Ice Rinks: How to melt your energy costs
By EnPowered - December 08, 2020
Ice rinks are some of the biggest polluters and energy users in municipal portfolios. EnPowered simplifies energy management.
It’s a cliché - Canada and hockey, a frozen nation populated by ice skaters. Canada has the most registered hockey players in the world, and the most hockey rinks, with 3,300 indoor rinks as of 2018/2019 according to the International Ice Hockey Federation. Hockey suffuses Canadian culture, but few people realize the toll that our nation’s pastime takes on municipal energy bills and the environment.
Indoor ice rinks account for 40 percent of emissions from municipal corporate buildings and constitute significant chunks of local government energy bills. Canada’s approximately 2,500 arenas with artificial ice each use an average of one million equivalent kilowatt-hours per year. Alongside these energy costs, municipalities spend an average of $53,000 per year on reconstruction, rehabilitation, or infrastructure replacement each year.
Older arenas are particularly bad at saving energy and money, so given existing repair and upgrading costs, municipalities would do well to tackle energy-saving projects at the same time. Savings vary significantly based on the condition of the arena, and the local heating fuel and electricity prices. For example, savings for an arena (estimates based on an arena with one NHL regulation-size rink) in Ontario range from 5 to 65 percent of a rink's energy bill.
More specifically, for rinks in the poorest condition, implementing the kinds of upgrades we will be discussing below, saved on average 730 tons of CO2e and almost $300,000 in operating costs per year. With 30 percent of Canadian rinks in ‘poor’ or ‘very poor’ condition, there are many opportunities for municipalities across the country to slash costs and green their operations.
What improvements can I do in-house?
Let’s look at some of the energy and money-saving actions that in-house arena staff and general contractors can undertake. For starters, one simple move is to paint the arena floor white, in order to decrease heat absorption. Keeping ice temperature as high as possible will also save HVAC costs, as will keeping ice thin: increasing ice thickness by one to two inches increases refrigerant load by 10 percent. Ensuring ice is shaved and free of impurities is also important, as is storing shaved ice outside the arena in order to reduce the cooling of non-rink surfaces.
"Indoor ice rinks account for 40 percent of municipal corporate building emissions."
Allowing ice temperature to rise and air temperature to drop overnight will help decrease energy consumption by allowing the colder air to take up some of the slack from the refrigeration system. Installing energy-efficient lighting improves both energy use as well as reduces the amount of radiant heat from the lights reaching the ice. Using ceiling tiles with low heat emissions can also reduce the amount of heat radiated down unto the ice, which means less refrigeration is needed to maintain ice integrity.
Equipment replacement and more complex options
Alongside the measures mentioned above, there is a wide range of (relatively) more expensive and time-consuming options available to rink owners looking to cut energy bills. A big issue for many older rinks is the lack of heat recovery - ensuring efficient heat recovery is the single most impactful decision that rinks owners can make. Arena’s built before 1995 do not have refrigeration systems that incorporate heat recovery; these systems reject up to three times the amount of energy needed by the entire building for heating.
One option is to employ heat recovery from refrigeration to pre-heat water for showers and for resurfacing vehicles. For example, Halifax’s BMO Arena, a four-rink, LEED Gold facility installed a waste heat recapture system for space and water heating. This move saved the facility $175,000 in annual energy costs, as well as over 500 tCO2e.
Many of these older refrigeration systems also use refrigerants like HFC and HCFC, which pose serious risks to the planet’s ozone layer. By way of comparison, the R-22 HCFC has a global warming potential (GWP) of 1,810, compared to CO2 which has a GWP of 1. If your refrigeration system is already due for an upgrade, why not kill two birds with one stone and install heat recovery and alternative refrigerants such as R-717 Ammonia or R-744 CO2.
Installing capacity sensors linked with an automated building climate control system can allow you to monitor and adjust heating, lighting, and ventilation based on arena capacity. For example, a full arena generates significant heating from body heat, so heating systems can be turned down to save money. Changes to your arena’s brine pumping system can also reap energy savings, such as shifting from a two-pass to a four-pass pump set up in order to reduce pumping power needs. Similarly, installing a variable drive in your pump system can allow you to modify pumping speed to be more responsive based on how much refrigeration is currently needed.
Tailor your energy strategy to your situation
Ice rink owners can employ some or all of the aforementioned energy-saving methods, depending on their budget, and unique situation. Savings will depend on how extensive any changes are, together with the age of the arena in question, as well as local electricity, natural gas, and heating oil prices. If your arena is in a high-carbon municipality (high fossil fuel use for electricity and heating), reducing refrigeration load should be a priority. In low-carbon areas, energy savings are still possible, but a greater focus on refrigerant replacement and reducing natural gas / oil use for space and water heating is recommended.
Alongside informing yourself about local fuel prices, you may have access to provincial and utility energy efficiency incentives, as well as financing options through government or energy services companies. Consider the size of your arena, the number of rinks, the local climate, and how many months out of the year the rinks are in use (savings examples detailed in this article are based on one NHL size rink operating eight months a year).
"Don’t think that only large, multi-rink arenas, can benefit from these kinds of retrofits, or that these changes always need six-figure sums to pay for them."
An example rink in very poor condition was mentioned at the beginning of this article, which noted that operators saw an almost $300,000 reduction in energy expenses. In order to accomplish this, the following changes were made: low-emission ceiling tiles added; waste heat used for subfloor heating, hot water, space heating, and resurfacing; high efficiency light bulbs installed; brine system upgraded from 2-pass to 4-pass configuration.
The capital costs for these upgrades came to $360,000, with a 20-25 year useful life. After these changes, arena owners saw a 43 percent reduction in energy costs. Of this 43 percent, using waste heat for space heating accounted for 57 percent of total savings. Using recovered waste heat to heat water accounted for 16 percent, and changing the brine pumping system accounted for 11 percent.
Don’t think that only large, multi-rink arenas, can benefit from these kinds of retrofits, or that these changes always need six-figure sums to pay for them. An arena in Uxbridge, Ontario installed energy-efficient lighting, high efficiency furnaces and water tanks, an ice control system, and roof insulation for $78,000. This led to annual savings of $67,000 - a remarkable ROI of less than two years. This shows that in the right instances, even a few key changes can lead to impressive savings.