The document discusses the design of a zero energy house in Ifrane, Morocco for a family of five. Key aspects of the design include: 1) Focusing on energy efficiency through high insulation, passive solar design principles like window placement and shading, and use of renewable energy sources. 2) Relying on a 2.83 kW photovoltaic array and solar water heating to meet the house's estimated annual energy needs of 3,500 kWh. 3) Selecting building materials based on factors like embodied energy, toxicity, and recyclability to minimize environmental impacts and ensure occupant health.

1. Zero Energy house
Thermodynamics
By Kawthar Khaloufi
Omar Fassi Fihri
Supervised by: Dr.Hassan Darhmaoui

2. Introduction:
Most of the time, we're too absorbed in modern life to realize that it is energy that makes
it all possible. Every home, business, and every government. Every major issue is underpinned
and established by energy. Which is why it is the most important issue of our time. We can
clearly see how important it is to every aspect of our lives and thus, as engineers we should be
able to improve the consumption of energy into a more efficient way.
The building sector is the largest consumer of energy in Morocco with the share of about
36% of the overall energy consumption of the country; therefore, Zero Energy house is one of
the designs that implement an energy efficiency strategy. A zero energy house refers to a house
with a net energy consumption of zero over a typical year. It implies that the energy demand for
heat and electrical power is reduced, and this reduced demand is met on an annual basis from
renewable energy supply.
Missionstatement
Our job in this project is to assist a family of five people in the design of their zero
energy house in the region of Ifrane, Morocco. The house consists of two floors with 120m^2
each with a large garden. The design of this ZEH carefully combines envelope efficiency,
efficient equipment, appliances and lighting, and passive and active solar features, including
photovoltaics (PV), while utilizing all the natural renewable energy sources the site had to offer
to reach the zero energy goal.
Missiongoals
Our goals for the construction of this zero energy house consists of seven important
objectives. Starting with (1)Energy efficiency & greenhouse gases by Minimising household
energy usage and maximising the use of renewable energy therefore reducing carbon dioxide and
other greenhouse gas emissions from energy generation. These initiatives also provide a hedge
against increasing energy costs. (2)Low embodied energy by reducing the embodied energy of
the house by using products and materials which require minimal energy during processing,
manufacture and transportation. (3) Water conservation our target is to Reduce water use
through low flow fittings and efficient appliances. This results in energy and resource efficiency
by minimising supply and waste water infrastructure requirements and reduced water storage

3. needs. Water efficiency results in a house with a greater ability to provide for its own water
needs and reduces the cost of water supply and waste water disposal (4) Health & comfort, one
of our main concern is to provide a healthy environment to our customers by Ensuring a
warm and dry house with good daylight and fresh air supply increasing the comfort, happiness
and health of occupants. This also has the potential to reduce medical costs and days off
work. (5) Waste minimization, Landfill waste can be reduced by using materials efficiently,
adopting recycling and reuse practises onsite and selecting construction materials that are
recycled and recyclable.(6) Low pollutant emissions, Pollutant emissions can be reduced
through the use low emission products and materials, stormwater management and
environmental management during construction and operation. These initiatives reduce the
impact on houses and environment in Ifrane. (7) Durability, Durable materials and products can
help to reduce maintenance and resource costs. It is important to assess durability based on life
cycle analysis.
Designof the house:
Location Ifrane, Morocco
House size(floor area in m^2) 120
Number of floors 2
Number of occupants 5
Number of bedrooms 3
Type of heating system Heat pump
Main heating fuel solar and geothermal energies
Others
We began the design by using the integrated design which is related specifically to
energy efficiency. In order to achieve significant levels of efficiency, and ultimately zero energy,
it required us to make an integration across all elements of the house including site, structure,
materials, systems, landscape, and occupants. It costs the family 18235.19 MAD per square
meter. Concerning the solar hot water, it extract the heat in the air outside of the unit and transfer
that heat to the water stored inside the heater; bringing the temperature up to 55 C -60C. These
units can effectively heat water even in very cold conditions as cold as -10C. In addition, The

4. design is very easy to install . we chose as well a PV system from Perlight Solar with a high
efficiency and reliability. The cell efficiency is up to 17.63% and a 25 years performance
warranty. The house was designed to be warm without the need for heating, which realises two main
benefits regarding the future financial and comfort of the occupants. By eliminating heating systems
and the need to operate, maintain, and replace them over the next 25 years makes passive heating a
cheaper option in the long-run. And Designing a house to be warm throughout without heating
eliminates the struggle from mechanical heating systems issues.
After choosing the heating and power systems of the building, we looked at the actual design of
the house in order to meet the requirements and goals we stated above. We came up with three
important considerations that need to be taken into account in the construction of the house for a
better efficiency. These are the following : 1) Solar access, 2) Natural ventilation and shading, 3)
Optimally sized performance glazed windows. The most appropriate side for both bedrooms and
the living room is the north side of the house as it will benefit them from warmer temperatures
and more daylight. This design will have a positive impact on energy efficiency, low embodied
energy, and occupant’s health. The majority of the glazing is on the north side of the house to
optimise daylight and solar gain, with glazing on the south side to reduce heat loss. Therefore; Heat
is retained in the house through both high-performance glazing and a double layer of insulation as
discussed in the material phase. The house has been located and orientated on the site to make the
most of the site-specific sun angles. The internal layout of rooms has also been planned around which
rooms need sun in the morning (kitchen), throughout the day (living areas), and evening (bedrooms).
Shading features are one of the systems that we recommended to the family in order to reduce
solar gain on summer days. Shading is important because it is directly related to reducing
temperature, improve comfort, and save energy. There are typical shading features that we can
use for a optimum temperature control on warm days : 1) The Overhangs, 2) Fins 3) Louvres 4)
Vegetation and 5) screens. It is known that during the summer the sun is most warming and
heat enters the most during the late afternoon in which the sun is positioned in the west, therefore
in our house design we will be keeping the glazing into a minimum in the west side of the house
to help reduce the solar gain however, the glazing will be maximized in the northern side for a
higher gain in heat during the winter as the trajectory of the sun in this period of the year shows
that it is most warming when it faces the house from the north. We have included both the
overhangs to reduce the amount of heat coming from the sun in the northern direction and corner

5. fins that will stop some heat to enter from the eastern and the western sides of the house for the
safety and comfort of the occupants during the whole year. We are also considering sliding
shades along the north elevation that can be extended, contracted, or moved as required, and
vegetative shading on the eastern elevation to help reduce low level sun during the summer
months; it will reduce air conditioning needs and heat loss from wind. The size and location of
the windows are also relevant to the fulfillment of the energy efficiency and health comfort
goals. When it came to the selection of location of the windows, it is better to put the windows
facing the west side of the house to allow more heat to enter the room. Also, we used the double
glazing which minimizes the heat loss through the windows and provides a good solar gain.
Fig1.South side of the house, showing reduced Fig 2. North side of the house, showing largerarea of glaz ing in
glazing area to reduce heat loss order to maximise solargain.
0
2
4
6
8
10
12
Solar acess Shading system Optimal sized
performance
glazed windows
Energy efficiency
low embodied energy
water conservation
health and comfort
waste minimisation
low pollutant emissions
durability

6. Structure of the Zero Energy House :
• The construction of a Z.E.H requires a special structure which is represented by what we
call "the envelope of the house " It is a very important and crucial consideration that needs to be
taken into account when building our house. It consists of the walls, the roofs, the floor, the
windows and the doors, the reason why these elements are important is because they can have a
huge impact on the energy performance of the house. The choice of insulated walls and high
performance windows will avoid us the need to heat the house during the majority of the time
during the year and therefore help us save the cost. Before studying each of the elements of the
structure it is important to keep in mind some consideration that we need to know before. It is
known that the building envelope separates the inside of the house from the outside, protecting
inhabitants from outside harming elements. After doing some research, we found out an
important result which says 1) that a building envelope that avoids heating or cooling gets us
30% towards the Zero Energy goal. This means that the heating and cooling of the house should
not be done by some electrical work but rather in a natural way based on the material used in the
walls as well as the windows to heat and cool the house depending on the outside temperature.
However, this can be done in areas where the climate is rather stable which means not too cold
and not too hot. This is not the case in Ifrane because of the fact that the climate is cold during
the whole year and reaches many times very low temperature below the 0°c. Ifrane holds the
record of the lowest temperature ever recorded in Africa which is -24°c and this is of concern to
us because it will not allow us to take into consideration the analysis we did at first as it is
mandatory for us to heat the house for the comfort and the well beg of the occupants. Second, we
need to keep in mind that a building envelope can't achieve high performance through products
and materials alone. Knowing that the heating will still be necessary because of the very cold
climate of Ifrane this does not exclude the fact that we can use some processes that will enable us
to cut the costs and thus to maximize the efficiency. One of the means that can permit us to do so
is the " passive solar design" refers to the use of the sun’s energy for the heating and cooling of
living spaces. In this approach, the building itself or some element of it takes advantage of
natural energy characteristics in materials and air created by exposure to the sun. Passive systems
are simple, have few moving parts, and require minimal maintenance and require no mechanical
systems. This is one of the most cost effective ways for the performance of a building and to be

7. able to use the passive solar gain we should 1) Face the windows towards the north, and design
their size to allow the right amount of passive solar energy into the house. 2) Place living areas
like the lounge, dining, and bedrooms on the warmest side of the house which is the north and
spaces less lived-in such as the kitchen and bathrooms on the south.3) Place the kitchen at an
eastern corner to take advantage of morning sun
Materials
As we mentioned in our goals for this project, we are very concerned with the
health of our customers as well as the environment for this reason we chose materials
based on life-cycle analysis to minimize environmental effects. Each product we chose
for the house is based on the type and volume of raw materials used in manufacturing;.
Two of the most visible examples of products that were chosen with this in mind were the
low-VOC (Volatile Organic Compounds ) paints throughout the house for the health and
comfort of the family as it is for pollutant emissions. We chose to use a selection of
waterborne paints from Resene which provide excellent protection and durability while
releasing a far lower level of VOCs per litre than solventborne paints. And the non-
treated cladding that is used on that exterior and within the entrance way and garage in order
to minimize toxicity on site due to the fact that it has a positive health impacts. Within the
walls we've also used products that minimise toxicity. We've installed non-PVC cabling
throughout the house, and for the pipework have used polypropylene pipes for water supply
and polyethylene pipes for water waste. The GreenStuf insulation is also bonded using heat
instead of chemicals.
Insulation is very important to reduce the amount of heat we need to
generate, and therefore save energy, along with the associated
pollutants and emissions. As we know the insulation properties of a
material can be expressed by its K-value, The k-value is the thermal conductivity of
a material, and so obviously, for insulation process we chose materials with the lower
value of K as well as Insulation that contains recycled material, it is safe to handle, and
can easily be recycled at end of life. It is also important that the insulation maintains its
thermal properties throughout it's life. All these Low impact thermal insulation have a

8. good impact on energy efficiency, family health, and low pollutants emissions. During
the process, we made sure we are using locally sourced products to minimize
transportation emissions and embodied energy, at the same time to provide good impact
on low pollutant emissions, low embodied energy, and energy efficiency.
Photovoltaic and solar water heating :
 Solar energy power:
This part of the design of the Zero Energy house is perhaps the most important one since it deals
with the sources of energy and its generation; as well as how these sources will be used in order
to cover the essential needs for the house and its occupants to live in comfort and for them to be
able to use all appliances that they need and benefit from the heating. Our goal for this project as
stated before is to build an energy efficient house and for that to take place, no source of energy
should be taken from other than Renewable energy sources because otherwise this won't make of
it efficient nor will it be " zero energy ". Thus, the main power sources we chose to use among
the Renewable energy sources are the Solar and the geothermal energies. Before starting to talk
about this we need to first of all know what is the total energy consumption of the house so that it
enables us to know the percentage of each energy source.
Appliances Energy Consumption Cost per year
2 TV SETs 1.32 KWh/day 24.1
Game consol 0.09Kwh/day 3.29
Refrigerator 4.32Kwh/day 157.70
Freezer 4.8kwh/day 175.22
Microwave 0.6kwh/day 21.90
Oven 2.4kwh/day 87.61
Stove 3 kwh/day 109.51
Dishwasher 1.08kwh/day 39.42
Clothes water 0.13kwh/day 4.56
Desktopcomputer 0.45kwh/day 16.43

9. 2 Laptops 0.72KWH/day 13.14
Printer 0.01kwh/day 0.29
Cordless phone 0.05/kwh/day 1.75
4 Cell phones 0.04/kwh/day 0.55
Iron 0.17Kwh/day 6.02
Vaccum cleaner 0.25Kwh/day 8.51
Hair dryer 0.25 kwh/day 9.2
Water cooker 0.26Kwh/day 9.64
Lawn mowner 0.2 9.5
Heatig system Eenergy consumption Cost per year
Space heater 7.50 Kwh/day 273.78
Air Conditioner 2 Kwh/day 73.01
Lighting Energy consumption Cost per year
Light bulbs 0.30kwh/day 10.95

10. From the the tables above we find the average energy consumption of a typical house is actually
in the surroundings of 12132.6 Kwh per year. Based on all the energy analysis we have made for
the typical house we expect that we will be using around 3500 kwh/a.
Photovoltaic size and selection :
The north side of the roof will be completely covered with solar, we expect the P.V array to
generate about 1250 Kwh/year for every killowatt peak installed. Thus, to meet our expected
energy usage of 3500 Kwh/a we need to install a 2.83 Kilowatt peak. We have taken into
consideration two technological options - amorphous thin film silicon and crystalline thin film
silicon. Even though they may not be the best solution or the most efficient but the choice here
was made based on the fact that a less efficiency will enable us to cover the whole area and
install 2.8 kwp hat we need in order to achieve the 3500 kwh that we need to use. If we were to
use a higher efficiency material in the solar panels it would only enabled us to use 2 .2 kwp
29%
17%
14%
13%
12%
4%
11%
Typical household energy consumption
breakdown
Heating
Cooling
water heating
Appliances
Lighting

11. The grid connection
We've also planned to install a grid-connected PV array. Rather than store energy onsite in
batteries, any energy that is not immediately used in the house is exported back to the electricity
grid. When there is insufficient energy generated by the PV array for the needs of the house,
energy is imported from the grid. This type of system is more cost effective both initially and
over time as no batteries are required for set-up or replacement. Also, by not storing batteries we
are avoiding toxic elements such as lead and acid on the property. Instead, with a grid-connected
system we effectively use the grid as our battery.
Solar Water energy ( Geothermal):
As we have shown before that in a typical house in Ifrane the energy consumption of water
heating is around 14% of the total energy demand. However, for the zero energy house since we
have used the passive solar design then takes care of a part of the heating and cooling of the
house so we would expect a rise in the percentage of the water heating in the energy use to rise to
30%.

12. Solar water heating technologies
There are two main types of solar hot water collector used for domestic hot water heating. We will
use a collector plate which is heated by the sun energy and to minimize the loss of this generated heat
we will insulate the collector.
There are three main factors influencing the efficiency of the collector:
1. How much solar energy falls on the collector plate,
2. How much of the solar energy that falls on the collector plate is absorbed and transferred to
the water rather than being re-radiated.
3. How much of the energy absorbed by the collector plate is lost back to the air.
we will be using the Evacuated tubes, because they can work in cloudy conditions even when the
pool temperature is higher than the outside temperature. Eight collectors, insulated and covered by
protective glass, are laid out next to one another to run the full length of the roof-line. The system
works by pumping water to the roof, where it is heated by solar energy captured by the collector
plates. Water is then returned to the hot water cylinder on the first floor of the house.
Water
Water usage has direct impacts on energy consumption within a home, which means it’s
closely linked to our Zero Energy goal. using the rainwater tank leads to cut the volumetric
component of water bill in half. Rainwater is collected from the roof via downpipes that feed into the
underground tank which is then used to flush toilets, wash clothes, and water the garden. We expect
the tank to meet around half of our water needs over the course of a typical year. Around half of the
average home’s water usage is in flushing toilets, watering gardens, and washing clothes5
. We’re
pouring drinking water down our toilets each time we flush them. Using rainwater for these purposes
means each installed tank reduces unnecessary water treatment. Using a rainwater tank requires a
pump to control distribution, and this provides an opportunity to install an efficient product to reduce
energy demand, helping us achieve our Zero Energy goal. The pump uses the minimum amount of
energy required. It also has an inbuilt stop function to stop operation on low demand and then restart
on demand ( Ex: CME booster pump).

13. 1. Rainwater pump 2. Rainwater tank installation
The area of a house that consumes the most water is showers, which typically account for
over a quarter of the average home’s use. To reduce that volume as much as possible we’ve installed
low-flow Kiri showerheads( EX: Methven brand) to ensure great showers with less water. We paid
attention to the Water of each product when deciding what to use in the house, which allowed us to
easily see how much water we could expect each product to consume. So an efficient low-flow Kiri
does not only save water but it also reduces the energy required to heat water. Because the Kiri is
using 40% less water it’s also using 40% less hot water, meaning 40% less water heating. Another
product that saves energy are the Tahi taps we’ve installed throughout the home. They have a twin-
lever mixing mechanism that separates the control of hot and cold water, meaning hot water is only
demanded when it is needed. This results in less hot water and, again, less energy used.
Water efficient products that reduce hot water heating have another benefit. Because we’re
heating our water using solar hot water panels, the lower the volume of hot water required, the
smaller the solar hot water system can be. In addition to that, water metering also assist in energy
conservation by allowing the family to monitor their high hot water usage

14. 1. Low-flow kiri showerhead 2. Tahi taps
Lighting:
As one of the components of the house that consumes energy, well thought-out lighting plays
an important part in helping us meet the Zero Energy goal. A house in Ifrane consumes around 12%
of its electricity in lightening. Zero Energy means we need to produce as much energy as we
consume, so cutting that 12% down as much as we can allows us to reduce the size of the solar
system on the roof. Therefore, the lighting design is a very important process that we took into
consideration from choosing the lamps to specifying the number and location of lights needed. It's
therefore important to consider lighting as part of the overall integrated design process, not just
something left until last.
Choosing a lighting product can make a huge difference in power bills saving. LED lights,
which stands for ‘Light Emitting Diode’ a semiconductor device that converts electricity into
light. LED lights are super energy efficient, using approximately 85% less energy
than incandescent bulb meaning significant savings on power bills.LED lighting contains no
mercury, they do not need replacing anywhere as often. This reduces the materials needed in
manufacturing replacement bulbs, and also reduces the volume of materials requiring disposal.
0
2
4
6
8
10
12
water metring rainwater
impact of water on the goals
energy efficiency low embodied energy water conservation
health and comfort waste minimisation low pollutant emissions
durability

15. Payback Period:
Conclusion:

16. Zero Net Energy buildings are a technically feasible method of reducing Morocco's
energy demand. The combination of demand side management with renewable energy sources
Provides a technically attractive way of constructing buildings with no demand on the
Utility grid. Viable renewable energy sources consist of photovoltaic cells, solar water
Heaters, and geothermal heat pumps. On the demand side, passive solar design
techniques reduce the energy demand of buildings. The use of high efficiency lighting
and appliances also contributes to energy efficiency. The fact that we were able to complete
the design and construction of the zero energy house and taking into consideration all of the
components including the comfort of the occupants and the essentials for living without
recourse to outside energy demonstrates that zero net energy is more than just a long term
vision. It is a current reality
References:

17. ASHRAE.(2001). ANSI/ASHRAE/IESNAStandard90.1-2001 EnergyStandard forBuildingsExceptLow-Rise
Residential.Atlanta,GA:AmericanSocietyof Heating,Refrigerating andAir-ConditioningEngineers.
Barley,C.D.;Deru,M.; Pless,S.;Torcellini,P.(2005).Procedure forMeasuringandReportingCommercial
BuildingEnergyPerformance.Technical ReportNREL/TP-550-38601. Golden,CO:National Renewable
EnergyLab www.nrel.gov/docs/fy06osti/38601.pdf
CEC. (2005). Time DependentValuation(TDV) EconomicsMethodology.www.energy.ca.gov/title24/
2005standards/archive/rulemaking/documents/tdv/.Sacramento,CA:CaliforniaEnergyCommission.
EIA.(2005). Annual EnergyReview2004. www.eia.doe.gov/emeu/aer/contents.html.Washington,DC:
U.S. Departmentof Energy,EnergyInformationAdministration
Mermoud,A.(1996). PVSYSTVersion3.3.User's Manual. Geneva,Switzerland: Universityof Geneva,
UniversityCenterforthe Studyof EnergyProblems.www.pvsyst.com/.LastaccessedSeptember2005.