Centrifugal pumps/fans with variable demand controlled by throttling — the cube law makes part-load savings huge.
From our guide: Variable-speed drives & motors — full context, charts and sources there.
Boilers, kilns, heat exchangers, valves and steam lines lose energy continuously. Inzonex makes patented (UK GB2508992.1) removable modular insulation — snap-fastened covers engineered per temperature tier, not generic off-the-shelf jackets: