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Commercial · Commercial Thermostats & ControlsCommercial Thermostat & HVAC Controls Installation
Commercial thermostat and HVAC controls installation means fitting a control that matches what a rooftop unit can do: two stages of heating and cooling, a fan that runs for ventilation during business hours, an occupancy signal for the economizer, and a schedule staff cannot override for long. There are three tiers, and the choice follows the number of units and who manages them. One to three units suit a lockable programmable thermostat with remote sensors; several sites suit cloud-managed thermostats; a building with an automation system needs BACnet controllers tied into it.
A residential smart thermostat is built for one furnace and one air conditioner, and a rooftop unit asks for more. Rooftop units from about 7.5 tons up commonly have two stages of cooling and two of heating, written 2H/2C, and a thermostat that can only call one stage leaves half the capacity unused or brings it all on at once. The unit also expects an occupied signal so the economizer opens to its ventilation position during business hours and closes at night. Home thermostats generally have no output for that, and their habit of running the fan only during a heating or cooling call means no outdoor air reaches the space between calls.
Power is the other mismatch. Many home thermostats assume a common wire is present or try to charge themselves through the control circuit, and on a rooftop unit that trickle can chatter a contactor or fail to keep the thermostat alive over a long run of thin cable. The cable to the roof was often pulled with exactly the number of conductors the old thermostat used, so adding stages, a common or an occupancy wire can mean pulling new cable, which is the largest part of the labour on many jobs. The control circuit is 24 V from the unit's own transformer, and every relay, sensor and accessory hung on it has to stay within that transformer's rating.
The first tier, for a shop or office with one to three units, is a commercial programmable thermostat with a keypad lock or locking cover and a remote sensor, so the thermostat can live in a back office while the sensor reads the sales floor. The second is a cloud-managed thermostat: every unit at every site appears under one login, schedules are pushed to all of them, and an alert goes out when a space drifts out of range overnight. The third is a BACnet thermostat or unit controller that reports to a building automation system, where setpoints, schedules and alarms are managed centrally. On those jobs we agree the points list with whoever runs the system.
Set-up is where the savings are, more than the hardware. Occupied and unoccupied schedules matched to real business hours stop the unit conditioning an empty building, and a timed override gives after-hours staff an hour or two before returning to schedule on its own. Setpoint limits keep heating from being pushed above, say, 22°C and cooling below 23°C, and a gap of at least 2°C between the heating and cooling setpoints stops one unit, or two neighbouring units in an open space, from heating and cooling against each other. Holiday schedules and a fan set to run during occupied hours finish the job.
Where the sensor sits matters as much as what it is. After a renovation the thermostat is often found in a private office, over a copier, in afternoon sun or under a supply diffuser, reading a temperature nobody else in the zone feels; a remote or averaging sensor fixes that without opening walls. Low-voltage control wiring is part of our work, while new line-voltage circuits go through a licensed electrical contractor and the ESA. The price follows the number of units, the cable runs to the roof, the control tier and any platform subscription the manufacturer charges, so it comes as a written quote and no flat commercial figure is published.
A thermostat cannot fix a mechanical fault, and we check the unit before blaming the control. A damper that ignores the occupied signal is an economizer repair, and a unit that cannot hold setpoint with both stages running belongs with rooftop unit service. Landlords standardizing controls across a plaza should read strip plaza and commercial landlord HVAC. For the full list of commercial work see commercial HVAC, and a quote starts when you send the shop the number of units and a photo of each existing thermostat.
Equipment we install and service
Seven-day commercial thermostats with multi-stage outputs, an occupancy terminal and keypad lockout. They suit a single tenant with a few units and no wish to manage software, and they keep working when the internet does not.
Wired or wireless sensors that let the control read the space instead of the wall it hangs on. Several sensors averaged across a long sales floor or an open office give one honest temperature for a unit that serves the whole area.
Networked thermostats managed from a web dashboard or a phone, with user permissions by role and alerts by text or email. They suit owners with several locations and property managers who are tired of driving to a site to change a schedule.
Devices that speak BACnet to a building automation system over the building's control network. They expose setpoints, schedules, status and alarms to the front end, and they need their addresses and points agreed with the system's integrator before installation.
What goes wrong in these buildings
- Staff turn it to 26 in the morning and 18 by noon, and the unit never stops.
- The store is heated and cooled all night because nobody trusts the schedule.
- We put in a home smart thermostat and now only half the rooftop unit ever comes on.
- The front unit is cooling while the back unit is heating the same open room.
- I manage several locations and find out about a dead unit when the store manager calls.
- The thermostat is in the manager's office with the door shut, so the sales floor is always wrong.
How it works
We read each unit's wiring diagram and nameplate for stages, heat type, economizer and voltage, count the conductors in the existing cable, and note where the thermostat and sensors should sit. The quote lists the control tier, any new cable and what you will be able to do with it.
Thermostats and sensors are mounted, the common, staging and occupancy wires are landed at the unit, and the control is configured for the equipment type so stages, fan and economizer respond correctly. Each output is tested at the unit, not assumed from the display.
Schedules, setpoint limits, override length, holiday dates and user access are set with the owner or manager present, and written down. Cloud accounts are created in the customer's name, so the building keeps control of its own system whoever services it later.
Common questions
Can I use a Nest or ecobee on a rooftop unit?
On a small single-stage rooftop unit with no economizer, some models will run it if a proper common wire is present. On a two-stage unit with an economizer it is the wrong tool: there is generally no occupancy output for the damper, no lockout suited to a public space, and the fan settings assume a house. Home installations are covered under smart thermostat installation.
Will a new thermostat lower our energy bills?
Only if it changes how long the equipment runs. The savings come from an unoccupied schedule, setpoint limits and a short override, and a building already run that way will see little from new hardware. Where a unit has been holding daytime temperatures all night and all weekend, a correct schedule cuts run hours from the first week. We look at the present settings first and tell you which case you are in.
What does BACnet integration involve?
BACnet is the open protocol most building automation systems use. Integration means installing a thermostat or controller that speaks it, giving it a network address, and mapping its points, such as space temperature, setpoint, occupancy and alarms, into the front end. The automation contractor or integrator owns the front end, so the points list, network type and addressing are settled with them before hardware is bought.
Can staff still adjust the temperature after it is locked?
Yes, inside limits you choose. A typical set-up lets staff move the setpoint a degree or two either way and press an override for after-hours work, while schedules, limits and system mode sit behind a passcode or the manager's login. Full lockout with no adjustment tends to backfire: people bring space heaters, tape over sensors or prop doors, and those cost more than a degree.
Related
Keep the building running.
One licensed team for installs, maintenance contracts and 2 AM calls.