Commercial dehumidification services · Greater Montréal, Laval, Longueuil, South Shore and North Shore
Commercial dehumidification in Montréal: we measure, calculate and install the right unit.
Indoor pool, arena, warehouse or offices: every space has its humidity target. We assess your building, quantify the litres of water to remove from the air, then install and maintain the dehumidifier that covers the load.
01 · Understanding HVAC dehumidification
Commercial dehumidification: remove water from the air before it damages the building.
Commercial dehumidification means reducing and controlling the humidity of a building’s air so it stays in a healthy range.
Too much humidity encourages mould and mildew, damages property and makes a space uncomfortable. Well-tuned HVAC dehumidification keeps the air comfortable, healthy and productive: for your customers, your employees and the building itself.
At AirGreen, we treat it as a calculation, not a hunch: how much water enters the air, where it comes from, and which unit removes it at the right rate.
Mould and mildew
Sustained humidity feeds mould on walls, ceilings, cardboard and fabrics. Above about 65%, it finds favourable conditions.
Damaged goods and building
Corroded structures and equipment, warped goods, blistering paint, wet insulation: water in the air always ends up somewhere.
Heavy air and discomfort
Fogged glazing, clammy air, lingering odours: customers notice, employees put up with it, productivity suffers.
02 · Slide the humidity
Raise the slider and watch the room change.
Fog appears as soon as the glass drops below the dew point. Mould waits for sustained humidity above about 65%.
03 · The building in cross-section
Pool, arena, warehouse, offices: every space has its humidity target.
Tap a number to see what happens, the recognized target and the line we install for that case.
Indoor pool: what happens without control
Water evaporates non-stop. Left uncontrolled: fogged glazing, dripping ceilings, corroded structures and a lingering chlorine smell.
Why this target. Below 50%, water evaporates faster and energy costs climb; above 60%, air quality and the building suffer.
Who does what. If the chosen unit also heats the pool water, the water-side connection is done by a licensed partner plumber.
Source: ASHRAE Handbook, HVAC Applications 2019, ch. 6Air 1 to 2 °C warmer than the water, never above 30 °C
Our line for this caseSECARR SDS11.95 to 73.2 lb/h at 82 °F (27.8 °C) and 60% RH · 11 models in our catalogue
Calculate my pool’s evaporationArena or ice rink: what happens without control
Humid air meets cold ice: fog above the rink, water dripping from the ceiling, poorer ice quality.
Why this target. A maximum dew point of 7.2 °C usually eliminates fog. A conventional air conditioner is not suited to an ice rink.
Who does what. A gas-regenerated desiccant dehumidifier needs a licensed gas fitter: we coordinate with a partner.
Source: ASHRAE Handbook, Refrigeration 2018, ch. 44Large arenas: ≤ 1.7 °C during the hour before a game
Our line for this caseSECARR IRD6.5 to 21 lb/h near 60 °F (15.6 °C), per the manufacturer · 5 models in our catalogue
Check my dew pointWarehouse or basement: what happens without control
Warm, humid summer air comes in and meets cold walls and slabs: musty smell, warped cardboard, rusting metal, stained walls.
Why this target. The 30 to 50% target comes from Health Canada and the INSPQ to limit mould. A closed space does not dry out on its own.
Source: Health Canada (2023); INSPQ, appendix 6 (2016)Above about 65%, mould finds favourable conditions
Our line for this caseSECARR SDA5.5 to 26.5 lb/h at 82 °F (27.8 °C) and 60% RH · 7 models in our catalogue
Calculate my moisture loadOffices or retail: what happens without control
A system that cools without drying enough leaves the air clammy: discomfort, odours, condensation on cold ducts.
Why this target. Since 2019, ASHRAE 62.1 limits the indoor dew point to 15 °C in mechanically cooled buildings, even overnight.
Source: ASHRAE 62.1, addendum ae (2019); RSST, s. 119Winter: at least 20% RH during working hours (RSST, s. 119)
Our line for this caseSECARR SDA5.5 to 26.5 lb/h at 82 °F (27.8 °C) and 60% RH · 7 models in our catalogue
Calculate my moisture load04 · Calculate
Calculate your space’s moisture load, hour by hour.
Three calculations we redo at the visit with your real measurements. Move the sliders: the result and the model follow.
evaporation = 0.1 × area × (pwater − pair) × FaWarm water pushes vapour into the air; the bigger the pressure difference, the more it evaporates. The Fa factor accounts for swimmers and waves.water (kg/h) = 1.2 × outdoor air (m³/h) × (Woutdoor − Wtarget)In summer, Montréal air can carry 16.7 g of water per kg of air. Everything above your target that comes in must be removed.05 · The chart
Move the point: the standard, fogging and mould respond.
The engineers’ psychrometric chart, simplified. Each curve is a relative humidity; the higher the point, the more water the air carries.
06 · Our units
Our SECARR commercial dehumidifiers, made in Saint-Jérôme.
Three Thermoplus Air lines, from 5.5 to 73.2 lb/h. Capacities from the manufacturer’s data sheets, verified October 14, 2026.
No number yet? Start from a typical case below, calculated with the same equations we use at the visit (water at 28 °C or 27 °C, air 1 °C warmer, 55% RH; warehouse at 0.3 air changes/h in summer).
SECARR SDA · general use
SECARR SDS · indoor pools
SECARR IRD · ice rinks
| SDAF-012 | SECARR SDA | 5.5 | 2.5 | 60 | 300 | R-410A | Details |
| IRD-020F | SECARR IRD | 6.5 | 2.9 | 71 | 1,200 | R-448A | Details |
| SDAF-016 | SECARR SDA | 6.7 | 3 | 73 | 400 | R-410A | Details |
| IRD-035F | SECARR IRD | 11.5 | 5.2 | 125 | 2,800 | R-448A | Details |
| SDAF-024 | SECARR SDA | 11.6 | 5.3 | 126 | 565 | R-410A | Details |
| SDS-026 | SECARR SDS | 11.95 | 5.4 | 130 | 1,000 | R-410A | Details |
| SDAF-030 | SECARR SDA | 13.1 | 5.9 | 143 | 660 | R-410A | Details |
| IRD-050F | SECARR IRD | 14.5 | 6.6 | 158 | 3,400 | R-448A | Details |
| SDS-036 | SECARR SDS | 16.2 | 7.3 | 176 | 1,350 | R-410A | Details |
| SDAF-038 | SECARR SDA | 16.8 | 7.6 | 183 | 840 | R-410A | Details |
| IRD-075F | SECARR IRD | 17.5 | 7.9 | 191 | 4,000 | R-448A | Details |
| SDAF-048 | SECARR SDA | 20.3 | 9.2 | 221 | 970 | R-410A | Details |
| IRD-100F | SECARR IRD | 21 | 9.5 | 229 | 5,500 | R-448A | Details |
| SDS-051 | SECARR SDS | 23.7 | 10.8 | 258 | 2,000 | R-410A | Details |
| SDAF-060 | SECARR SDA | 26.5 | 12 | 288 | 1,280 | R-410A | Details |
| SDS-060 | SECARR SDS | 30 | 13.6 | 327 | 2,500 | R-410A | Details |
| SDS-072 | SECARR SDS | 33.5 | 15.2 | 365 | 3,000 | R-410A | Details |
| SDS-083 | SECARR SDS | 39.6 | 18 | 431 | 3,500 | R-410A | Details |
| SDS-090 | SECARR SDS | 42.6 | 19.3 | 464 | 3,800 | R-410A | Details |
| SDS-103 | SECARR SDS | 50.3 | 22.8 | 548 | 4,800 | R-410A | Details |
| SDS-120 | SECARR SDS | 58.3 | 26.4 | 635 | 5,500 | R-410A | Details |
| SDS-137 | SECARR SDS | 65.5 | 29.7 | 713 | 5,700 | R-410A | Details |
| SDS-154 | SECARR SDS | 73.2 | 33.2 | 797 | 6,400 | R-410A | Details |
No model in this line reaches that capacity: we combine several units or move to a custom system.
All 34 units are also on the Commercial dehumidifier page and in the Dehumidifiers collection. For a pool, an air exchanger often completes the installation.
07 · The technologies
Four ways to dry the air, each in its place.
Choose your case: the technology we most often choose is highlighted.
Refrigeration
SECARR SDA, SDS, IRDAir passes over a cold coil; vapour condenses and drains away. The air leaves drier, then reheated.
Desiccant
Wheel or absorbent bedAn absorbent material captures the vapour, then is dried (regenerated) with heat.
Outdoor air with heat recovery
Air exchangerHumid air is replaced with outdoor air, recovering its heat on the way.
Air conditioning alone
Heat pump, rooftop unitThe cold coil dries the air, but only while the unit is cooling.
08 · The standards
The humidity targets to meet, in plain words.
Six official benchmarks, then the same targets side by side. They guide our calculation.
In a mechanically cooled building, the indoor dew point stays at 15 °C or less whenever the outdoor dew point is above 15 °C, occupied or not. Overnight, up to 12 h at 65% RH maximum is allowed.
Addendum ae to 62.1-2016, approved August 2019Air 1 to 2 °C warmer than the water in public and institutional pools, never above 30 °C. Below 50%, energy use rises sharply.
HVAC Applications Handbook 2019, ch. 6A maximum dew point of 7.2 °C usually eliminates fog. In large arenas, the target is 1.7 °C or less during the hour before a game.
Refrigeration Handbook 2018, ch. 44The indoor range to aim for to limit mould. Above 50%, or as soon as condensation appears, dehumidify.
Moisture and mould guide, 2023In offices and commercial establishments built or operated after December 19, 1979, during working hours. The regulation sets no maximum.
RSST, s. 119, updated to June 1, 2026The theoretical threshold above which mould finds favourable conditions: 60 to 70% depending on the organization.
Fungal contamination toolkit, appendix 6 (2016)The targets on one relative-humidity scale
Ice rinks and air-conditioned buildings are controlled by dew point rather than %: 7.2 °C and 15 °C (see the chart above).09 · Our services
Our commercial dehumidification services, from assessment to maintenance.
Four services, one accountable team, everywhere in Greater Montréal.
HVAC dehumidification system assessment
We examine your building and existing HVAC system, measure humidity and cold surfaces, and pinpoint the areas that would benefit from better drying.
- On-site measurements, free of charge
- Load calculation: evaporation, outdoor air, occupants
- A clear report, before any quote
Dehumidification system installation
Based on your needs and our assessment, we install a dehumidifier that controls humidity continuously and improves comfort and air quality.
- SECARR units from 5.5 to 73.2 lb/h
- Ducts, refrigerant circuit, electrical: RBQ 15.8, 15.10, 16
- Commissioning and set-point adjustment
Maintenance and repairs
We maintain and repair dehumidification systems so they stay efficient and keep the space comfortable, season after season.
- Filters, coils, drain, controls
- Refrigerant circuit checked by our refrigeration technicians
- On our installations and on existing units
Custom dehumidification solutions
Every commercial space has its own challenges: we design a tailored solution, from a single unit to a system combined with ventilation or heat recovery.
- Pool, arena, warehouse, offices
- Paired with an air exchanger when useful
- Coordination with licensed partners
10 · Our personalized approach
A tailored approach, in six steps.
Every building has its needs. We work with you to balance humidity, improve system efficiency and extend the life of your HVAC equipment.
We come on site, free of charge: dimensions, water or ice temperature, glazing, existing ventilation, signs of moisture.
Evaporation, outdoor air, occupants: we quantify the pounds of water per hour to remove instead of guessing a size.
One unit, one installation, one price. You receive the final quote before any work starts.
Ducts (subclass 15.8), refrigerant circuit (15.10) and electrical (16) by our crews. The rest by licensed partners.
Humidity and temperature set points adjusted, drain checked, first reading of the results.
Filters, coils, drain, controls: we keep the unit efficient and repair it when needed.
11 · Why AirGreen
Why choose AirGreen for your building’s dehumidification.
AirGreen is a Montréal HVAC company serving businesses in Montréal, Laval, Longueuil, the North Shore and the South Shore. Your choice of contractor shapes the comfort, efficiency and healthiness of your commercial space: here is what we bring.
Expertise and experience
Refrigeration technicians who install and maintain the units themselves. RBQ licence 5645-9605-01 in ventilation (15.8), refrigeration (15.10) and electrical (16). Calculations based on ASHRAE guides and manufacturer data sheets.
Customer-focused approach
From the first visit to after-service follow-up: free on-site estimate, a written quote with the final price before any work, one contact who knows your file.
Sustainable solutions
The right unit at the right size, set to the right target: less wasted energy, equipment that lasts, and heat recovery when your building allows it.
Who does what, each trade in its place
- Refrigerant dehumidifiers (SDA, SDS, IRD) and their refrigerant circuit
- Ducts, grilles and ventilation
- Electrical supply and humidity controls
- Commissioning, maintenance, repairs
- Water-side connection when the unit heats the pool water (plumbing)
- Natural gas or propane for a gas-regenerated desiccant
- Roof openings and structural supports
- Sealed plans for a public building or large project: we install to the engineer’s specs
- Operating set points (hours, seasons, events)
- Financial-aid application with Hydro-Québec
Our licence. RBQ 5645-9605-01, subclasses 15.8 Ventilation, 15.10 Refrigeration and 16 Electrical. Anything outside them goes to a licensed contractor, and we coordinate.
Everywhere in Greater Montréal
Commercial dehumidification services in Montréal, Laval, Longueuil, the South Shore and the North Shore.
12 · True or false
Seven common beliefs about humidity. Test yourself.
True or false, each answer is explained and cites its source.
13 · Prepare the visit
Eight things to gather before our visit.
Nothing is mandatory: we measure on site. But with these, the calculation is more accurate and the quote comes faster.
14 · Financial aid
A pool that recovers its heat can get support.
What current programs say, with no promises: only the organizations confirm the aid granted.
Hydro-Québec, Efficient Solutions
Heat recovery from indoor aquatic basins is one of the program’s measures. The dehumidifier itself is not a listed measure.
Under the custom offer, support can reach up to 75% of eligible costs in an existing building, based on electricity savings (minimum 25,000 kWh per year). Conditions change: have Hydro-Québec confirm your project before signing.
Énergir
The studies and implementation program pays $1 per cubic metre of natural gas saved in the first year. Heat recovery qualifies only if it reduces your gas use. Pools and arenas are not named: it is case by case.
Participant guide, revised February 25, 202615 · Further reading
Our articles on commercial dehumidification.
Detailed answers from our blog to dig deeper into your case.
16 · FAQ
Frequently asked questions about commercial dehumidification.
It means reducing and controlling the humidity of a building’s indoor air. Too much humidity encourages mould, damages property and makes the space uncomfortable; well-tuned dehumidification keeps the air comfortable, healthy and productive.
Fog or drips on glazing and cold ducts, a musty smell, stains or mould, rust, warped cardboard, fog above the ice. Health Canada advises dehumidifying as soon as humidity exceeds 50% or condensation appears.
Health Canada recommends 30 to 50% indoors to limit mould. In an air-conditioned building, ASHRAE 62.1 instead sets a maximum indoor dew point of 15 °C. A pool is kept between 50 and 60%; an ice rink is controlled by dew point.
Water evaporates continuously, and faster when the air is dry or colder than the water. That vapour condenses on anything colder than the dew point: glazing, frames, structure. ASHRAE recommends 50 to 60% RH and air 1 to 2 °C warmer than the water.
An air conditioner removes water only while it cools. In spring, fall or a heated pool, it does not run enough to dry the air. For an ice rink, ASHRAE deems a regular air conditioner unsuitable.
It is calculated: water evaporation, incoming outdoor air, occupants, processes. The calculators on this page give an order of magnitude. At the visit, we measure and confirm the model before the written quote.
They are Thermoplus Air’s three SECARR lines. SDA: compact general-purpose units, 5.5 to 26.5 lb/h. SDS: indoor pools, 11.95 to 73.2 lb/h, horizontal or vertical. IRD: ice-rink defoggers, 6.5 to 21 lb/h.
Our SECARR units work by refrigeration: air passes over a cold coil and the water condenses on it. ASHRAE also describes desiccant systems for ice rinks. If gas-regenerated, the gas side goes to a licensed gas fitter.
Yes: filters, coils, drain, controls and refrigerant circuit, on our installations and on existing units.
Hydro-Québec lists heat recovery from indoor aquatic basins in its Efficient Solutions program. The dehumidifier alone is not listed. Have Hydro-Québec confirm your project before signing.
Montréal, Laval, Longueuil, the South Shore and the North Shore. Showroom in Boucherville.
Thermoplus Air, in Saint-Jérôme, Québec. The capacities shown on this page come from its data sheets.
No answer for that word. Call us at 514 316-2973: we’ll answer in person.
AirGreen · Commercial HVAC
A space that’s too humid can be fixed. We measure, calculate and install.
AirGreen serves businesses in Montréal, Laval, Longueuil, the North Shore and the South Shore with complete, tailored commercial HVAC solutions. A partner who keeps your building efficient, comfortable and healthy, from the visit to maintenance.
- ASHRAE Handbook — HVAC Applications 2019, ch. 6 “Indoor Swimming Pools” (humidity, temperatures, evaporation equation, activity factors)
- ASHRAE Handbook — Refrigeration 2018, ch. 44 “Ice Rinks” (dew points 7.2 °C and 1.7 °C)
- ASHRAE 62.1-2016, addendum ae (August 2019); Trane Engineers Newsletter vol. 52-2, May 2023 (indoor dew point ≤ 15 °C)
- ASHRAE Handbook — Fundamentals 2017, ch. 16 (psychrometric constants); NIST SP 811 (1 lb = 7,000 grains)
- NOAA/NCDC Engineering Weather Data, Montréal/Dorval, 1973–1996 (peak humidity 117 grains/lb, 0.4% level)
- Health Canada, moisture and mould guide (2023); INSPQ fungal contamination toolkit, appendix 6 (2016)
- Regulation respecting occupational health and safety, chapter S-2.1, r. 13, ss. 116 to 120 (LégisQuébec, updated to June 1, 2026)
- Thermoplus Air Industries, Saint-Jérôme: SECARR brochure 2021, SDA, SDS and IRD data sheets (REV 1); airgreen.ca catalogue as of October 14, 2026
- Hydro-Québec, Efficient Solutions: participant guides of March 2026 and “Heat recovery” pages; Énergir, Studies and Implementation guide (rev. February 25, 2026)
The capacities and calculations shown are estimates; only a full on-site calculation sets the right unit, and only the responsible organizations confirm financial aid.