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[EnergyPlus_Support] Re: Question on Multiple zones per floors
This is a great discussion. I am really understand and agree with your explain. Almost of the time users and including me are easy to get confuse with baseline model, and also a few experience on HVAC.
It may need to define what I really want to get and find the strategy to be applied.
I know that ASHRAE compliant does not provide high building performance, including LEED, but it just guiding information to start with.
My research has started by using ASHRAE 90.1 as baseline because I know this is not best strategy to define the best building performance. The next phrase I will get into high building performance , which has to balance building cost and performance.
Thanks Dr.Li again for great opinion and thought.
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
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> EPlus has many components to simulate HVAC. Because many users ask for components according to the ASHRAE guide lines without understand the implication, the syntax becomes more and more complicated. Many components are schedule controlled without the control and driver element simulated. In VAV for example, only the sensor locations are used to control a setpoint temperature or air volume. Most users cannot figure out how to enter the names of the objects in the sequence of the program class listing order. Therefore, the templates are introduced. Using a few templates and the zone names, a complete zone, system and the plant sections of IDF can be generated. The problem now is that the fields in the template have many options. User with no HVAC experience does not know what they mean. If the IDF editor is not used to examine the options, many features are missed. I am retired, and am not involved with the LEED certification, and is therefore not a member of ASHRAE to get their documentation. As an electrical engineer, I have been involved with many systems of different sizes. The largest one is those used for Wireless transmitter of magawatt capacity. The tube or thermionic valve is steam cooled, and the tower is mounted on top of a swiming pool, and pool water is used to cool the steam loop. In my spare time I am helping some of the PhD students on the use of EPlus. I have been following the EPlus development since 2006 when I of my former student who had started a PhD program, had problem using the EPlus. EPlus has change a lot since then. So if you have problem related to the coding of EPlus may be I can help. Interpreting the ASHRAE document does not seem to be that hard, when a few of them were posted in the forum. There are 16 RefBuildings in the example file folder for one location. There are others for different climate zones in the EPlus home site. That was the reason why I do not understand many users are generating the base line buildings. The generated buildings are all different and with errors. After your explanation, I understand the user problems a little better. However, I am still not going to define my own base line building using the ASHRAE guide line. For a large system, I understand the need to reduce maximum demand load in order to reduce the maximum demand charge by the utlity supplier. This is cost saving and not energy saving.
> Dr. Li
> To: energyplus_support@xxxxxxxxxxxxxxx
> From: oscarhernandez_81@...
> Date: Fri, 25 Nov 2011 07:57:30 +0000
> Subject: RE: [EnergyPlus_Support] Question on Multiple zones per floors
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> I am totally right with you! But in France, We have a hugh problem, the most important thing is to have a certification (LEED, HQE, BREEAM, etc) but in reality we dont know what we do. The consulting companies has to explain the right way to design a buildint not to sell anything without sense.
> Where I work we have this problem, we do beacuse the project owner wants. everything is about money. Build the high performance building in terms of energy is very simple but combine thermal confort, IAQ, and energy consumptions is more complicated. And we don't know how to do it.
> I use Eplus and i will continue, I find a very good way to improve your building. the only thing is the HVAC is a little complicated to use it.
> Best regards,
> Oscar HERNANDEZ
>
> To: energyplus_support@xxxxxxxxxxxxxxx
> From: yli006@...
> Date: Thu, 24 Nov 2011 16:00:18 -0500
> Subject: RE: [EnergyPlus_Support] Question on Multiple zones per floors
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> Hi, Oscar
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> From what you have described, you have to read the ASHRAE guilde line to design a baseline building which is the same as your proposed design in size and shape, and then to improve your proposed design using a different HVAC.
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> This does not really make sense. No wonder so many users are confused. When I ask why are you doing this way, the reply I got was always the baseline building was designed that way. The baseline building uses DOAS, therefore I must use DOAS.
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> From what you have described, it was the person who interpreted the guide line as to use DOAS, and therefore uses DAOS.
> =================================
> In energy saving the important thing is to use sufficient insulation for Winter. Control the heating load in the building in Summer. Use solar to exist heating in Winter, and avoid solar heating using external shades and insulation in Summer. Use natural lighting and ventilation whenever possible.
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> In Canada, the buildings are to recommended insulations for ceiling and external walls. Good insulation and seals for windows and patio doors, etc. Vent the dryer and kitchen heat out of the building, etc. These are minimum requirements.
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> In many so called baseline buildings I have seen in this group these general rules are not obviously of sensibly observed, or tested. The user followed complicated schedule, un-realistic temperature set points and controls, because they are mentioned in the guilde lines. Uses VAV, VRV , etc does not really know what they are.
> ==============================================
> Recent discussions were on how to use simulation short cuts. How to reduce the number of zones, etc. This is not a problem for me as it is not difficult to enter building surfaces directly in EPlus. A paper plan must be used to help entering the vertix numbers.
> ==============================
> To me, the important calculation such as solar and building surface properties are important. Simply using a material listed in ASHRAE data sheet is not the answer.
> The user must understand what the material represent in real material and in the value of heat transfer character listed.
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> The temperature across the wall is an indication whether the material and construction is of the correct type. The Canadian standard R4, R6, R12, R24 values for wall are very easy to compare. ASHRAE uses U-values. in decimals. User worries about minor differences.
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> In real life, it is also the balance between building cost and energy usage cost.
> ========================================
> The other issue is the comfort standard. If the ASHRAE comfort stand is not a requirement, the conditions can be quite different. The ASHRAE standard assumes the clothing is removed in Summer. In fact this is not true in the tropics. Loosely covered body is more comfortable and feels cooler than an skin exposed sweaty body.
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> That is why I feel that different counties with different cultural standard or custom, and climate should have their own standard and guide lines.
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> Chinese pagoda is an example of a small high rise construction. The forbidden city in Beijing has many unique features. Spacious family housing rather than a single studio, in a high rise condo. The apartment building in Singapore used to be the same as the penthouse in North America, for all floors. One unit across the building with through ventilation,or an air well in the middle.
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> I find the EPlus very useful to do building design improvement.
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> Dr. Li
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> To: energyplus_support@xxxxxxxxxxxxxxx
> From: oscarhernandez_81@...
> Date: Thu, 24 Nov 2011 14:14:13 +0000
> Subject: RE: [EnergyPlus_Support] Question on Multiple zones per floors
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> The baseline is your building, the actual building. You have to model the building according to the ASHRAE 90.1. You have an HVAC default system, envelope and everything. This baseline it's not so simple, because you have to read carefully in order to apply the correct assumptions according to the ASHRAE 90.1.
> Design builder cannot import the idf file in order to adapte it in you building. It's weird because Design builder uses E+, so if we can import an idf file, I think was intetionnally made by DB.
> E+ plus has many idf files that could help you to model the ASHRAE baseline building but you have to adapte the idf file to your new building.
> I think the DOE has a lot of information about energy performances. This Baseline it's not a high performance building, the new or proposed building has to be the better. Or you couldn't not have the LEED points. The baseline it's only a reference according to the USA experience. But We know that its not the same.
> Here in France sometimes it's very complicated to apply this regulation. We have many others that are complicated also, so with a new one, we are very confused.
>
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> To: energyplus_support@xxxxxxxxxxxxxxx
> From: yli006@...
> Date: Thu, 24 Nov 2011 07:55:22 -0500
> Subject: RE: [EnergyPlus_Support] Question on Multiple zones per floors
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> If this base line building is the as the reference building in EPlus, the building itself is not energy efficient.
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> Therefore, I do not normally border to compare with it.
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> Thank you for your information.
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> If this base line building is the EPlus reference building, the building surfaces are already defined. Why are the users still have problems with the building. May be it is because the IDF cannot be imported to DesignBuilder.
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> The small office reference building is a 5 zone building with a roof.
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> Dr. Li
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> To: energyplus_support@xxxxxxxxxxxxxxx
> From: oscarhernandez_81@...
> Date: Thu, 24 Nov 2011 08:42:43 +0000
> Subject: RE: [EnergyPlus_Support] Question on Multiple zones per floors
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> Hi Dr Li,
> in this moment I try to model a office building accrording to the appendix G (prm). im not really sure but the baseline model or baseline building it's a typical building according to a climatic zone. This building is defined with all the typical systems (ASHRAE 90.1). You must to model this baseline building and compare with your building (proposed) and you will have a gain, this gain will give you LEED points.
> I don"t know if I was clear.
> Don't hesitate.
> Oscar HERNANDEZPHD Candidate
>
> To: energyplus_support@xxxxxxxxxxxxxxx
> From: yli006@...
> Date: Wed, 23 Nov 2011 16:23:44 -0500
> Subject: RE: [EnergyPlus_Support] Question on Multiple zones per floors
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> ASHRAE 90.1 appendix G
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> This is a guide line, when you do not know what to do.
> When you have an actual case, the guilde line need not apply.
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> If you have many details in your actual plan and is not shown, then appling the guide line would result in less zones to simulate. The question is then will LEED certificates prepared in this way be acceptable.
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> I am not interested in generating LEED certificate.
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> Because LEED is interested in typical and averaged annual energy charges which is maialy occupancy and weather dependent. Therefore, they have their guide lines. If cost of gas per heat unit is less, a gas boiler should be used. Eplus will give you that, but it does not reduce the energy consumption.
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> That is why I said, high rise is by default not energy efficient.
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> One storey residential building does not need cooling in Summer, excep for special cases.
> Hood for oven, duct vent for dryer, attic ventilation, etc.
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> I still do not know what is meant by "a base line model". The multiple five zone model?
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> Dr. Li
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> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> From: sanphawat@...
> Date: Wed, 23 Nov 2011 12:53:19 -0800
> Subject: [EnergyPlus_Support] Question on Multiple zones per floors
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> Hi
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> I have attached my question and image for better discussion on multiple zone per floor. I really appreciate all thought.
> I am doing a research on building
> typologies to compare energy demand, embodies carbon, water, etc. from Super-tall building, high-rise, mid-rise, low-rise, to single home family in the same amount of units. I am using OpenStudio for interface and run EnergyPlus for energy simulation. I would like to set the best base line medelling strategy which will
> effect to all building typologies energy performance.
> ASHRAE 90.1 appendix G. has described on perimeter spaces should locate within 5 meter (15 feet). but in real building the lease space can be more than 5 meter. There are corridor and service core which both are different conditions and schedules. How could we possibly model just 5 zone per floor?
> Sanphawat
>
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