Transformers for Office Buildings
The substation is usually in a basement or rooftop plant room, which makes dry type construction, low noise and compact dimensions the deciding factors.
Office building load is dominated by HVAC, lifts, lighting and an increasingly heavy IT and server load. Daily and seasonal variation is large, but peak diversity is also high — not every floor is at full load at once.
The substation is usually in a basement or rooftop plant room, which makes dry type construction, low noise and compact dimensions the deciding factors.
What Matters for This Application
- Peak HVAC load in summer and heating load in winter
- Lift and escalator regenerative and starting loads
- Growing IT and data room load
- Tenant churn changing the load profile
- Noise transmission into offices above or below the plant room
- Limited plant room space and restricted access routes
Recommended Transformer Solution
- Dry type cast resin transformer for indoor plant rooms
- Low-noise core design with anti-vibration mounting
- Low loss design to reduce continuous building energy cost
- Forced air cooling for short-term peak coverage
- Splitting the load across two transformers for resilience
- Temperature monitoring integrated with the BMS
Sizing Guidance
Office demand is usually calculated per square metre for lighting and small power, plus actual plant ratings for chillers, lifts and IT, with a diversity factor applied across floors and tenancies.
Installation Notes
- Place the transformer away from quiet areas or use an acoustic enclosure
- Use flexible busbar or cable connections to avoid transmitting vibration
- Provide adequate plant room ventilation for the continuous heat output
- Allow for future capacity: space, cable routes and switchgear ratings
Testing and Commissioning
Before energisation the unit is checked on site: insulation resistance, voltage ratio and vector group, earthing and terminations, and functional checks of protection and monitoring devices. See the testing page for the full programme.