Types of Water Booster Pumps
Single-stage booster pumps are generally used in private residences or other buildings that are located some distance from the municipal water supply. They will also be installed where water pressure at the building is inadequate. They are useful for irrigation systems when the well pump doesn’t have sufficient pressure for the distance the water needs to travel and the water flow need.
Multi-stage system configurations are often used to boost water supply in hilly areas, for both agricultural, commercial, and residential uses. They’re also essential in tall buildings.
Sizing Considerations for Booster Pump Systems in Buildings
Every building or structure will require different sizes of booster pump systems depending on the footprint of the building and the height of the building. As water moves away from the initial entry into the structure, the water pressure goes down and the further it goes the pressure is even less.
When you are in the design phase, this is the best time to ascertain the size of the booster pump system. Be sure to include engineers and any other experts in the conversation that you trust. Having their input in the design phase will mitigate problems with the structure’s water pressure later. The following factors will help you to decide what size you will need.
Flow Rate
Calculate the flow rate or gallons per minute (gpm) - this is based on the “Fixture Unit” method created by the American Society of Plumbing Engineers (ASPE).
The Fixture Unit approach assigns a value to each fixture or a specific group of fixtures normally encountered in a building. Once you determined the total value of the fixtures in the building, the ASPE table assigns the necessary gallons per minute based on the likelihood that multiple fixtures will be used at the same time
Varying Flow Rate
Varying flow rates generally occur throughout the day in buildings depending on building use. This occurs because there are high use times and low use times throughout the day. Most notably in an apartment building or hotel, the flow rate will be less during nighttime hours because people will be sleeping.
Conversely, the morning hours and evening hours would most likely have peak demand. The morning in a residential apartment or multi-family building would result in a peak flow usage as many people get ready for work at the same time. Even when the flow rates vary, there will still need to be constant pressure at each fixture.
Total Dynamic Head
This is calculated by combining the static head (vertical distance or lift) and the friction head (resistance to flow within various components)
As discussed above every floor in a high-rise building translates into the loss of pressure loss the water supply (static head). Friction losses and vertical losses are also considered for water to reach higher floors. Every booster pump system selected is sized to overcome static head and friction losses at a specified gallon per minute or flow rate.
Number of Pumps
Decide on the number of pumps your system will utilize. The numbers of pumps your system needs will depend on the gallons per minute or gpm. Selecting more than one pump for your system allows the pumps to alternate usage. This extends the life of the pumps and maintains the integrity of the system. Your mechanical engineer will be able to help you with this determination.
Final Things to Consider
Enlist the help of professionals and industry experts when designing your building to ensure the proper specifications and building codes are met. Domestic water boosting pumping systems are an integral part of many water delivery systems and should be explored fully before any final decisions are made.
