The difference in efficiency between the various techniques used to extract heat from synthetic turf surfaces so that it can be used at a later time, and, if necessary, elsewhere, is mainly determined by the choice of pipes and the flow rate of the fluid, says Rob de Heer of Sport Pitch System

De Heer has been working with hoses and piping systems for sports surfaces for decades. Often, these were to be used for heating and draining the surface. More recently, the question of heat extraction has been added. “A lot depends on the material from which the pipe is made, the pipe diameter and the flow rate of the fluid used to extract the heat from the surface,” he says. “This, therefore, requires precise coordination of the pump capacity, layout of the pipe matrix and a good choice of heat transfer system, better known as the heat exchanger.”

In the absence of practical data, he launched a study this summer. “We installed test strips using three different techniques, which we monitored 24 hours a day. The test fields simulate a pipe length of 75 metres, which is the width of a synthetic turf football pitch. We also recorded relevant weather data such as solar radiation, ambient temperature, perceived temperature and the relative humidity.” De Heer intends to use this to map out the algorithm for all energy transfer parameters, so that, based on data from the weather service, an accurate prediction of the efficiency of a particular synthetic turf application that also needs to collect heat, can be made. “The ultimate goal is to provide the market with realistic system control, whereby, based on weather forecasts, it can be decided in advance whether heat should be harvested or whether it is pointless to turn on the pumps at certain times.” It is all about fine-tuning, he believes.

Limited return

Every day, the sun emits almost 11,000 times the energy than the world actually needs. However, it is not the amount of sunlight hitting the synthetic turf that determines the efficiency of the heat extraction of the pitch.