Cold Storage

Log both inlets and outlets at a repeatable load, calculate the approach, and compare like with like over weeks. A rising approach at steady flow means the surface is fouling, while one that moves with load is just the operating point. Set a trigger value so cleaning lands in a quiet period instead of a heat wave.

It is one of the better uses for it. Freezer floors need gentle heat underneath to stop frost heave, and the temperature required is low enough that condenser heat carries it easily through a glycol loop. A plate exchanger moves that heat in to the subfloor circuit, so tell us the floor area and the loop temperatures.

The water side, almost always. Condenser and tower water bring scale and biological growth, and a glycol loop fouls when its inhibitor runs out. The refrigerant side stays sealed. That pattern is the practical case for semi-welded units on ammonia plants, since the side that needs cleaning is the side that opens.

A cold store runs well below design load for long stretches, at night, over weekends and in cool weather, and a pack sized only for the summer peak then runs with low velocity in its channels. Low velocity costs heat transfer and lets deposits settle. Give us the minimum load as well as the peak, and the selection is checked at both ends so the pack still performs when the store is quiet.

Often, where stock value is high and the plant has no idle hours. Two frames, each able to carry most of the load, let one be opened while the store stays cold. The extra capital is easier to judge against the cost of one spoiled room than against the price of the exchanger alone.

Schedule it for the season with the lowest load, have the full gasket set on site before the frame is opened, and arrange standby capacity or a second unit to carry the duty meanwhile. A regasket done to plan takes a short outage. One done after a leak forces itself onto the calendar.