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Commercial · Self-Storage FacilitiesSelf-Storage Climate Control & Heating
Self-storage climate control and heating means holding a building between roughly 13°C and 27°C with relative humidity under about 55%, and of the two numbers, humidity is the one that protects what your tenants store. Mould, rust and warped furniture come from damp air, not warm air, so dehumidification does more work than cooling in an Ontario storage building. We install and service the rooftop units, unit heaters, dehumidifiers and remote alarms that keep a mostly empty building inside that band.
Climate-controlled has no legal definition for storage in Ontario, so the definition is whatever your rental agreement and website promise. The working standard in the industry is a temperature band of about 13°C to 27°C with humidity held below roughly 55%, which keeps a margin under the damper conditions where mould takes hold on fabric, paper and cardboard. Heated-only storage is a lesser promise: the building is kept above freezing in winter and left alone in summer. Know which one you are selling before you buy equipment, because the second needs unit heaters and the first needs a way to remove moisture in every season.
A storage building is an odd load: almost no people, no cooking, few lights and nothing giving off heat. A rooftop unit sized by floor area satisfies the thermostat in a few minutes, shuts off, and never runs long enough to wring moisture out of the air. That short-cycling is behind most complaints in these buildings, with the hallway at 22°C and clammy while the compressor starts and stops all afternoon. The fix is smaller or staged equipment, a control that responds to humidity as well as temperature, and dedicated dehumidifiers for spring and fall days when there is no cooling load at all.
Air goes to the corridors, not the lockers. Ducted supply runs down the hallways, and the lockers share that air through the mesh or open gap above their partition walls, so a locker with a solid lid or goods stacked to the ceiling sits outside the conditioned zone. Outdoor air is the main source of moisture, which makes the rooftop unit's economizer a liability here: free cooling on a mild, damp day off Lake Ontario pulls in exactly the air you are paying to dry. We set minimum outdoor air to suit the low occupancy and lock the economizer out on humidity, not just temperature.
Unstaffed sites need to phone someone when something fails. A tripped rooftop unit or a full dehumidifier pan can go unnoticed for a week in a building nobody walks daily, so we fit temperature and humidity sensors in the corridors that send an alert to the manager's phone. For large heated-only buildings and conversions of older industrial space, the heating side overlaps with our warehouse and industrial HVAC work. The commercial HVAC hub covers the rest, and you can send us the building details for a written quote.
Equipment we install and service
Packaged rooftop units on single-storey buildings and split systems on multi-storey conversions, ducted down the corridors. We favour two smaller units or a staged unit over one large one, because long part-load run times are where moisture gets removed. Units with hot-gas reheat can dry the air without overcooling the hallway.
Ducted or free-standing commercial dehumidifiers that run on a humidistat regardless of temperature. They cover the cool, damp weeks in April, May and October when the cooling never comes on. Each one needs a drain: gravity to a floor drain where possible, a condensate pump where not, and a float switch that stops the unit before the pan overflows into a corridor.
Suspended heaters for heated-only buildings and for the loading bays of climate-controlled ones, holding a low winter setpoint. They are simple, inexpensive to run at storage temperatures and regulated by TSSA as gas appliances. Our commercial unit heater page covers repair and replacement.
Corridor temperature and humidity sensors, a lockable networked thermostat and alarm outputs from each unit, reporting to a phone or the gate-system dashboard. The alert thresholds sit inside your promised band, so you hear about a drift toward 27°C or 55% before a tenant does.
What goes wrong in these buildings
- The hallway is cold and clammy in June and a tenant just found mould on a mattress.
- The rooftop unit kicks on and off every few minutes and the hydro bill does not match an empty building.
- Nobody is on site after five, and the last time a unit quit we found out from a one-star review.
- The dehumidifier pump failed and left a puddle halfway down corridor B.
- We advertise climate-controlled and I could not tell you what humidity the building actually sits at.
How it works
Data loggers go in the corridors and a few empty lockers to record temperature and humidity around the clock, while we note each unit's run time, cycling and outdoor-air setting. The trace shows whether the problem is capacity, cycling, outdoor air or a damp slab. It also gives you a baseline you can show an insurer or a tenant.
Most buildings need changes to staging, fan settings, economizer lockout and dehumidification before they need a bigger unit, and we quote those as separate lines. Cost depends on the volume of the building, how leaky the envelope and doors are, and whether drains and power exist where the dehumidifiers go, so the figure follows the survey. Price bands for common repairs are listed on the pricing page.
Sensors are commissioned with thresholds inside the band you advertise, and alerts are tested to the phones that will receive them. Filters, drains, pumps and belts go on a spring and fall schedule, since a storage building's worst months are the shoulder seasons. Reports are written so an off-site owner can read them.
Common questions
What temperature and humidity should a climate-controlled storage building hold?
A common target is 13°C to 27°C with relative humidity below about 55%. Temperature matters for electronics, candles, vinyl and anything held together with glue; humidity matters for nearly everything else, including wood furniture, mattresses, documents, tools and photographs. If you can only afford to control one tightly, control humidity. Wine, art and archival storage need narrower bands than this and a purpose-built room.
Why is our storage building humid when the air conditioning works?
Because the unit is oversized for a building with no heat sources. It drops the temperature in minutes and shuts off before the coil has condensed much water, and on mild damp days it never starts. Check three things: how long each cooling cycle runs, whether the fan is set to run continuously and re-evaporate water off the coil, and how much outdoor air the unit brings in. A dedicated dehumidifier usually closes the gap.
Can drive-up units with roll-up doors be climate-controlled?
Not in any meaningful way. An uninsulated steel roll-up door facing outdoors leaks more air and heat than a small unit can overcome, and every opening dumps the conditioned air. Operators who want to offer both keep drive-up units as standard storage and put climate-controlled lockers behind an insulated corridor door. If drive-up customers ask for climate control, the honest answer is a different part of the building.
How do we find out when a unit fails at an unstaffed site?
Use sensors that are independent of the equipment. A thermostat on a dead rooftop unit may go dark with it, so we put separate temperature and humidity sensors in the corridors on their own power and connection, alerting two or more phones. Add a fault contact from each unit and a float switch on each dehumidifier. Our commercial thermostats and controls page explains the options.
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