The cheapest improvement you can make to a heating and cooling system is not a new unit. It is telling the existing one when to work. In many small commercial buildings, equipment runs on a schedule set years ago, or on no schedule at all, heating and cooling an empty building at night and on weekends. A thermostat that matches the way the space is used can reduce waste without buying anything large.
But thermostats are also a place where good intentions go wrong. A smart device installed with default settings can do very little. A deep overnight setback can leave the building uncomfortable at opening time. Employees who override the schedule turn savings into noise. This guide explains how schedules, setbacks and sensors work in small commercial buildings, where the savings come from and how to set them up so that comfort does not suffer.
Short answer: match schedules to real occupancy, use moderate setbacks, start recovery before opening, limit overrides and place sensors where they reflect the occupied space.
In this guide
- Which control for which building
- Where the savings actually come from
- Setting a schedule that works
- Setback depth: not too deep
- Sensors and placement
- Preventing overrides and fighting thermostats
- Smart features worth having
- Maintenance still matters
- Checking whether it worked
- A simple setup checklist
- The short version
- Thermostat myths
Which control for which building
| Type | What it does | Best for |
|---|---|---|
| Manual | Fixed setpoint adjusted by hand | Very simple spaces with constant use |
| Programmable | Stores time-based schedules for set days | Predictable hours |
| Smart or Wi-Fi | Programmable plus remote access, reports and alerts | Owners who want remote control |
| Commercial controller | Multiple schedules, zones, lockouts and integration | Larger or multi-zone buildings |
| Building automation system | Centralized control of many systems | Larger commercial buildings |
For a small shop or office, a good programmable or smart thermostat with a lockable cover is usually enough. The key is not the label but how it is configured.
Where the savings actually come from
Heating and cooling energy depends on the difference between the indoor setpoint and the outdoor temperature, and on how many hours the equipment runs. Reducing either one reduces use.
- During unoccupied hours, the thermostat allows the temperature to drift: cooler in winter, warmer in summer. The system works less during those periods.
- Aligning start and stop times with actual occupancy avoids conditioning an empty space.
- Avoiding extreme settings and unnecessary overrides reduces overshoot and short cycling.
- Conditioning only the areas in use, when equipment allows it.
How much you save depends on the climate, the building, the equipment and the hours of use. We cannot promise a number, and published percentages should be treated with caution. Record your utility bills before and after changes to see the effect.
Setting a schedule that works
Start with the real hours. Walk through a typical week and note when people arrive, when the building is occupied and when it is empty.
- including early staff and cleaners.
- a comfortable value that people will accept without constant adjustment.
- a more relaxed value that protects the building.
- Equipment needs time to bring the space back to the occupied setpoint. Start the recovery earlier than opening time.
- separately.
- and adjust based on complaints and bills.
Many smart thermostats offer optimal start features, which learn how long the building takes to reach temperature and begin earlier on hotter or colder days. These can help avoid a cold or stuffy start.
Setback depth: not too deep
A deeper setback saves more energy while the building is idle, but it also takes longer to recover. In a building with limited capacity, deep setbacks can mean the space is not ready by opening time, which leads to complaints and manual overrides. Moderate setbacks usually deliver most of the benefit with fewer problems.
Heat pumps deserve special mention. In heating mode, a large setback may trigger auxiliary electric resistance heat during recovery, which uses more energy than the heat pump alone. Some thermostats manage this intelligently; others do not. Ask your contractor how your equipment behaves and what settings they recommend.
For freeze protection, make sure the unoccupied setting prevents temperatures from falling to levels that could damage pipes or sensitive items. Your contractor or building manager can advise on the right values.
Sensors and placement
A thermostat only knows the temperature where it is mounted. If it is in direct sun, close to a vent, next to a kitchen or in a rarely used hallway, it will control for the wrong conditions. Better placement or additional remote sensors improve both comfort and efficiency. Our guide to why offices are too hot or cold discusses how sensor location can cause comfort complaints.
Occupancy sensors can adjust setpoints automatically when a room is empty, which suits conference rooms and shared spaces with irregular use. Humidity sensors can help in climates where moisture is an issue.
Preventing overrides and fighting thermostats
A schedule is only effective if people do not constantly undo it.
- for example allowing a range of a few degrees.
- for requesting changes.
- that revert to the schedule after a set time.
- about how the system works and why settings were chosen.
- where one heats while the other cools in the same space.
A little communication prevents most conflicts.
Smart features worth having
- so you can adjust or check settings without visiting.
- for temperature extremes or equipment problems.
- which show how many hours the equipment ran.
- with building controls, if you have them.
- useful where hours vary.
Be sure the device is compatible with your equipment. Commercial systems often use different wiring and staging than residential ones, and not every consumer thermostat works with every unit. We do not provide wiring instructions; a licensed technician should install and configure controls. Also consider cybersecurity basics, such as strong passwords and updates for connected devices; ask your IT provider if you have one.
Maintenance still matters
Controls cannot fix a dirty coil or a clogged filter. A well-scheduled system that is poorly maintained will still waste energy. Pair control upgrades with regular service, and keep records. Our guide to commercial HVAC maintenance contracts explains what that looks like.
When replacing equipment, ask whether new controls come with the quote and whether staging, variable-speed fans and economizers are included. Our guide to reading HVAC replacement quotes covers these items.
Checking whether it worked
Compare utility bills for the same months before and after your changes, adjusting for weather where possible. Many utilities provide online usage data that makes this easier. Keep a log of complaints and overrides. If the savings are smaller than expected, the cause may be elsewhere, such as an oversized unit, leaky ducts or poor insulation. A contractor or energy auditor can help identify the reasons.
Incentives for controls and efficiency upgrades may be available through utilities and programs. We do not give tax or financial advice; ask the program administrator and your accountant about requirements.
A simple setup checklist
- Record the current settings and the last twelve months of utility bills.
- List real occupancy hours.
- Set occupied and unoccupied temperatures.
- Add a recovery period before opening.
- Lock or limit adjustments.
- Check thermostat placement and sensor readings.
- Review after the first month and again each season.
The short version
Savings come from conditioning the building only when and where it is needed. Match schedules to real hours, choose moderate setbacks, give the system time to recover, protect settings from constant override and keep up the maintenance. A modest investment in controls and attention can deliver more than a new unit ever would, provided the equipment underneath is in good shape.
Thermostat myths
Myth: A deeper setback always saves more.
Reality: It saves more while the building is empty, but recovery takes longer. If the space is not ready at opening, overrides undo the savings.
Myth: A smart thermostat saves energy by itself.
Reality: Only if it is set up well. The default schedule is rarely the right one.
Myth: Controls can make up for a poorly maintained unit.
Reality: A clean filter and coil still do more for performance than any schedule.
