Indoor rinks are big energy consumers and many arenas are taking steps to cut down on those expenses and the carbon footprint they produce. In the next couple of articles, I’ll be talking about radical, energy-saving, planet-saving alternatives to how arenas are making ice. But first, I’m going to teach you why hot water has been used to make and maintain ice for decades, maybe even a century or more, and demonstrate why so many rinks have a hot water addiction. And we’ll do an experiment so you know exactly what I mean and why hot water helps. It’s all about the science!
You might be surprised to learn that ice for indoor rinks is made and maintained using EXTREMELY HOT water. That’s to get rid of the tiny gas bubbles that are a part of water. Now everyone knows that water is designated as H2O – with a water molecule made up of two hydrogen atoms bonded with one oxygen atom. But the water used to make ice for a rink is usually the same water as a municipality’s drinking water, and that contains other things too, like fluoride for your teeth, calcium, other dissolved minerals…and micro bubbles.
By heating that water up to twice as much as what anyone could use for a shower after a skate, these tiny bubbles begin to disappear. The water is heated to 70ºC (158ºF), or more to get these bubbles to disappear. When you consider the typical water coming out of the tap is at 7ºC (44ºF), that’s a lot of energy required to go from cold to hot.
And it’s not just about the temperature change: it’s also about the amount of water that’s needed.
To build the ice from scratch, a typical NHL sheet requires anywhere between 45,400 – 56,000 litres (12,000 -15,000 gallons) of water. Then, there’s the resurfacing that’s needed to maintain the ice. The typical ice resurfacer holds around 600 litres (175 gallons) of water and the ice may be resurfaced after 20 minutes of play, after each two periods of play, or after each game or practice. Some extremely busy indoor rinks are resurfaced 15 times a day or even more (think about any given Saturday at the rink) so imagine how much water — and energy — is required to heat the water just to fill up the Zamboni, Engo, Olympia – or what ever ice resurfacer your rink uses.
Seeing is Believing
To demonstrate what I’m talking about, I’ve put together an experiment so you can see what these micro bubbles are! All you need is a pan and some water from the tap and a stove to heat it up on. If you’re a child, ask an adult for help. The water doesn’t need to boil: you can turn the stove off after you observe the micro bubbles in the pan.
- Pouring the water from the tap into a pan
- Putting the pan on the stove and heating it up
- Observing what happens.
After the pan has been on the stove heating up for a couple of minutes, look into it. You’ll see there are teeny tiny bubbles clinging to the sides and the bottom of the pan. As the water gets warmer, those bubbles begin loosening up, moving away from the walls and the bottom, rising to the surface and disappearing into the air when they hit it.
Tiny bubbles may be great in champagne, but when they’re in the water used to create or maintain ice, they create a fragile, bumpy surface and as the ice breaks, it creates a snow buildup that becomes heavy to skate through.
I can’t track down when hot water first started being used to create ice surfaces, but the first arena built with refrigeration under the surface was in London for the 1908 Olympics. Four figure skating events were added to what was mostly a summer Olympics, and as they were held at the end of October, 1908 – months after the other events – they contributed to the longest Olympics in history – spanning six months and 4 days.
As time went on, improvements were made on the refrigeration side including one by an electrical engineer named Frank Zamboni who modified how the refrigeration pipes were laid out underneath the ice and got his first patent (of 15) for his design. Using this concept, he, a brother and a cousin build the Iceland Skating Rink in what is now Paramount, CA. Originally an outdoor rink which was quickly converted to an indoor rink, the surface was renowned for it’s quality, flat instead of a wavy one of most rinks due to the placement of the refrigeration pipes underneath.
Of course, Frank Zamboni’s interest in ice and skating continued and he went on to solve another ice problem, inventing the first mechanical ice resurfacer and alternative to the labour-intensive scraping, towelling and shovelling that was required to keep an ice surface smooth and skatable until then. Today, the Iceland Paramount is still in business, still boasting quality ice and just a block away is where the Zamboni Company has been manufacturing the ice resurfacer that bears his name, since 1949.