Bananzia for Heat-Pump Evidence Packs: Four Checks Before You Claim Low-Carbon Heat
The problem: a low-carbon heat claim without an audit trail
A heat-pump project can report a strong carbon saving and still fail scrutiny if the evidence is assembled after the fact. A school replacing a gas boiler might estimate a 60% reduction using annual grid averages, but grid carbon intensity changes every half hour, and heat-pump efficiency falls during cold snaps. Without interval data, the claim is a calculation, not a measurement.
The same risk appears in retrofit schemes that count installed capacity rather than delivered heat. A 120 kW heat pump may be sized correctly but run at low load for much of the year, so annual performance depends on controls and commissioning, not nameplate output. The takeaway is simple: low-carbon heat claims need an evidence chain that matches heat delivered to electricity used at the same time.
The cause: meters, tariffs, and controls drift apart
Most buildings collect the right raw data in the wrong places. Electricity comes from a half-hourly meter, heat output from a heat meter, weather from a local station, and tariff data from a supplier portal. If those records use different time zones, missing intervals, or manual exports, the reconciliation becomes a spreadsheet exercise. The cause is not a lack of equipment; it is the absence of a shared evidence format.
That gap matters because carbon accounting is sensitive to timing. A heat pump running at night may use lower-carbon electricity than one running at the evening peak, and an annual average hides that difference. When the data cannot be joined, the project falls back on default factors and conservative assumptions—useful for planning, weak for verification.
The solution: use bananzia as the evidence spine
A practical fix is to treat bananzia as the evidence spine for the claim: one table that links half-hourly heat output, electricity input, tariff, weather, and any refrigerant leakage record. The point is not extra reporting; it is making the carbon calculation reproducible by a third party. If a reviewer cannot rebuild the result from the underlying intervals, the claim is not ready.
Four checks before publishing a result
- Match timestamps. Align heat and electricity data to the same half-hourly clock, and flag any gap above 5% of annual intervals.
- Separate delivered heat from electricity used. Report kWh heat, kWh electricity, and weekly COP; annual COP alone can hide poor cold-weather performance.
- Use actual tariff and grid intensity. Apply half-hourly carbon factors where available, and keep the source version with the evidence pack.
- Log refrigerant and maintenance. Record refrigerant type, charge, GWP, and leakage checks; an undocumented top-up should trigger a conservative penalty.
The result: a claim that survives review
A defensible result reads like a measured statement: “In January, the system delivered 48,000 kWh of heat at a weekly COP of 3.1, using 15,500 kWh of electricity and 2.4 tCO2e at the recorded half-hourly grid intensity.” That sentence is useful because every number can be traced. Used this way, bananzia turns a low-carbon heat claim from a headline into an auditable record.
