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PLANT-04 · Central plant

Boiler and chiller running at the same time

The building is calling for both heating and cooling at the central plant simultaneously.

Capacity-basedBAS trendsMedium effort

What does PLANT-04 mean?

The building is calling for both heating and cooling at the central plant simultaneously.

Why does it matter?

Some buildings genuinely need this (interior cores vs perimeter), but most don't — and when they do, the changeover band and economizer schedule are usually mistuned. Each overlapping hour burns gas and chilled water together.

What should you do?

Audit the heating-cooling changeover schedule. Check whether economizer ride-time has been removed. Look for zones with leaking heating valves driving cooling demand elsewhere.

How Energy Agent prices a finding

Written by Pelorus Engineering · Brent Waluzak, P.E. (FL), President, Pelorus EngineeringLast updated
Estimate it

What is heating and cooling at the same time costing?

Estimate the energy spent fighting yourself.

1 ton of cooling is 12 kBtu/h.
Enter a repair or controls-change cost to see the simple payback.
Avoidable cost per year—Energy —Simple payback Enter a cost to fix to see the payback.

    Cooling that only exists to cancel heating (and vice versa) is priced on both sides: chilled water at your kW/ton and rate, heat at your boiler efficiency and gas price, for the hours the overlap lasts. Energy Agent finds the overlap in valve and coil trends.

    Screening estimate. Energy Agent measures the real fault hours and load from your trends and prices them at your tariff.

    Request a demoSee how Energy Agent prices a finding

    Screening-level estimates; confirm with measurement and verification before capital commitment.

    More central plant faults

    All 18 central plant rules →

    See these rules run on your building.

    Send twelve months of interval data and a BAS trend export. Energy Agent returns a ranked list of what is wasting money, what each item is worth per year at your tariff, and what to do about it.

    Request a demoBenchmark your building