Water Services: HVAC Systems and Water Supply Paper Example

Buildings with HVAC systems and water supply is among the biggest international structures with a high demand for several building designs. The city has in the recent years scored high in terms of world cities with the most diverse infrastructural constructions. The city has a wide variety of buildings ranging from residential to commercial. Despite the rapid increase of building constructions, key considerations such as the need for sustainable and comfortable buildings designs should be looked in to. Engineers argue that the development and evolution of modern intelligent systems and buildings can be realized to the standard requirements(Chwieduk 2013).

Is your time best spent reading someone else’s essay? Get a 100% original essay FROM A CERTIFIED WRITER!

Save 25%

The supply of both hot and cold water in the building uses electricity and heating exchanger. The hot water has red pipe while the cold water has blue pipe. The cold water is not passed thought the heating element. The cold water is heated in the heat exchanger to raise the temperature. The heating element has thermostat which controls the temperature of water. The maximum and minimum temperature is set to ensure that the water has the correct range of temperature. In case, there is an overflow of water, the tank has overflow valve which controls the discharge of water. The rate in which the cold and hot water is consumed dictates the power consumption in the heating system.

Some of the heaters are designed to use solar instead of mains electricity. The solar heaters use heat from the sun hence its cheap and environmentally friendly. The heater has coil of copper tubes to increase the surface area for heat absorption. The water flows through the coils and gains heat. The solar heat exchanger is used in hot areas. During the night, the water is directed to the heat exchanger which uses electricity for heating.

Solar collectors are installed outside dwelling (roof/walls). Portable water is directly sent into the collector. The system uses integrated collector storage (ICS). Heating water this way is more efficient than using heat exchangers. There are many different classifications of cooling devices. The choice of the cooling device in this project was classified on the basis of functionality. The functionality heat transfer equipment is divided as outlined below:

• In the design of the cooling device, the basic cooling device equation was utilized;
• In this heat exchange design, a recuperative type of cooling device is used that has a combination of cross flow and a counter current flow.

The material selected for the cooling device is copper due to the following properties:

• Good conductor of heat. The metal should absorb maximum amount of radiant heat. Copper is the best material.
• The heating element should be non-corrosive and have high melting point.The only other material similar in resistance to corrosion is stainless steel but its thermal conductivity is 30 times worse than that of copper.

It allows heat to pass through it quickly-it is used in many applications where quick heat transfer is important as in the case of this project

Definitions in U;

C= heat transfer coefficient of copper=259

f= inlet temperature of water correction factor=1.0

m= copper material correction factor=0.97

cl= cleanliness factor of the copper material=0.85

v= velocity through cooling device tubes=7ft/s

U=259

p= 564:99Btu/ft2hR

The total surface area of the cooling device was calculated from;

Q: = 150kJ=s_1Btu=h

0:000293 = 511945:39Btu=h

A = 511945:39

564:98_38:95 = 23:26ft2

Calculation of the total number of tubes of the cooling device required;

Obtained by first calculating the mass flow rate of water in tubes.

Conversion of water flow rate to gallons per minute (gpm) gives

mw = 14627:01lb=h

500 = 29:25gpm

Calculation of the total number of tubes(n)

n =mw(gpm)

velocity in ft=s _ gpm@1ft velocity=29:25gpm

The total number of tubes was approximated to be 2

Area calculation of each tube

Area of each tube=11:63ft2

In selecting the materials to be used in the design, several factors were considered. These factors were outlined below

(i) Availability of the material.

(ii) Cost of the material.

(iii) Appropriateness of the material.

(iv) Machinability of the material.

(v) Properties of the material.

The Electricity Measurements

Electricity meters are used to measure electricity power usage by the house holders, the load power factor and the particular time when the electric current was utilized. This enables multi-rate metering. The measurements rely on several sensor technologies which are the equivalent of phase's number shown in the electrical system (Chudley 2016). The consumers use a single phase meters while the industries and the commercial consumers majorly use the multiphase meters(Chudley 2016). These multiphase meters are distributed from the mains although they need another supply so as to continue functioning in case a disruption or a disconnection of the service conditions occurs. The figure below shows the layout of the hot and cold water supply.

Gas and water meters are mainly battery powered. The micro controllers (MCU) which are joined to the sensor in the meter, the communication and the display blocks are also battery powered. All these systems use meters to calibrate the number of times a single unit of a fluid passes through the meter. A rotating shaft or a magnet is used to get the volume of thicker fluids. Each revolution is changed to an electric signal that is stored by MCU

The actual fabrication of this design should use a serpentine shaped heat exchanger instead of the straight tube type as this will achieve both efficient heat exchange due to the large surface area and also occupy minimal volume due to the coiled tube shapes. Theflow rate controller be used instead of the ball valve to enable automatic flow rate control of the water flow as dictated by consumption other than manual control of water flow. The acquisition of all fabrication materials and other project components should be done early before the commencement of the fabrication period.

The use of smart meters facilitates bidirectional communication in meter and the central system. Smart meters differ with the energy monitors used at home in the sense that they store data which is used for remote reporting. This metering system forms an improved device referred to as AMI (advanced metering infrastructure). The AMI device is different from the AMR (automatic meter reading) as it allows bidirectional communication between the smart meter and the central system. This communication is enabled by the use of fixed wires or wireless connection. The wireless communication is more expensive as it involves the use of cellular communications.

References

Chudley, R. and Greeno, R., 2016. Building construction handbook. Routledge.

Chwieduk, D., 2013. Towards sustainable-energy buildings. Applied energy, 76(1-3), pp.211-217.

Perez-Lombard, L., Ortiz, J., Coronel, J.F. and Maestre, I.R., 2011. A review of HVAC systems requirements in building energy regulations. Energy and buildings, 43(2-3), pp.255-268.