Beyond Fixed Slab Control

For decades, most ice rinks have relied on a simple control strategy: choose a target slab temperature and keep it there.

While this approach is straightforward and reliable, it assumes that the cooling requirements of a rink remain constant throughout the day. In reality, the demands placed on an ice surface are constantly changing. Over the course of a single day, a facility may host youth practices, figure skating sessions, public skating, tournaments, and competitive hockey games, while also experiencing long periods where the ice sits completely unoccupied. Each of these situations places a different heat load on the ice and benefits from different surface conditions.

Despite these constantly changing operating conditions, many refrigeration systems continue to maintain a single fixed slab temperature. As energy costs continue to rise, this fixed-control approach often results in more refrigeration than is actually needed, increasing electricity costs without improving ice quality.

Every Hour Is Different

The amount of cooling an ice sheet requires depends almost entirely on how it is being used. Consider a typical day:

1. Early morning

   The rink may be empty after resurfacing, with very little heat entering the ice.

2. Midday

   A youth hockey practice introduces players, coaches, and continuous skating activity.

3. Afternoon

   A public skating session can bring dozens of skaters transferring heat into the ice.

4. Evening

   A competitive hockey game, complete with spectators, creates one of the highest heat loads of the day.

5. Overnight

   The facility may sit completely unoccupied for several hours.

These are fundamentally different operating conditions. When special events such as tournaments, PD days, holiday schedules, and camps are added to the mix, the variation in refrigeration demand becomes even greater.

Yet under fixed slab control, the refrigeration system is expected to maintain exactly the same slab temperature through every one of these scenarios.

During quieter periods, the system often cools the slab more aggressively than necessary, consuming electricity without providing any measurable improvement in ice quality. During periods of heavy use, that same fixed setpoint may not provide the ideal conditions for the activity taking place.

Small Temperature Changes Can Deliver Large Savings

The energy implications of even small slab temperature adjustments are significant. As a general rule of thumb, for every 1°C increase in slab temperature setpoint, refrigeration compressors consume approximately 13% less energy. Although the exact savings vary depending on the refrigeration plant and operating conditions, the relationship is remarkably consistent: warmer slab temperatures require less compressor work.

For every 1°C increase in slab temperature setpoint, refrigeration compressors consume approximately 13% less energy.

This creates an important opportunity. Allowing the slab temperature to rise slightly during quieter periods can significantly reduce compressor runtime and electricity consumption while still maintaining excellent ice conditions.

Across an entire season, these seemingly small adjustments add up to substantial energy savings. Rather than operating the refrigeration plant at maximum effort around the clock, facilities can reduce operating costs, lower equipment wear, and extend compressor life without compromising the skating experience.

A Better Approach: Predict Cooling Demand

The next generation of rink refrigeration control moves beyond maintaining a fixed slab temperature. Instead, it continuously adjusts cooling based on both current conditions and anticipated future demand.

This distinction is important because an ice slab has significant thermal inertia. It does not warm up or cool down instantly. Changes made by the refrigeration system affect the ice surface hours later. This means an effective control system must anticipate changing conditions.

For example, if a competitive hockey game is scheduled to begin in an hour, the refrigeration system should begin increasing cooling in advance so the slab reaches its target temperature before players step onto the ice. Waiting until the game has already started is too late. Likewise, if the schedule shows several hours of inactivity ahead, the system can safely reduce cooling and allow the slab temperature to rise, saving energy while remaining fully prepared for the next scheduled activity.

This predictive approach allows facilities to optimize refrigeration throughout the day. Rather than maintaining the coldest possible slab temperature at all times, the objective becomes much more practical: use the least amount of energy possible while ensuring the ice is in the right condition for every upcoming activity.

Achieving this requires combining multiple sources of information, including facility schedules, real-time ice temperature measurements, environmental conditions, and equipment performance. Together, these inputs allow an intelligent control system to anticipate changing heat loads instead of simply reacting after they occur.

Treating every hour of rink usage the same is wasteful. Predictive control continuously balances energy efficiency and ice quality. The result is lower operating costs, reduced equipment wear, and consistently better ice conditions.