Getting Technical
well enough, provided they use the same supply water from
which the ice was originally made.
Ice rinks on which league level ice hockey is played
regularly do a regular additional ice surface maintenance
operation which takes between 12 and 16 hours weekly.
This is known as “tempering”, a meticulous process by
which trapped air and impurities are released from the
ice sheet by warming it to just below 0°C, shaving and
washing the softened ice with a resurfacing machine (often
repeatedly), then reducing the surface temperature back to
a hockey-friendly -6°C degrees at a methodical rate of not
more than 1°C per hour.
A further benefit from this fusion process is a more
highly bonded ice surface with increased resistance to
further air bubbles and fissures caused by skate pressure
that leave the ice sheet with a cloudy appearance, often
obscuring game lines. However, there is a risk that if
in the course of such maintenance, an operator allows
the rink temperature to creep too close to the melting
point, the ice sheet’s bond with the concrete slab can be
compromised, along with the integrity of rink markings.
“It’s not an easy process,” comments one of the Canadian
ice arena operators. “This thing can go sideways on you in a
heartbeat if you lose your attention span.”
One of the most common
contaminants in water inhibiting
the formation of quality ice is
trapped air bubbles.
Making and maintaining ice sheets has always been the most
labour-intensive part of operating an ice rink, so much so that
in the 1940s an ice rink owner who was also a very practical
mechanical and electrical engineer designed and constructed
the first ice maintenance vehicle. His name was Zamboni,
which is still used on a range of commercial ice surface
maintenance machines today. Other makes are now also
available and can be tailored for specific surface treatments for
different ice qualities and purposes.
As mentioned earlier, an enclosed space such as an ice
rink requires air conditioning for comfort purposes as well as
humidity control to minimise heat transfer at ice surface/air
interfaces. These requirements will be examined in conjunction
with the range of water types needed for reliable operation
within design limits in the forthcoming issue of ‘Getting
Technical’. RACA
www.hvacronline.co.za
RACA Journal I June 2019
53