Sunday, November 27, 2011

Q&A Answer #2

elvis77 from Section 60 asked:
"Here's an ice related one for you, on Tuesday it wasn't exactly cold out and the building was packed full of screaming kids and the ice looked to still have some wet spots late into each period. How much does the fluctuation in temps the Cincinnati area experiences in the spring and fall effect the ice and do large crowds warm the building as well? Can a random warm day combined with a large crowd create a "perfect storm" of bad/sloppy ice?

It seems that even the local "men's league" rinks can have questionable ice when the temps start fluctuating and it can take a day or so to adjust."

Yes, weather changes can have a huge impact on the ice surface - especially sudden changes. I see the ice as a living, breathing surface. It expands, contracts, moistens, drys, and changes easily. It thrives in a state of equilibrium and it struggles when the equilibrium is disturbed. It reminds me of a Bonzai plant, needing constant grooming and attention.

New modern facilities have a lot of built-in systems to help maintain the balance. They are better insulated, they have dehumidification systems. They have "low emissivity" ceiling membranes to help pull moisture away. They have have an under-ice warming system, below the cold pipes, to keep the ground temperature constant. Older facilities, like US Bank Arena, don't have these added systems.

Even with those amenities, the "bubble" of equilibrium can be disturbed. Sudden ambient temperature increases can cause soft ice until the compressors and air handling systems swing the conditions back into balance. Even a sudden cold snap can dry out the air and cause brittle ice that gets rough quickly and gives up lots of snow.

And then, even if ambient conditions are constant, just introducing a large crowd into the building can upset the balance. Thousands of people bringing in their body heat, and bringing the warm moist air from simply breathing injects heat and humidity into the environment and can change ice conditions. If this happens on a suddenly warm or humid day (even a cold rain can add humidity), then the "perfect storm" scenario definitely applies.

The building engineers have some tricks to help offset the effects. Besides just turning the thermostat up or down, they can manipulate the air handling direction, etc. Sometimes they even fire up the bioler and send a flash of hot air into the building so the humidity jumps onboard and flies out when the air is pushed out through air handlers.

The Zamboni driver has to be very aware of the conditions.  When it's warm and/or humid, water delivery control is critical. During games, I try to use the least amount of water possible to nicely glaze the ice. I turn it down in the corners and even turn it off over the goal creases since I go over that area numerous times. If you drive faster, you have to open the water valve more. If you slow down, water must be reduced. Last Tuesday for Education in Hockey day, Drew was driving because I had a conflict. He has good training and does well, but probably was a little heavy on the water delivery.

The water delivery can be difficult because it is totally operator selected. If snow isn't moving through, the operator can hear it and increase RPMs, slow down, etc. But the water just flows and you have to remember proactively to make adjustments.

When the equilibrium is all out of whack, other weaknesses are exposed. The first is over the goal creases. If the water is not turned down there, it will stay wet because the chiller system doesn't have the capacity to freeze it while dealing with the added stress.  Also, the brine return goes out of the rink in the area of the home player bench at US Bank Arena.  It enters the rink between the visitor bench and the goal line, so it's the coldest right there. Then it snakes its way through pipes around the rink surface to the area of the home bench.

So, at the end of its path, it is at its warmest because it has already exchanged most of its coldness (technically heat is exchanged and coldness is a perception of less heat), so it has the least freezing capacity there. Throw in the temperature change, the exhaled air from thousands of screaming kids, and then too much water, and you're left with wet spots.

At the local rinks where we play in the amateur leagues, they don't have thousands of spectators but they also have virtually no added air handling ability and they don't have an engineer there on staff just to control the air so they are actually more susceptible to weather changes. They also have a hit-or-miss situation with experienced Zamboni drivers.

Don't get me wrong, there are some very good, very experienced ice guys around town. But the rinks also have some newer, less experienced drivers. Also their training is limited nearly exclusively to "on the job training" and even the more experienced drivers who are training the newbees may know how to do things right themselves but they may not be the best communicators or trainers.

As you can see, it's not like just starting up the lawn mower and running a pattern.

Thanks for asking, Elvis. Keep those questions coming! 


Blogger Auntie Sue said...

What about a police car driving around on the ice -- how big a mess does that leave you?

1:08 AM  
Anonymous Anonymous said...

A few other questions: 1. When and why did the Cyclones change the policy of no Zamboni riders? My ticket rep just told me when I requested to get my daughter a ride.

2. What covers the ice during concerts and other events and how does that effect the ice? Does the ice have to be cleaned/ added too, recolored or what?

12:17 PM  
Blogger Guido said...

More great questions, Mr. Anonymous.

The rider decision was made a couple of seasons ago. There are still some places doing it but the Zamboni company discourages it. When Ops Manager Drew went to training put on by Don Zamboni himself, they strongly discouraged it for liability reasons. Not just getting sued, that's just cash; but because no driver would want to be responsible for a child's injury. Those propane tanks are right under the seat. Suppose there is a small leak, and then a fire. Could spell disaster.

The ice gets covered by a material called Pro Deck. It's a fiberboard material with a corrugated bottom so it doesn't stick flat. It goes down in 5x8 sheets, laid out with love by the changeover crew.

When it comes up, it leaves some fibres that mostly get cut up by the Zamboni.

10:41 PM  

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