2. 2
Abstract
In general, the decision of a client is strongly dependent on both the initial cost
and running cost. For this reason, knowing utility rates for energy sources
before designing is very important. The aim of the project is to obtain a
suitable HVAC system with the best performance for a house located in Beirut.
By the best performance we mean a system with the lowest cost and the
highest efficiency. This will be achieved by optimizing the use of energy in the
house. Simulations on eQuest software will be done to find the results of all
sources of energy consumption in the baseline design. Then, modifications on
system components will be done to reduce energy consumption and save
money.
4. 4
List of Figures
Figure 1: Floor Plan ...................................................................................................................6
Figure 2: Map Footprint.............................................................................................................8
Figure 3: 3D Geometry of the House.........................................................................................9
Figure 4: Annual Utility Bills with VVT System....................................................................16
Figure 5: Annual Utility Bills with 7 HVAC Systems ............................................................16
Figure 6: Annual Utility Bills with Different HVAC Systems and Conditions ............ 1Error!
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List of Tables
Table 1: Zone Area (ft2) ............................................................................................................6
Table 2: Floor Equipment Rating ..............................................................................................7
Table 3: Cooking load..............................................................................................................10
Table 4: Refrigeration load......................................................................................................10
Table 5: Utility rates ................................................................................................................18
Table 6: Economy analysis without accumulation ..................................................................18
Table 7: Economy analysis with accumulation .......................................................................19
5. 5
Introduction
Nowadays, numerical solvers are widely used in energy systems design. They
provide fast simulations that govern accurate information about the system
capacity and costs needed to heat and cool a specific volume.
The following report represents a case study of a house to study its energy and
economic performance under existing conditions.
eQuest, based on the DOE‐II engine, is a tool used in this project in order to
analyze the heat and cooling needs for a one floor residence located in Beirut.
The building energy consumption is simulated for different design parameters
(i.e. insulation, roof and wall thickness, glazing, lighting system, and shading)
and the annual energy consumption report are generated and analyzed.
Many interrelated parameters affect energy consumption in a building. Here
comes the importance of modelling the buildings’ energy systems. It is a way
to know how passive I should design the building and to compromise between
passive and conventional systems to meet the minimal costs and energy
consumption.
Objectives
The main objective of the project is to optimize the use of energy for a
residential house in Beirut, Lebanon. The main issue regarding the increase in
the consumption of the electricity in our houses is because of the HVAC system
installed.
Using eQuest software, we will simulate the results of the base case we have
including the HVAC system, the heating system, the incandescent lighting and
the walls and roofs without any insulation in addition to the single glazing
doors and windows.
After that, different ECMs will be investigated and compared to the base case
to check which parameter has the most impact on the house we have. This
change in energy consumption will be directly reflected by a change in
electrical and gas consumption leading to change in the cost.
7. 7
Different Zone Equipment
Table 2: Floor Equipment Rating
Zone Equipment Type Quantity Rating
Salon
TV Samsung 1 100W
Electric Heater (4 Rows) Warm-lite 1 1500 W
Phone Panasonic 1 0.5 A
Vacuum Cleaner Hoover 1 1600 W
Lamps Fluorescent 15 40 W
Fan Dalco 1 60 W
AC Samsung 1 1 ton (3510W)
Master Bedroom
Lamps Incandescent 2 100 W
Laptop Lenovo 1 90 W
Iron Machine Philips 1 2630 W
Phone Charger Samsung 1 0.6 A
Fan Dalco 1 60 W
Bedroom
Lamps Incandescent 2 200 W
Fan Dalco 1 60 W
Modem T-link 1 0.3 A
Phone Charger Samsung 1 0.6 A
Laptop Toshiba 1 1.5 A
Corridor + Entrance
Lamps Fluorescent 3 40 W
Lamps Incandescent 1 100 W
Kitchen
Refrigerator Samsung 1 0.9 A
Microwave Samsung 1 700 W
Lamps Fluorescent 2 40 W
Washing Machine Samsung 1 500 W
Each Bathroom
Lamps Fluorescent 1 40 W
Exhaust Fan V-Guard 1 40 W
9. 9
Proposed Design of the Base Case
After dividing the plan into several areas, we need to design the walls, roof,
and the floor that will be composed of a single concrete layer without any
insulation.
Regarding the windows and transparent doors, we will be using clear glass
without adding any fins or overhangs for the windows. While the opaque doors
that we have, they will be composed of steel polyurethane sandwich.
Finally, after selecting all the required inputs, we will obtain the geometry as in
the following figure (figure 3).
Geometry of the Plan
Figure 3: 3D Geometry of the House
16. 16
Energy Efficiency Studies with VVT System
Figure 4: Annual Utility Bills with VVT System
According to figure 4, the grey color reflects the electric rate while the blue
one reflects the gas rate. The obvious thing is that the highest annual utility
bills was in the base case scenario which is 1500$. After implementing all the
previous alternatives to our base case accumulatively, the annual utility bills
decreased from 1500$ to 940$. This means that our annual utility bills were
decreased by 37.5%.
But we have stated before that not only the alternatives will be changed but
also different HVAC systems will be implemented instead of the VVT heat
pump system and check how the annual utility bills are varying with different
HVAC system.
Figure 5: Annual Utility Bills with 7 HVAC Systems
18. 18
Table 5: Utility rates
Utility rates of electricity
in Lebanon
Electricity
rates($/Kwh)
Utility rates of gas in
Lebanon
LPG cost
Government 0.053 $/cylinder 9.74
Subscription 0.16 $/gallon 1.5362461
Average 0.088666667 $/therm 1.09731864
By applying measure to the baseline each improvement is studied alone, but if
we apply measure in accumulative way, initial costs, savings, and profit is
calculated in accumulated way also. In table (6), each improvement is studied
alone over both twenty‐five years and fifty years. It can be analysed from the
table that an appropriate improvement is the one done on the roof. It has a
very low payback period and a very high profit incoming.
Table 6: Economy analysis without accumulation
Improvement
Initial
Cost ($)
Savings per
year ($)
Payback
Period
(years)
Profit in the
coming 25
years ($)
Profit in the
coming 50
years ($)
Roof 500 276 1.8 6400 13300
External Wall 350 16 21.9 50 450
Ground floor 425 18 23.6 25 475
Window Glass Type 500 66 7.6 1150 2800
Window External Shading 95 4 23.8 5 105
Domestic hot water 0 113 0.0 2825 5650
Lightning Power 50 41 1.2 975 2000
As predicted, the accumulated initial cost will increase and the accumulated
profit incoming will increase. All improvements will have a payback period of
four years which is very acceptable for seven improvements. The profit after
twenty five years is a high number which deserves going into with these
modifications.
19. 19
Table 7: Economy analysis with accumulation
Improvement
Accumulated
Initial Cost ($)
Accumulated
savings per year
($)
Payback
Period
(years)
Profit in
the coming
25 years
($)
Profit in
the coming
50 years
($)
Roof 500 276 1.81 6400 13300
External Wall 850 299 2.84 6625 14100
Ground floor 1275 323 3.95 6800 14875
Window Glass Type 1775 391 4.54 8000 17775
Window External Shading 1875 395 4.75 8000 17875
Domestic hot water 1875 507 3.70 10800 23475
Lightning Power 1925 555 3.47 11950 25825
Comparing Different HVAC Systems
After comparing the utility bills between the 7 HVAC systems, we realized that
the chilled water has lower utility bills compared to the Dx systems when
improvements occurs. This happens because the boilers are running on gas
instead of electricity, and in our case, which is Lebanon the gas rate is lower
than the electric rate as discussed before in Table 5.
As a result, the Dx systems was restudied again but instead of running the heat
pumps with electricity, we will be using gas. The results will be compared with
the previous results of the chilled water system in the following figure:
Figure 6: Annual Utility Bills with Different HVAC Systems and Conditions
