Night-Time Savings: How Safe HVAC Setbacks Pay Off
- Ben Gray
- Aug 25
- 3 min read
Walk into your lab on Monday and everything feels just right: clean benches, stable temperatures, and full ventilation. Now imagine the building working just as smartly while you were away, keeping things safe, but not working harder than it needs to.
That’s the idea behind HVAC setbacks: thoughtful, safety-led adjustments overnight that cut energy use and costs without disrupting your work.
Labs use more energy than offices
Per square metre, labs typically consume 3–5× more energy than standard offices. Much of this comes from HVAC (Heating, Ventilation and Air Conditioning), which often accounts for the largest share. In many buildings, ventilation runs at daytime levels long after everyone’s gone home. Because HVAC is so dominant, even small, safe reductions overnight can add up to meaningful savings.
Ventilation is a safety control
Airflow is a core safety measure in lab spaces, protecting people, samples and experiments. Some spaces like containment labs, biological safety rooms, or rooms with ongoing processes must stay at full airflow.
That’s why any conversation about setbacks should involve and get clear approval from your entire safety team, including:
Lab lead
Environmental Health & Safety (EH&S)
Site operations / facilities team
What is a HVAC setback?
A setback isn’t “switching off”. It’s a smart schedule that gently eases systems when spaces are unoccupied and brings them back before you arrive. An HVAC setback typically includes:
Switching to unoccupied mode in the Building Management System (BMS) to reduce airflow to a safe minimum.
Adjusting temperature set-points to reduce heating/cooling energy use.
Allowing automatic recovery so conditions are back to normal before staff return.
If done well, day-to-day lab operations will feel exactly the same, but with considerable amounts of energy and money saved.
Use your BMS — your HVAC control partner
It is vital to have the right contacts who understand and control your buildings BMS, which is the practical lever for safe, scalable setbacks. The BMS has the ability to:
Program occupied/unoccupied schedules.
Monitor temperature, pressure, and airflow in real-time.
Trigger alarms if anything drifts out of bounds.
Log data to demonstrate both safety and savings.
Six steps to pilot a safe setback
👥 Get the team together: lab lead, EH&S, and site ops (plus a lab user).
🗺 Map your space: choose a low-risk area (e.g. write-up or storage room).
📏 Define safety minimums: document airflow, temperature, and pressure limits.
🖥 Program the BMS: schedule overnight/weekend setback with automatic recovery.
📊 Monitor closely: run for 2–4 weeks, track energy use and environmental data.
🚀 Review and expand: scale up if conditions stay safe and savings are clear.
Small pilots build confidence and create the evidence you need to grow. For some labs, it may be easiest to run a pilot during a longer holiday period, such as Easter or Christmas.
Why site operations will support this
As HVAC is such a big energy user, even modest overnight cut-backs deliver noticeable energy and carbon savings. Those savings can then be redirected into priorities such as equipment upgrades, maintenance or other sustainability actions. Safety and savings can work hand-in-hand.
Action of the Week:
Reach out to your site operations team. Ask whether unoccupied BMS modes already exist, and if you can run a one-room pilot. Start small, measure clearly, and scale when the data supports it.
Want one more easy, related energy win? Head over to The Power of a Closed Sash — a simple fume hood habit that supports the same principle: reduce airflow when it’s safe to do so.
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