ASHRAE Journal - August 2019 - 34

TECHNICAL FEATURE

were obtained by simulating the
hotel building data over a period of
one year (8,760 hours). The hotel
considered in this study is located in
Doha Port, Qatar and has a built-up
area (BUA) of more or less 34,500 m2
(371,355 ft2).
The hot season in Doha lasts for 4.4
months, from May 11 to September
24, with an average daily high temperature above 100°F (37.8°C). The
hottest day of the year is July 11, with
an average high of 107°F (41.6°C)
and low of 88°F (31.1°C). The cool
season lasts for 3.1 months, from
December 4 to March 8, with an
average daily high temperature
below 78°F (25.5°C). The coldest day
of the year is January 25, with an
average low of 57°F (13.9°C) and high
of 71°F (21.7°C).9 Subsequently, the
following was determined.

FIGURE 4 Flowchart showing sequences to calculate the power and fuel consumption.

Outdoor Climate Data
DHW Design Conditions

Heat Load
Cooling Load
Increase Temperature
Determine:
Chiller Only COP
Recovery Chiller COP
Heat/Cold Ration

Increase Capacity

Determine:
Ideal Heat Recovery
Ideal Cooling from Recovery Chiller
Ideal Boiler Delivery
Ideal Cooling from Chiller Only
Determine:
Heat Recovery Capacity
Cooling from Recovery Chiller
Boiler Capacity
Chiller Only Capacity

Sensitivity
Recovery Chiller
Capacity
No

Maximum Heat Recovery
Capacity Reached
Yes
Maximum Hot Water
Delivery Reached

Heat and Cooling Demands Estimation

Sensitivity
Hot Water Temperature
Leaving Recovery Chiller

Yes

Cooling Load (kW)

Determine:
The total cooling demand comPower Consumption
LPG Consumption
prises the estimated cooling load for
the hotel. Figure 5 depicts the cooling
load demand for the hotel year-round.
FIGURE 5 Annual hourly cooling load profile.
The peak cooling load reached 1,754 tons
7,000
(6,167 kW) in August, and the minimum
6,000
cooling load is around 154 tons (541 kW).
5,000
Cooling is needed all year, even in win4,000
ter when the outside temperature drops
3,000
below 59°F (15°C), due to internal heat
2,000
gains. The annual cooling energy required
1,000
to cool the hotel is 23,400 MWh (the
equivalent of 3,797 equivalent full load
0
0
1,000 2,000 3,000
4,000 5,000
6,000
7,000
8,000 9,000
hours [EFLH]).
Time (Hours)
The total heat demand comprises the
estimated space heating, pool heating,
fresh air heating and preheating DHW load of the
heating is required all year except for the summer with
hotel. Figure 6 depicts the heat load during the year that
an annual demand of approximately 510 MWh.
includes space heating, fresh air heating, pool heating
The heat required for domestic hot water producand domestic hot water heating.
tion is required year-round with an annual demand
The heat required for space heating is concentrated
of approximately 6,431 MWh and constitutes about
between November and March, with an annual demand 89.7% of the annual heat required. The annual heat
of approximately 22.8 MWh. The heat required for pool
required for space heating, fresh air heating and pool
34

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