For a hockey rink at 10 °C, start near 0 °C indoor dew point, about 50% RH, and choose desiccant drying for subzero supply dew points. Size equipment from moisture load and supply-air dryness; curling halls need a lower target, −5 °C at the control sensor.
Quick answer
- Hold a 10 °C hockey rink near 0 °C dew point (about 50% RH); curling halls need −5 °C dew point at 1.5 m above the ice.
- A 24 kg/h design load with a 2 g/kg moisture difference needs about 10,000 m³/h of dry-air treatment at an assumed dry-air density of 1.2 kg/m³.
- Start that airflow selection with four 3,000 m³/h units, then require the corresponding moisture removal at the specified rink inlet condition.
Yakeclimate's RY desiccant rotor dehumidifiers provide modular equipment for this selection; the largest listed model, RY-3000M, has 3,000 m³/h process airflow.
Why does an ice rink develop fog, condensation or frost?
Fog forms when air cools to saturation; roof droplets form on cold structures; frost grows when water vapour deposits on the ice. Each symptom points to a different measurement.
| Symptom | What to measure | First action |
|---|---|---|
| Fog above the ice | Air temperature and dew point across the ice zone, especially after door openings | Reduce incoming moisture and distribute dry air through the affected zone |
| Droplets on trusses or roof lining | Surface temperature alongside the local dew point | Lower local dew point or raise the cold surface temperature through envelope improvements |
| Frost or roughening on the ice | Ice surface temperature, near-ice moisture content and air movement | Adjust moisture control with the ice technician and reduce air jets across the sheet |
For liquid condensation, keep the dew point below the coldest structure. For deposition on frozen surfaces, compare water-vapour pressure with saturation over ice: frost point is the relevant threshold. Below freezing, a water-based dew-point reading and frost point differ. Excessive drying also increases ice sublimation, so control to the playing requirement. ASHRAE psychrometrics.
What temperatures and dew points should you specify?
Use separate ice, rink-air and spectator conditions, with a lower moisture target for curling.
| Area or activity | Starting condition | Selection implication |
|---|---|---|
| Hockey practice arena, game operation | Ice −4 to −5 °C (25 to 23 °F); rink air +8 to +10 °C at 1 m; spectator area +10 °C | A 10 °C / 50% RH starting setpoint gives about 0 °C dew point |
| Small competition hockey arena | Ice −4.5 to −5.5 °C; rink air +8 to +10 °C; spectator area +15 °C | Separate spectator heating from the dry-air distribution over the rink |
| Figure skating, practice arena | Ice −3 to −4 °C; competition air +9 to +11 °C | Set ice temperature for the sport, then set air moisture independently |
| Curling hall | Air +8 °C at 1.5 m; design dew point −5 °C (23 °F); playing ice −4 to −6 °C | Specify the lower moisture duty and gentle distribution above the ice |
Temperature references: IIHF Ice Arena Guide, Table 4.1, p. 59 and World Curling procurement guidance, pp. 3, 6 and 12.
For hockey, we recommend commissioning around 0 °C dew point and checking roof temperatures and ice quality. ASHRAE describes large arenas holding 1.7 °C dew point or lower for the hour before a game; the colder starting point leaves room for moisture peaks. Lower the setting further where cold structures require it. ASHRAE, Ice Rinks.
For curling, start the design at the federation's −5 °C control-point dew point, then tune the ice-zone condition with the ice technician. The control sensor sits above a colder boundary layer; record both conditions during play. World Curling guidance.
How do you convert relative humidity to dew point?
At 10 °C / 50% RH, dew point is 0.05 °C; at 15 °C / 50% RH, it rises to 4.66 °C. The same RH therefore gives substantially different condensation conditions. Dew-point calculation.
Use the Magnus relation, with air temperature T in °C and RH as a percentage:
γ = ln(RH / 100) + 17.625 × T / (243.04 + T)
Td = 243.04 × γ / (17.625 − γ)At 8 °C, a −5 °C dew point corresponds to approximately 39.4% RH. These calculations express dew point relative to liquid water, including supercooled water below freezing. NOAA NCEI, TMY Technical User Guide, equation 1.
Should you choose desiccant, refrigerant or air conditioning?
Choose desiccant drying when the required supply dew point is below freezing; retain a purpose-designed refrigerant system when its low-temperature duty meets the load.
| Method | Best fit | What the selection must include |
|---|---|---|
| Desiccant rotor | Low supply dew points, cold rink air and curling | Reactivation heat, wet exhaust, process-air heat gain and outlet moisture content |
| Refrigerant dehumidifier with low-temperature coils and defrost | Rinks where tested coil performance meets the target | Moisture removal through the defrost cycle, drainage and part-load operation |
| Comfort air conditioning | Spectator comfort and sensible cooling | A separate latent-load check and humidity control when the thermostat is satisfied |
Specialist refrigeration dehumidification remains a valid rink option; ice formation on the coil requires an appropriate defrost design. ASHRAE, Dehumidifiers. For the calculation below, specify desiccant supply air near −10 °C dew point and compare equipment at the stated inlet condition. Use the refrigerant-versus-desiccant selection guide for the broader comparison.
How much moisture must the system remove?
Add outdoor-air moisture, occupants and resurfacing evaporation as separate loads, including the busiest operating period. Warm humid air enters through ventilation, doors and envelope leakage; floodwater and people add moisture inside. IIHF, Dehumidification, p. 72.
For each incoming air stream:
Moisture load, kg/h = dry-air density × airflow × (w_in − w_room)Here, airflow is in m³/h and humidity ratio w is in kg water/kg dry air. Use the actual supply humidity for pretreated ventilation air and outdoor humidity for leakage. Count each stream once.
For a 60 × 30 m hockey sheet, take these explicit calculation inputs: room 10 °C / 50% RH, outdoor air 25 °C / 60% RH, sea-level pressure 101.325 kPa, and rounded dry-air density 1.2 kg/m³. Calculated humidity ratios are approximately 3.8 g/kg indoors and 11.9 g/kg outdoors, using NWS vapour-pressure equations and the ASHRAE humidity-ratio relation.
| Load component | Assumed input for this calculation | Moisture load |
|---|---|---|
| Doors and envelope leakage combined | 1,000 m³/h untreated outdoor air | 1.2 × 1,000 × (11.9 − 3.8) / 1,000 = 9.72 kg/h |
| Occupants | 100 spectators × an assumed 0.05 kg/h per person | 5.00 kg/h |
| Resurfacing evaporation | Assumed 3 kg evaporated during the design hour | 3.00 kg/h |
| Ventilation after separate air treatment | Assumed residual load delivered to the rink | 2.00 kg/h |
| Total | Sum of the four loads | 19.72 kg/h |
| Design allowance | Add an assumed 20% for this calculation | 23.66 kg/h; select at 24 kg/h |
Replace the assumed occupant and evaporation loads with the design occupancy, activity and resurfacing schedule. Count only the evaporated portion of floodwater in the air-moisture load; the remaining water freezes on the sheet. Add players separately according to activity. The 1,000 m³/h leakage assumption is separate from required ventilation.
Maintain the required outdoor-air supply and pollutant controls while reducing uncontrolled leakage. Fuel-driven resurfacers need particular attention to carbon monoxide and nitrogen dioxide. US EPA, Indoor Air Quality and Ice Arenas.
How do you calculate process airflow and unit count?
Divide the design moisture load by the moisture removed from each cubic metre of process air.
Q_process = M_design / [ρ_da × (w_return − w_supply)]With the 24 kg/h load above, return air at about 3.8 g/kg and a required supply condition of 1.8 g/kg (approximately −10 °C water dew point at sea level):
Q_process = 24 / [1.2 × (0.0038 − 0.0018)]
= 10,000 m³/hThis is recirculating dehumidification process airflow. Calculate ventilation, spectator conditioning and distribution requirements separately. For mixed outdoor/return air at the rotor inlet, calculate the mixed humidity ratio and the equipment moisture removal as well.
| Design load and moisture difference | Required process airflow at 1.2 kg/m³ | Initial RY-3000M airflow selection |
|---|---|---|
| 6 kg/h; 2 g/kg difference | 2,500 m³/h | 1 unit |
| 12 kg/h; 2 g/kg difference | 5,000 m³/h | 2 units |
| 24 kg/h; 2 g/kg difference | 10,000 m³/h | 4 units |
| Curling: 6 kg/h; room 2.6 g/kg, supply 1.2 g/kg | About 3,570 m³/h | 2 units |
In the curling row, 2.6 g/kg corresponds to approximately −5 °C dew point, while 1.2 g/kg corresponds to approximately −15 °C, at sea-level pressure. Even a small curling facility can need more airflow per kilogram of moisture because its allowable supply-to-room moisture difference is smaller. See low-dew-point equipment selection.
Where does the Yakeclimate RY range fit?
Use RY equipment as modular drying capacity, with smaller facilities or separate zones offering the most straightforward fit.
| Model | Process airflow | Rated removal at 20 °C / 60% RH | Rated power | Listed supply |
|---|---|---|---|---|
| RY-1500M | 1,550 m³/h | 240 L/day | 15 kW | 380 V / 3-phase / 50 Hz |
| RY-3000M | 3,000 m³/h | 456 L/day | 30 kW | 380 V / 3-phase / 50 Hz |
Four RY-3000M units have a combined rated power of 120 kW (4 × 30 kW); see desiccant dehumidifier power consumption and reactivation energy.
Product specifications: Yakeclimate RY series.
For the 10,000 m³/h calculation, four RY-3000M units provide 12,000 m³/h listed total airflow. Require the selected bank to remove at least 24 kg/h at 10 °C / 50% RH inlet, with the selected supply humidity and installed duct resistance. The 456 L/day catalogue value applies at 20 °C / 60% RH; request a performance selection at the rink condition before fixing the quantity.
Yakeclimate supplies the drying equipment; the project HVAC designer coordinates ventilation, spectator heating and arena air distribution. For a larger arena, compare a modular bank with a specialist central air-handling design, including ducts, space, controls, electrical demand and maintenance access. For US projects, establish the required voltage, frequency and approvals before selecting the electrical configuration.
What installation details affect the result?
Distribute dry air gently, exhaust reactivation moisture outdoors and measure the conditions where the problems occur.
- Separate dry-air delivery from spectator heating. Avoid warm, high-velocity jets striking the ice; arrange supply and return to reach the full zone.
- Keep wet exhaust clear of outdoor-air intakes. Include reactivation airflow in the building pressure balance; see how the rotor air streams work.
- Trend room dew point, supply moisture and cold-surface temperatures. For curling, use the specified control height and add ice-zone readings to check stratification.
- Test peak operation. Log doors, occupancy and resurfacing alongside humidity so that capacity and distribution problems can be distinguished.
- Include process-air heat in the cooling calculation. Compare heater, fan and cooling demand together when assessing desiccant reactivation energy.
FAQ
Frequently asked questions
What dew point should a hockey rink maintain?
About 0 °C is a useful starting setpoint for a hockey rink at 10 °C air temperature, equivalent to roughly 50% RH. Check the coldest roof surfaces and ice condition during busy operation, then adjust the target. Curling needs its own lower moisture specification.
Can ordinary air conditioning control rink humidity?
No, ordinary thermostat-controlled air conditioning alone is unsuitable for a cold rink with a low dew-point requirement. Select dedicated moisture control that operates when sensible cooling demand is low. A purpose-designed refrigeration system with suitable coils, defrost and humidity control is a separate option.
How many 3,000 m³/h units does a rink need?
Four units are the initial airflow selection for a 24 kg/h design load with a 2 g/kg return-to-supply moisture difference and 1.2 kg/m³ dry-air density. Their listed combined airflow is 12,000 m³/h. Confirm removal capacity and duct performance at the specified inlet condition before procurement.
Does lowering room dew point stop every ice-quality problem?
No, ice quality also depends on ice temperature, resurfacing, water quality and air movement. Lower moisture reduces deposition risk, while excessive drying increases sublimation. Check frost point against ice temperature and tune the operating target with the ice technician, particularly where curling pebble consistency matters.
What should you send for a rink sizing check?
Send your ice area, temperature and dew-point targets, occupancy, outdoor design condition, door schedule, ventilation treatment and available power through the rink equipment sizing enquiry.
