Mechanic Engineering Project Topics

Design of Water Supply (Cold and Hot) System of a Three Bedroom Bungalow With Adequate Pressure

Design of Water Supply (Cold and Hot) System of a Three Bedroom Bungalow With Adequate Pressure

Design of Water Supply (Cold and Hot) System of a Three Bedroom Bungalow With Adequate Pressure

Chapter One

Aim and Objectives

The aim of this research is to design a water supply system for a three bedroom bungalow to ensure adequate pressure. The specific objectives are to:

  1. Carry out the design analysis of the piping system
  2. determine the adequate flow pressure
  3. determine the flow rate at outlet
  4. determine the constant pressure range
  5. determine the pipe size
  6. determine the loading unit




As would be familiar from our residential settings, water in buildings is commonly used for cleaning, for personal hygiene, for heat transfer and for

Landscaping. Although water–consuming activities often remain similar, the sophistication of water infrastructure as well as the quantities and use patterns can vary significantly depending on the primary purpose of the building. For example, while showers and toilets are particularly important in residences, schools, hotels and office buildings, heat, ventilation and air conditioning (HVAC) systems and landscaping can be major users of water for shopping centers and other large commercial and institutional settings.`

Water Use in Residential Buildings

Owners of residential buildings need adequate supply of water for use in the following areas:

  • Toilets and showers
  • Drinking
  • Wash-basins
  • Laundry
  • Landscaping
  • Heating, ventilation and air conditioning (HVAC)

It is crucial that water supply systems are properly sized. Owners of residential buildings are often concerned about whether or not there will be enough water supply for their needs. “Enough” water means a sufficient quantity with sufficient pressure to meet the following needs:

  • Everyday use – drinking, cooking, and water for plumbing
  • Seasonal use – lawn and garden watering, car washing, and swimming pool
  • Other special uses – animal watering, crop irrigation and water treatment devices that require backwashing.

A day‟s use may be concentrated into a period of one to two hours, often in different areas of the house at the same time (laundry, bathroom and lawn). The water supply system must be  able to meet this type of peak demand. In addition to providing for regular household use, wells sometimes supply water for heating and cooling purposes. Some energy-conscious home owners install groundwater geothermal systems, which extract and concentrate heat energy from water and make it available for heating or cooling purposes. According to the well construction code in Michigan, there is no minimum gallons per minute a well must produce (Garett, 1998).

Residential Water System Sizing

A properly designed residential water supply system should deliver water at the desired quantity, quality and pressure to any outlet on the system during periods of heaviest use. To accomplish this, the peak demand for the home is determined and the well and pump are sized to meet or exceed the demand. If local geological conditions prohibit the development of a water supply with quantity to meet the demand, additional storage facilities are necessary.

Distribution Systems

Water distribution system can be classified into the following:

Piping Networks

Some of the earliest water systems in the United States were constructed using wooden water mains; however, cast iron, steel, and copper were the standard for these systems for much of the 20th century. Recently, advances in plastic pipes, for example high-density polyethylene (HDPE), have brought more of this type of pipes into water utility systems. Plastics have some significant advantages in weight and cost, but there are some issues with pressure ratings, and none of these pipes have been in the ground long enough for engineers to really understand the longevity of these systems. While many of the plastic pipe materials appear to have good long- life characteristics, connections may have less reliability.

When designing water distribution systems for residential buildings, it is important to analyse the criticality of water supply to each building type. While the loss of water supply to a classroom or office building could be merely an inconvenience, the loss of water supply to laboratory or animal care facilities for even a relatively short period of time could endanger critical research (Brook, 2011).







Polypropylene (PP) pipes, Polyvinyl chloride (PVC) pipes, fittings and fixtures

Design Considerations

For the design of a water supply to a residential building, considerations include:

Materials Selection

Materials are selected based on availability, cost and durability. Two most common materials currently used for potable water supply lines are copper and plastic (polypropylene and polyvinyl chloride). The materials for the plumbing piping were selected to offer the following advantages:




Tables 4.1 – 4.2 show the results obtained for cold water supply to the bungalow and the calculated diameters of branched cold water supply pipes discharging to sanitary appliances respectively, while Figure 4.3 shows the results obtained for hot water supply to the building.




From the discussions carried out, the following conclusion can be made:

  1. The design analysis of cold and hot water supply to a 3 bedroom bungalow with 8 occupants has been successfully carried
  2. The adequate flow pressure required is found to be 20 Pa
  3. The standard pipe size for the supply of both cold and hot water has been found to be 19 mm while the average diameter of branched pipes supplying water to the three bedroom bungalow is 13
  4. For the cold water supply, pipes number „1‟ and „2‟ have 34 loading units while pipes 3, 4, 5, 6 and 7 have respectively 3.5, 6.5, 4.0, 6.5 and 13.5 loading units (LU).
  5. The loading units for hot water supply to the building for pipes number „20‟,„21‟, „22‟ and „23‟ are found to respectively 4.5, 4.0, 4.5 and 11.5 LU.


At the end of the work, the following recommendations are made:

  1. Copper pipes should be compared with pipes made of propylene for plumbing in terms of life expectancy, and to know which of them provide better form fitting.
  2. Further work should be targeted on estimating water demands, an estimate of the amount of water expected to be used by the customers


  • Barta, L., (2007). Modelling of Domestic Hot Water Tank Size for Apartment Buildings II. A paper presented at the33rd International Symposium on Water Supply and Drainage for  Buildings, Brno, Czech Republic, pp. 87-98
  • Belobratova, M., (2011). Comparative Analysis of Finnish and Russian Regulating Documents     on Water Supply and Drainage of Residential Buildings. A Bachelor‟s thesis submitted to the Department of Building service Engineering, Mikkeli University of Applied Sciences, Mikkeli
  • Bhatia, A.B.E., (2012). Sizing Plumbing Water System. A PDH online Course M126prepared by PDH Online/PDH Center,5272 Meadow Estates Drive Fairfax, VA 22030-6658, an approved continuing education provider. Retrieved June 12, 2016 on
  • Bratsch-Blundel, R., (2008). Introduction to Water Pipe Sizing: Understanding the Many Methods to Size Water Pipe. Ontario PlumbingInspectors Association Inc., Education and Training. Retrieved July 28, 2016 on [email protected]
  • Brook, J., (2011). Water Supply to a Duplex: A Cross Comparative Analysis. A Thesis submitted to the Faculty of California Polytechnic State University, San Luis Obispo in Partial Fulfillment of the Requirements for the Degree ofMasters‟ of Science in Building Service.
  • Garrett, R.H., (1998). Hot and Cold Water Supply. Blackwell Science Ltd, Second Edition. Graham N., (2012). Design of plumbing systems for multi-storey buildings. Blackwell Publishers, 4th Edition
  • Helena de Oliveira, L., Ilha, M.S.O., and Gonçalves, O.M., (2007). Design flow rate simulation using probabilistic and empiric methods for water sub metering system in Brazilian multifamily Buildings. A paper presented at the33rd International Symposium on Water Supply and Drainage for Buildings, Brno, Czech Republic, pp. 99-109
  • Ho, B.P.L., (2010). Design of Cold and Hot Water Systems. MEBS6000 Utility    Services, Department of Mechanical Engineering, the University of Hong Kong. Retrieved August 22, 2016 on