Let’s look at how making a Life Cycle Cost analysis can save money.

In this imaginary scenario, the hotel's facility management team embarked on a project to retrofit the air conditioning system to achieve energy savings. The chilled water system was changed from a constant flow to a variable flow, allowing the system to adapt to the cooling load. This made way for substantial savings using variable speed pumps.

Let’s look at 3 different pump solutions with 3 different overall prices.

The first solution we will look at is a variable flow system with a constant speed pump.

The second solution is a variable flow system with a variable speed pump. The pump is operated in proportional differential pressure mode.

The third solution is identical to the second solution and the pump is again operated in proportional differential pressure mode. However, this time with the “quadratic” feature activated. The pump simulates the pressure requirement in the system at any flow rate without the installation of remote pressure sensors. The result is an optimised pump curve that allows for additional power savings.

As you can see, the total cost of ownership of the systems varies greatly over a 20-year period. Notice the initial prices compared to the total costs. As expected, the most expensive system is the one with the constant speed pump. Pumps without speed control should always be avoided.

The most economical system is the third system.

The variable flow system is serviced by a variable speed pump. The pump is operated in differential proportional pressure mode with the quadratic curve feature activated. So what's the payback time for the higher initial cost of the most economical system? Well, in most cases, it's less than a year. On average, the payback time of systems with variable speed pumps versus uncontrolled pumps may be counted in months, depending on the size of the pump. From there on, you save money and protect the environment for many years.