Why Your TCU Might Be Oversized — And What It Costs You

The industry's dirty secret: catalog matching

When you contact most TCU suppliers with a request — say, "I need a water TCU for my injection mold, process temperature 80°C, around 9 kW heating" — what typically happens is this: a salesperson looks through their product catalog and picks the nearest standard model that covers your specs.

Need 9 kW? They offer you a 12 kW unit. Need 45 l/min flow? They give you the pump that does 60 l/min. Close enough, they figure — and it keeps their stock simple.

The problem is that "close enough" has real costs that add up over years of operation.

What oversizing actually costs you

An oversized TCU doesn't just sit there being too big. It actively wastes money in three ways.

Higher purchase price. A 12 kW unit costs more than a 9 kW unit. A larger pump costs more than a smaller one. You're paying for capacity your process will never use.

Higher energy consumption. A pump that delivers 60 l/min when you only need 45 l/min runs against a throttled circuit. The excess energy turns into heat — heat your cooling system then has to remove. You're literally paying to create a problem and then paying again to solve it.

Larger physical footprint. In a production hall where floor space next to the machine is valuable, an oversized TCU takes space that a correctly sized unit would not.

Why suppliers do it this way

It's not malice — it's logistics. Most large TCU manufacturers produce standard models in fixed configurations. They stock 6 kW, 12 kW, 18 kW, 24 kW units with two or three pump options each. If your need falls between two sizes, you get the bigger one. Their business model depends on volume production of identical units, so customization is either unavailable or comes with 8–12 week lead times and significant surcharges.

This is the trade-off the industry has accepted for decades: fast delivery of an approximate solution, or slow delivery of the right one.

There is a third option

At Boe-Therm, every TCU is configured to order from our production facility in Assens, Denmark. We don't stock standard units and then match your request to whatever is closest. Instead, we configure the heating capacity, pump, cooling, and control system to match your actual process requirements.

Need 9 kW heating with a pump that delivers 50 l/min at 3.8 bar? That's exactly what you get — not a 12 kW unit with an oversized pump.

The key is that this doesn't come with the long lead time you might expect from custom manufacturing. Because our production is modular and in-house, configured units ship in 3–4 weeks — comparable to or faster than many standard-product suppliers.

How to check if your current TCU is oversized

Check your actual process temperature vs. rated capacity. If your TCU is rated for 120°C but your process never exceeds 85°C, you may be using a more expensive pressurized water or oil system when a simpler 90°C or 95°C unit would serve you better.

Compare installed heating kW to actual demand. If your heaters rarely cycle above 60–70% duty, your heating capacity is likely oversized. A correctly sized TCU runs its heaters at 80–95% duty during heat-up and maintains temperature with proportional control.

Look at your pump. If you have a flow control valve that is always partially closed, your pump is delivering more flow than your circuit needs. A smaller pump would deliver the right flow at lower energy cost.

The bottom line

A correctly sized TCU costs less to buy, less to run, and takes up less space. The reason most manufacturers don't offer this is that their production model is built around standard products, not configuration.

If you want to find out what TCU your process actually needs — not the nearest catalog match — try our free online configurator. It calculates your real requirements based on your process parameters and recommends a specific configuration in about two minutes.