When choosing or upgrading a commercial gas meter, the key question isn’t just “How much gas do we use?” but “How much gas might we need at once?”
This is where Peak Flow—also called Gas Load—comes in. Understanding it ensures you have the right meter size, prevents pressure drops, and avoids costly meter replacements later.
What Is Peak Flow (Gas Load)?
- Peak Flow refers to the maximum amount of gas your business could use at one time.
- Gas Load is the formal technical term used by suppliers, surveyors, and engineers. In practice, both mean the same thing.
It’s not about your annual consumption. A business with modest yearly use can still have a high peak demand if multiple appliances run simultaneously. For example, a bakery may only bake at certain hours, but when ovens, boilers, and water heaters all fire together, the load spikes.
Why It Matters for SMEs
- Correct Meter Sizing – Suppliers base meter selection on load, not annual use. An undersized meter will restrict flow.
- Compliance & Safety – Gas regulations require equipment to be installed to match capacity safely.
- Cost Efficiency – Oversizing means higher standing charges. Undersizing means downtime and expensive remedial works.
For SMEs, especially in catering, manufacturing, hospitality, or multi-site retail, getting this right avoids headaches when expanding or changing equipment.
How to Estimate Your Peak Gas Load
The simplest way to estimate is to list every gas appliance in your building, note its input rating (usually in kW), then convert to cubic metres per hour (m³/h).
Conversion formula (approximate):
Gas Load (m³/h) = kW ÷ 10.83
(10.83 is the conversion factor for natural gas in the UK.)
Example Table: Estimating Gas Load
| Appliance | Input Rating (kW) | Converted Load (m³/h) | Notes |
|---|---|---|---|
| Commercial oven | 40 | 3.7 | Check plate/sticker on unit |
| Gas boiler (heating) | 70 | 6.5 | Manufacturer’s datasheet |
| Hot water heater | 30 | 2.8 | Often overlooked in calculations |
| Fryer | 20 | 1.9 | |
| Total Load | 160 kW | 14.9 m³/h |
Peak Load: 14.9 m³/h
This means the business needs a meter capable of handling at least 15 m³/h, such as a U16 meter.
Key Considerations
- Diversity Factor – Not all appliances run flat out at once. Engineers sometimes apply diversity (e.g. 80% of total). But for meter sizing, suppliers usually require the maximum possible load.
- Future Proofing – If you’re planning expansion (extra oven, second boiler), include it now. Upgrading later is disruptive.
- Meter Types – In the UK, the most common meters for SMEs are:
- U6 – up to ~6 m³/h
- U16 – up to ~16 m³/h
- U25 / U40 – for higher loads
Common Mistakes SMEs Make
- Only quoting annual consumption – Suppliers cannot size meters accurately from this alone.
- Forgetting secondary equipment – Hot water heaters, air heaters, or standby boilers often push load over the threshold.
- Ignoring peak periods – Seasonal businesses (restaurants at dinner service, gyms at winter peaks) may underestimate true load.
Getting Professional Help
While you can estimate using the method above, a Gas Safe engineer or your supplier’s technical team should confirm the figure. Incorrect load estimates can delay installations and may even result in supply refusal.
At Niccolo, we help SMEs navigate the process—from initial calculations to supplier approvals and installation.
Next Steps
If you’re planning a new connection, changing meters, or simply unsure whether your current meter is right for your business:
- Gather appliance ratings (kW or BTU).
- Use the conversion formula to calculate total load.
- Compare against meter capacities.
And if you want a quick, no-obligation check, our team can calculate your load and recommend the correct meter type.