Chapter Rule of Thumb Daikin s Method Compatibility Mode

FCB 20603HEATING & COOLING

LOAD

1FCB 20603 Heating & Cooling Load

COOLING LOAD

• PURPOSE OF DESIGN LOAD CALCULATIONSOutside weather conditions and the sun

combine to produce a cooling or heating load through the building envelope.

The load depends on :o The thermal characteristics of the walls, roof,

fenestrations (an opening in a surface of a structure), floor, interior building furnishings, and construction, and

o The driving force resulting from the difference between the outside conditions (including solar) and the inside conditions.


COOLING LOAD

• For example, the heat transferred through a roof depends on the temperature of the top surface of the roofing, the temperature of the inside surface of the ceiling, how these temperatures vary with time, and the energy storage characteristics of the roof construction.


COOLING LOAD

• The temperature of the outside surface depends on the ever-changing solar radiation absorbed by the surface.

• A similar analysis of the inside surface shows that the surface temperature depends on the amount of heat conducted from above and convection occurred to the inside air, the radiation exchange between the surface and room furnishings, and internal sources.


COOLING LOAD

• Therefore, the heat flow through the roof construction will not be constant.

• This same phenomenon occurs for all other surfaces subjected to radiation effects and variable temperature environments.


COOLING LOAD

• Under the conditions described above, the amount of insulation and the thermal mass of the roof, wall, or partition are critical in the heat transfer analysis.

• The heat transferred through transparent surfaces such as glass is more a function of the thermal radiation characteristics of the glass and less dependent on the thermal storage capacity of such materials due to very low mass and absorptance of the material.


COOLING LOAD

• The heat gain due to lights, people, and equipment is independent of the outdoor environment and is a function of occupancy and operating schedule.

• Again, radiation effects are involved, and the thermal storage characteristics of the space are important in estimating the cooling load.


COOLING LOAD

• Design load calculations provide the basic data for selecting an HVAC system and equipment and also provide the basic for sizing the associated ducts and piping.

• These data should be computed from times of peak load as well as partial load.

• Analysis and study of these conditions may then indicate possibilities for load reduction or other refinements of the system.


COOLING LOAD

• It is usually desirable to carry out extensive load calculations (several different hours of the day or all 24 hours) if the system is to be complex, such as a large variable air volume (VAV) system. Further, it may be necessary to make calculations for two or more months.

• On the other hand, a small building using unitary equipment may require load calculations for only the peak time of day.


Infiltration : When outdoor air enter a space through cracks on floors, walls, ceilings partition.10FCB 20603 Heating & Cooling Load

COOLING LOAD

RULE OF THUMB


22.95 590.55

95.15

22.95

9.45

292.00

752.00

137.85

Unit measurement :meter

Sale

Food CourtShop 1Office

Surau

Shop 2

Calculation :1. Sale

Area = ==

2. Shop1Area =

==

3. Shop2Area =

==

4. Food courtArea =

==

5. OfficeArea =

==

6. SurauArea =

==


COOLING LOAD


< calculation Cooling Load>28FCB 20603 Heating & Cooling

Load

We set below experiment at room temperature and room pressure. Which one will will become heavier after 3 hrs?

t = 0 Water + bottle = 200 grm ice + bottle = 200 grm

t = 3 hrs

Water + bottle = 200 grm Water + bottle + condesation = 200 + grm


Assuming below are 3 container place at room temperature and room pressure, which represent the vapor (gas), liquid and solid of water?

represent water molecules

represent water molecules speed 32FCB 20603 Heating & Cooling Load

Gas Liquid

Ice Liquid water

Solid

Water vapor

Assuming below are 3 container place at room temperature and room pressure, which represent the vapor (gas), liquid and solid of water?

represent water molecules

represent water molecules speed 33FCB 20603 Heating & Cooling Load

Assuming that the ice in the bottle is been heated, what can we say interm of the molecules and pressure and the density inside the bottle as time goes by?

t=0 t=10 t=20 34FCB 20603 Heating & Cooling Load

< calculation Cooling Load>

7.5

m

Example 1:

1.6m

x 2

.5m

Next Room

Window with blind

1.5m x 3 m

window

DoorDoor

window

window window window window

2nd Floor

Passage

N

Ceiling height : 3.0 m

• Find the cooling load of a double-storey house based on the following conditions.– Specifications of construction

• Building: Five-storey building• Outside wall: Medium construction• Window glass: Normal (6mm thickness) with blind• Floor: Concrete with linoleum (a type of strong material with a hardy shiny

surface, used for covering floor)• Ceiling: Only concrete• Lights: Fluorescent light (40W x 20)• Persons: 15 (working)• Area: Standard temperature area*** Adjoined upper and lower rooms are not cooled

18 m


COOLING LOAD• Example 2. Find the cooling load of a double-storey house based on the

following conditions.– Specifications of construction

• Building: Double-storey house• Outside wall: Light construction• Window glass: Normal (6mm thickness) with blind• Floor: Concrete with linoleum (a type of strong material with a hardy shiny

surface, used for covering floor)• Ceiling: Only concrete• Lights: Fluorescent light (60W x 17)• Persons: 7• Area: Standard temperature area• Roof: Light construction with ceiling


Ruang Tamu

Ruang makan

Dapur Utility

Bilik Mandi

Bilik tidur 2 Bilik tidur 3

Bilik Mandi

Ruang Tamu

Bilik tidur utama

Bilik Mandi

Balkoni

6096 mm 6096 mm

13715 mm

2133

6 m

m

1371

5 m

m

3000

mm

3000 mm

4300 mm

13715 mm

3000 mm

2000 mm

Ceiling Height = 3000mm< calculation Cooling Load>

N


Chapter Rule of Thumb Daikin s Method Compatibility Mode

Documents

Transcript of Chapter Rule of Thumb Daikin s Method Compatibility Mode