CENTRAL HEATING SYSTEM

And the members are:

Project leader:

Members:

Maaz Khan Reg # 234

Zavain Rehman Reg # 236H. M. immad tariq Reg # 233usman pervez Reg # 245awais iqbal Reg # 230

What is Central Heating? Central Heating is a heating system in which air

or water is heated at a central point and sent through the whole interior of a building via vents or pipes and radiators to provide warmth in multiple rooms or parts of a building.

  Central heat sources can be boilers for oil, gas,

biomass or solar heating systems. Depending on the size of the building and available energy sources, a central heating solution might have multiple shapes. 

How does Central Heating work? In one-family houses a boiler is often installed and

fuelled by fossils such as oil or gas, in areas where district heating is not available. Additional renewable energy sources could be utilized, such as solar heating or heat pumps.

  In multi-family houses the heat produced centrally

in the building is typically distributed to apartments through circulation- and riser pipes. Another solution is to produce domestic hot water locally, while maintaining heat supply through pipes.

Central heating system can be easily install by knowing about following facts:

Heat Load Calculation Boiler selection Radiator Selection Insulation of walls/Roof/Boiler and

Connecting pipes accessories

Heat Load

What Is Heat Load? Heat load (including heat loss, or heat gain) is the term for the

amount of heating (heat loss) or cooling (heat gain) needed to maintain desired temperature and humidity in controlled air (e.g., in a structure). Regardless of how well-insulated and sealed a building is, buildings gain heat from warm air or sunlight or lose heat to cold air and by radiation. Engineers use heat load calculations to determine the HVAC needs of the space being cooled or heated. 

In simplest terms: it is the sum of {the Area of walls, windows, roof or doors x estimated heat transfer coefficients of each (related to "r" values)x estimated temperature differences inside to outside} + any unusual loads 

Factor which effecting comfort in winter1. TEMPERATURE DIFFERENCE

2. WIND

3. RADIATION

How to reduce heat load.

By using insulation on wall, roof and floor.

By using double glazed windows. By using using material having low

value of thermal conductivity.

INSULATION

Reducing the heat load can save

energy and cut your running costs. It can also reduce the capital cost of a system.

R(brick) per inch

R (gypsum) per 5/8 inch

R(Cellulose) per inch

0.2

0.45

3

Formula use to calculate the heat load Q= A* U * ∆ T

Where

Q = Total hourly rate of heat loss through walls, roof, glass, etc in Btu/hr

A= Net area of walls, roof, ceiling, floor, or glass in ft sq.

U = Overall heat-transfer coefficient of walls, roof, ceiling, floor, or glass in Btu/hr ft sq F

Ti = Inside design temperature in °F.

To = Outside design temperature in °F .

Heat loads of the Apartments is equal to

Heat load across wall + Across Windows+ Across Roof Ceiling + Across Floor

Apartment

Apartment # 1

Apartment# 2

Apartment #3

Apartment # 4

Bedroom #1 (BTU/hr)

2627 3040.7 3040.7 3040.7

Bedroom #2 (BTU/hr)

2991.68 3383.7 3383.7 3383.7

TV RoomBTU/hr)

3981 2580 2580 2580

Hall(BTU/hr)

_

3209.47 3209.47 3209.47

Total 9600 12213.87 12213.87 12213.87

Boiler

A fire-tube boiler is a type of boiler in which hot gases from a fire pass through one or more tubes running through a sealed container of water. The heat of the gases is transferred through the walls of the tubes by thermal conduction, heating the water and ultimately creating steam.

Fire tube boiler

Main parts •Combustion chamber•Burner •Heat exchanger•Controls•enclosure

Why we use fire tube boiler?

More efficient combustion space allowed

Specification Vertical Fire Tube Boiler

Efficiency Medium

Floor Space Required Very Low

Maintenance Low

Initial Cost Low

Pressure Range 10 psi

Typical Applications Heating System

Temperature Up to 240 F

Boiler Specification

Volume of Boiler = 0.08 cubic meter Rate of Heat transfer = 15000 BTU/hr Steam temperature = 115 ° C Steam Pressure = 1.7 bar Total Volume Of System = 0.27 cubic m Mass Of Water = 2.5 Kg

Accessories Required For a Steam Boiler Low Water Cut Off senses water level in

a steam boiler it will stop burner when water level falls below a safe level.

A Water Column with a gauge glass when mounted on the side of the steam boiler allows the operator to see water level.

A Pressure Gauge and Thermometer, mounted or near the boiler outlet to check the performance.

Vent is use for the exhaust of fuel gases.

Safety Relief Valve: A Safety

Relief Valve opens if boiler pressure is excessive.

Thermostat: A Thermostat is a component of a control

system which senses the temperature of a system so that the system's temperature is maintained near a desired set point

A room thermostat constantly measures the air temperature of a space and can be set to whatever temperature you like. This prevents your home getting warmer than it needs to be.

When the temperature falls below the setting, it switches on the central heating. Once the room reaches the set temperature, the thermostat switches the heating off.

Combustion energy

Flame thermal power (thermal load) Mixture composition, gas velocity, heat of

combustion of a fuel

Heat of combustion higher heating value (HHV) (or higher calorific

value)

lower heating value (LHV) (or lower calorific value)

Fuel HHV MJ/kg LHV MJ/kg

Methane 55.5 50

Fuel + oxidizer products + energyCombustion is an exothermic reaction between fuel and oxidizer.

we are using natural gas

BENEFITS ARE: Natural gas is convenient. The energy source is piped directly to the

customer's facility through the safe, efficient pipeline system. There's no need to store oil on site in tanks, or schedule oil deliveries.

There is an abundant supply of domestic natural gas. Over half of the oil used in this country is imported. The price and supply of oil is susceptible to international events.

Natural gas is reliable. The pipeline system can't be easily damaged by weather or affected by weather conditions. In contrast, oil must be trucked to the customer's location, and truck deliveries are susceptible to weather conditions.

Natural gas is the cleanest burning fossil fuel. Because the combustion process for natural gas is almost perfect, very few byproducts are emitted into the atmosphere as pollutants.

PIPES

PIPES:There are many ways connecting pipes some of them are: Series Loop One pipe main etc.

We are using here one pipe gravity return,

Copper tubing advantages Frictional resistance is less than steel resulting in the

possibility of smaller pump and less power consumption.

It is not subject to oxidizing and scaling

ONE PIPE SYSTEM: In a one-pipe, gravity-flow

system, each heating unit has a single pipe connection through which it receives steam and releases condensate at the same time.

All heating units and the end of the supply main are sufficiently above the boiler water line so that condensate flows back to the boiler by gravity.

APT # Length Diameter Volume

Ground Floor 95‘ 2.5” 6.83 cubic feet

First Floor 105’ 2.5” 6.9 cubic feet

Steam mains

RADIATOR

What is radiator?

Basically radiator is a heat exchanging device. Usually it contains hot water or steam (depending on the situation /use)

The type of radiator mentioned above is used for the heating of room and lodges etc.

We used steam for the purpose of heating the rooms, lodges, halls etc.

It is the best device known for heating the rooms and halls etc. It is more efficient way of heating and transferring heat to the other system.