Replacing Heating System Pumps with Smaller Pumps to Reduce Life Cycle CostÂ
The heating system in an office building required renovation. The options considered were replacing the 3 existing pumps with ones that were the same power and eventually replacing the thermostatic valves, as well as redesigning the system to have four sub-systems with optimized dimensions using equal friction loss per pump. The latter option allowed for smaller pumps to be used which cut down on the life-cycle cost.
Category: Blogs, Case Studies October 3, 2025
Intended Audience: Building Services
Objective: Renovate the heating system in an office building with the most cost effective option.
Description of System: The heating system in an office building had to be renovated, because of the aged pumps and shortcomings in operational functions. As a result of poor dimensioning of the system, 156 radiators needed three pumps, with a total power of 3240 W. The radiator very near to the pumps had a high differential pressure, which was not really necessary, causing problems due to throttled flow. Also, the thermostatic valves were working in the wrong control range, leading to poor control of room temperature.Â
Description of Intervention: The renovations considered included the following:
A. Replacing pumps with the same power as those installed and eventually replacing the thermostatic valves.
B. Redesigning the system to have four sub-systems with optimized dimensions leading to all systems having equal friction loss allowing smaller pumps to be used.
See Table 1 below:
Table 1: Summary of ResultsÂ
Summary of Results: This analysis indicates that even with a relatively expensive redesign of the system, it is still possible to gain considerable savings in energy and LCC as shown in Table 1.
Conclusion: Numerous similar cases exist in buildings, but many poorly designed systems in industrial applications would benefit from optimization to reduce losses. Optimizing the system with equal system pressure losses and installing smaller pumps also solved the noise problems in the radiators, which were positioned near the pumps.Â
Written by:
Members of the Committee, 1st EditionÂ
Published In: Pump Life Cycle Cost: A Guide to LCC Analysis for Pumping Systems, 2nd EditionÂ
Year of Publication: 2021Â
Pump Life Cycle Costs: A Guide to LCC Analysis for Pumping Systems – 2nd Edition – Pumps.org
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