Thank you  Mr Jan, I am evaluating the national program of energy efficiency  and they announced that 

Thermal insulation building of 100.000 apartments per year of an area of 10.000 m2 using double glazing. The energy saving is around 25 million TEO over 30 years (lifetime of a home). 

I just want to know how they obtain this value (energy saving is around 25 million TEO ) and how I can check it ?

My best Mr Jan 

Thank you for your reply Mr Jan, it's in Algeria (North of Africa) where thermal solar weather is very hot during the summer. The demand for electric power increase in summer period due to the high temperature especially during the month of July and the first fortnight of August and this is due to use of air conditioning. Our building don't use the thermal insulation building at all. So the new program target this part to reduce the energy consumption. 

Thank you 

Hi Haddad,

I would recommend that you use an energy simulation software to evaluate the overall effect of insulation measures on a buildings energy consumption.  I would recommend simulating the building using something like Design Builder (which is driven by the proven Energy+ from the DOE) to evaluate and quantify the effect of the options.  I do have several papers to the respect available on my profile.

Let me know if I can be of further help.

Best

Alex

Thank you very much Mr Alex

In hot countries, thermal insulation should always be combined with solar protections, thermal inertia and adequate ventilation to get appreciable savings. The saving resulting of moving from single glazing to double (and IR coated?) glazing depends not only on the climate, but also on the type of building use (e.g. dwelling or office), on the orientation of the windows, and once again on their shading, on the building thermal mass and on the natural cooling by night ventilation.  Therefore, as already saiod, dynamic simulations should be used to estimate the savings resulting form one measure. The rough figures announced in the national program of energy efficiency are certainly very approximate.

Indeed, in some cases (e.g. a conditionned building which you cannot ventilate at night and that has no solar protections), a non insulated building may use less cooling than an insulated one, because the internal and solar gains can be evacuated through glazing and walls during the cold periods!  I must tell anyway that I dohn't recommend this kind of building, since good design includes solar protection, thermal mass, ventilation strategy and thermal insulation.

Whin the frame of a collaboration programme, a book was written on the way to design comfortable and energy-efficient buildign in composite and hot-dry Indian climates. There are some examples of saving amounts in it. More information is in the attached file, and you may download the full handbook from the attached link.

About windows role

You already received useful helps. The use of a powerful and already abundantly tested software is THE solution, of course. Yet there are many aspects that can be considered beforehand which can inspire the analysis of the results obtained from the software and also can contribute to the pre-assessment of the impact of the results.

And, in fact, at the end, the impact of the windows on the energy use for comfort may or may not be that big. One thing is the Physics problem approached in abstract or for generic climatic conditions which results can be obtained already from the literature for similar regions/climates, another problem is an actual specific case where the windows area represent, maybe, around 10% of the façades and can or cannot have a wooden or other protection at night making their heat losses less expressive than it usually appears relatively to the other heat losses caused by other envelope components such as the roof and the ventilation rate. So, let’s highlight a few points just taken form my experience as a resident in the Mediterranean Area:

What are the ranges of temperatures outside? Are you considering the cooling or the heating case or both? Are the walls already properly insulated or not? What about the use of the thermal mass as a moderator of the extreme indoor temperatures?  And what is the role of windows orientation and exterior shading? Are you considering natural ventilation through windows? What are the accepted indoor air temperatures for the thermal comfort of the occupants?  Are you familiar with the ‘adaptive comfort’ concept, the one that fits better the climates that don’t have simultaneous high temperature and relative humidity?  

Being in Algeria, I believe that some of the considerations I made above are for sure quite relevant. You need to know which tools are available, of course, and you may use them for some cases if you by political reasons need to have an overall figure regarding the savings concerned by using double glazed windows. But I would dare to say that such figures may certainly be useful as an indicator, but you must bear in mind that many windows might not justify the investment while other changes in the envelope are not be undertaken in parallel or beforehand. 

May I add an additional point on building energy efficiency in cities in warm climates

Energy, mostly electric, used for articifiual cooling  ends in heat leaving the cooled building. That heat increases the urban heat island effect, thus increasing, in a vicious circle, the need for artifical cooling and lowering the COP of the chiller. Therefore, the positive effect of any measure that improves the building energy efficiency may be underestimated if the global effect of the city is not taken into account. 

Thank you very much for all your useful comments Mr Roulet and Mr Fernandes.

The most buildings in Algeria have a poor indoor climate. They are too hot during the summer and too cold in the winter. The insulation building will be supposed using double glazing for a service life-time of 30 years for characteristics below:

 Thermal insulation building of 100.000 apartments per year of an area of 10.000 m2 using double glazing.

As for the solar water heating collector 

 Diffusion of solar water heating with 100000 SWH collectors per year. The total area is around 4.000 m2 of individual solar water heater and 3.000 m2 of collective water heater.

My work consistes to analyze the different benefits of energy efficiency program for Algeria by 2030 as final energy and electricity saved CO2 emissions reduction as well as offer new job.

Firsly I want juste measure the energy saved by apllieng this program and after that I will suggest other solution to improve the energy efficiency in Algeria by 2030.

The program of energy efficiency in India is very interrsting experience thank you Mr Roulet for the documents

Mr Fernandes I am now in university of Minho of Guimaraes and I hope if I can contact you in Porto for more assistant

Thank you for all your help

Brahim

Dear Brahim

I will insist on the fact that, in warm and hot countries, energy saving (and improvement of comfort) does not depend on thermal insulation only, but also on solar protection, thermal inertia and adequate ventilation.  These four components for a comfortable and energy efficient building interact each other,  and the benefits of one of them cannot be considered or assessed independantly. 

Could you provide me a document on the energy efficiency program for Algeria by 2030?

Thank you Mr Roulet,

Please find below the link of the program 

https://www.cder.dz/spip.php?article1749

Thank you for the information

I have seen that, for buildings, apart economic lamps and efficient equipment and devices, the program addresses thermal insulation only. This is indeed a good point, but only one good point among four. You may recommend to promote integral design of buildings, looking for improved natural comfort and energy efficiency by taking advantage of passive design measures, which include thermal insulation and inertia, solar protections, and adequate airing.

Within a cooperation program, we developed design guidelines for buildings in hot-dry climates. I attach the link to these. Since I am sure you read French, I aléso attach a file on passive cooling.

Thank you very much Mr Roulet,  and I really appreciate all the help you gave me.  I will add all your suggestions in my work. 

Thank for all your help 

Dear Haddad,

During my PhD, I developed a Facade Refurbishment toolbox, where I calculated how much energy can be saved by renovating residential buildings with different measures, including adding insulation and replacing windows. I generated data for pre-calculated models by means of dynamic simulation using DesignBuilder. They are meant to support decision making in the early design phase. My focus was on the climate in central/North Europe, which is different than in your case, but maybe you can still find interesting the method or the results.

You can read more and see the data in my thesis, available here:

http://abe.tudelft.nl/index.php/faculty-architecture/article/view/konstantiou

and a summarised version of the approach here:

DOI: 10.3390/buildings5041221

Hope this helps. Feel free to contact me if you want to discuss further.

Thank you very much Konstantinou for your help 

The first question is what the purpose of your study is.

1. to investigate a concrete location in Algeria

2. to run a general research

There are two options for calculation:

1. stationary calculation: there are tens of computer software tools on the market:

In your case I would look at: first in French and second in German ones but most likely some tool(s) are used in practice in your country.

you can start here:

http://www.rehva.eu/publications-and-resources/rehva-journal/2012/032012/energy-performance-requirements-for-buildings-in-europe.html

Energy performance requirements for buildings in Europe

Marina Economidou

Senior Energy Efficiency Expert, MEng PhD

Buildings Performance Institute Europe

Rue de Stassart 48, 1050 Brussels, Belgium

2. dynamic calculation: for advanced studies, EnergyPlus (more users friendly) and Trnsys (pretentious), both USA.

But for the beginning I would start with the study of solutions used in the local vernacular bioclimatically oriented buildings and investigate new solutions on their patterns upgraded with new cyber-physical systems which should not be a problem for you since you are working in UDES : Unité de Développement des Equipements Solaires.

Dear Ales

Good to read you! Long time no see. Yes, you are right about tools. Unfortunately the issue raised asks to go much beyond the availbility or not of the tools.As PLEA always taught! The issue is: What matters; really? Are the form/orientation/location of the windows as well as the type of walls/doors/roofs such that they may jeopardize the effort on the windows?  Having said that, when dealing with energy in buildings, we have to value systems, of which the building itself is the #1, and not exhacerbate the focus on parts that risk becoming from times to times kind of gadgets... That can be the case of windows, ventilation, heating, cooling, etc. 

Good Christams season and Happy New Year!

Thank you dear Ales, the objective of my work is to measure the energy save by according to national program of efficiency using thermal insulation for residence building in Algeria. We have all the data of about building materials using in this program. I am starting to use Energyplus and TRNsys to make simulation. But I still not understand how to simulate building in this software and also I am trying to solve the data weather issue.

Thank you very much

Brahim

Dear Brahim

If you intend to use TRNSYS, you may contact Dr. Naïma Fezzioui at the Bechar university ([email protected]). She is used to simulate buildings in Argeria with this software,m and has weather data for Algeria.

Ah great, Thank you very much dear Roulet 

You got good answers from our colegues, namely from Jean-Claude Roulet ,a friend of mine for over 40 years.

Trying to add something to what was written, I would say that buildings 'must try' to cope with the climate by themselves. Of course that is not only possible. But it is possible more often than the current literature and market tend to suggest. Having said that I would like to raise the concept of 'energy sufficiency' which means for comfort conditions in buildings,  that comfort must be obtained as much as possible thorough the design and construction themselves: insulation; orientation of windows, shadding; thermal inertia indoors...

Eduardo de Oliveira Fernandes

http://www.ursa.com/en-us/building-insulation/what-insulation-is/pages/thermal-insulation-and-energy-savings-tbd.aspx

https://pdfs.semanticscholar.org/d3a2/6a31ff2e5f58a6bff5973bd8e2060ef13238.pdf

Article A Study of Energy Saving in Building through Thermal Insulat...

Dear Hamit Can, excellent! Thanks a lot!

I will come back to you soon.

Eduardo

this file maybe to help you