling energy of about 52% (54 Kbtu/ft2/yr) from the proposed design (103 Kbtu/ft2/yr) which is already lower than a California energy code compliant building’s cooling energy (143 Kbtu/ft2/yr). The graphical representation is as close as we can represent it now. We have depicted the location of air conditioning ducts and structural systems using our current BIM model which is developed together with our mechanical and structural consultants. It would be great to see emissions reduction for a region but we would have to model the performance (or obtain utility data) of different building types and then multiply by their roof surface. This is currently out of our scope of work but we will do this in the next phase. For now, Irvine Unified School District will provide us with the roof area of their buildings so we can estimate emissions reductions if all of their buildings used this system. Hopefully we can include this number before the end of the month. We think that this proposal is easily scalable to different types of commercial buildings. The control systems are not more complicated than those in current BMS systems. In fact, we ran some of our test cell series with a simple off the shelf win100 5-2 programmable outlet thermostat. It could also be implemented in residential buildings with some modifications but we have not developed this option yet and lower floor to ceiling heights could be a challenge. We have developed detailed cost estimates for this specific demonstration case and we expect a simple payback in about 18 years. We have not developed detailed cost estimates for other cases but would expect simple payback time to be between 15 and 20 years. In warmer and drier climates it should be shorter, and in colder climates it could be longer or non existent, however we have not done these calculations.

Cybele Shorter

Aug 26, 2013
08:18

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Dear Pablo, I like your proposal and have therefore voted for it. I would like to leave you with my reflections. I may have missed some detail scanning the contest quickly but I see the benefits of your design for their passive strengths and seasonality. It is a shame your application is not integrated in terms of retrofitting or in terms of human social spaces. I think your proposal would benefit greatly from teaming the green thermo efficiency with the ability to interact with the gardens for food and community. Particularly in innercity areas, at first thought I can conceive your idea being overlayed on high rise buildings with your controlled thermal space being the current waterproof roof top areas. Your approach in isolation limits it's opportunity to new architecture. However even in your modelling of new single storey spaces, nowhere do I see you integrating the green space in a way that it creates the added benefit of socialisation to the environment. Unattended gardens just die. Plants taken out of a balanced ecosystem require constant intervention from their human hosts. Please consider the requirements of the plants more and then you will couple the added benefits of community connectedness with the environment. Good luck in this competition, as well as continued application of your excellent systems. Cybele

Pablo La Roche

Aug 27, 2013
04:38

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Dear Cybele Thanks for voting for our proposal. I appreciate your comments VERY much and I think your input is very helpful. I absolutely agree with the importance of interacting with the green roofs and using plants that can provide food to the community. I like what you say about inner city areas in which they would serve a dual purpose. The system could work also with food producing plants and of course if they are accessible and designed so they can be used intensively by the community then they are so much better. There is no reason why this could not happen and I think that we could have shown more options illustrating this. The images we are showing are for a specific case study in which we are implementing the system, we could have also shown additional conceptual options as you suggest. This specific green roof can be seen from neighboring buildings and we extended it down the walls so that the students could interact with the green wall / green roof because it is by a main axis in the campus. BTW I also like how you say "Please consider the requirements of the plants more and then you will couple the added benefits of community connectedness with the environment." I think this is a sometimes forgotten additional benefit of many passive systems. BTW I am providing a link to project that we did for Tijuana Mexico in which we provided a vegetated roof with food producing plants. http://www.ncarb.org/en/Studying-Architecture/NCARB-Award/Prize-Grant/NCARB-Prize/2008-Prize-Winners/~/media/A17C933C824340A9BC72ECC4A1B569D7.ashx http://www.ncarb.org/en/News-and-Events/News/2008/04-California-State-Polytechnic-University-at-Pomona-Awarded-25000-NCARB-Prize-Grand-Prizee.aspx I could not find the link to the boards. We actually built it with food producing plants in a second phase. Thanks Again, Pablo