ZenithArea Manager

Free tool · Sustainability

Energy & Water

Type the meters as you read them: electricity, gas, water, district heat or heating oil, on any day and as often as you read them. The tool works out the use between readings and spreads it over the days, converts gas from m³ into kWh as the bill does, and shows the use, the cost and the CO₂ of each meter for any period, per occupied room night in a hotel or per order or pallet in a warehouse. Each meter is compared with its own baseline, and a week that drifts above it becomes a signal and an action.

1 · Meters

One line per meter you read: the main electricity meter, the gas meter, the water meter, a sub-meter for the kitchen or the cold store. The price is the energy or water price per unit without the fixed charges (Grundpreis); the figures of the example are only examples, take yours from your contract or last bill.

Electricity, gas and district heat are priced per kWh, as on the bill; heating oil per litre; water per m³ including wastewater.

Gas meters count m³; the bill converts them into kWh: kWh = m³ × calorific value (Brennwert) × Zustandszahl, the method of DVGW worksheet G 685. Both figures are on your gas bill. 11.0 kWh/m³ and 0.95 are defaults only: take yours from your bill.

Heating oil: 10 kWh per litre is a default (heating oil EL, net calorific value). Take the figure your supplier gives.

2 · Add a reading

Tick it when this is the first reading of a new meter (a swap, a reset). With the old meter's last reading the use up to the swap still counts; without it the days since the reading before stay a gap and are shown as one. A reading lower than the one before without this tick is treated as an error and also left as a gap.

A reading closes the days before it: the use between two readings is spread evenly over the days between them, so weeks and months can be built from readings taken on any day. Days not between two readings of a meter have no figure; they are never filled in.

Paste from Excel or CSV

One row per reading, columns in this order: date, meter, reading, meter replaced (x), old meter's last reading, note. The meter is named as in the list above. Tabs, semicolons or commas all work, and a header row is skipped.

3 · Per occupied room or per unit optional

The figure the use is divided by, day by day: occupied room nights in a hotel, orders or pallets in a warehouse. Enter one day at a time or paste a list of days. A figure entered here wins over the one from Hotel KPIs.

4 · Period, meter, baseline and CO₂
Show results for

Empty boxes use the defaults shown. The baseline is the first complete weeks with readings (or the period you set), per occupied room or unit when there are figures, else per day. A week more than the threshold above it is a signal.

CO₂ factors

CO₂ factors per kWh (water per m³). The defaults are rounded and count CO₂ only, without other gases or the upstream chain: check the current UBA value or your supplier's label, and type your own.

Default 0.38 kg CO₂/kWh: Umweltbundesamt (UBA), German electricity mix 2023, estimate, CO₂ only. Check the current UBA value or your supplier's label.

Default 0.201 kg CO₂/kWh: BAFA information sheet on CO₂ factors, natural gas, per kWh on the net calorific value (Hi). Check the current value.

No default: the CO₂ of supply and wastewater treatment depends on the utility. Leave it empty or type the figure your utility gives.

No default: district heat is supplier-specific. Type the CO₂ factor your supplier publishes for your network.

Default 0.266 kg CO₂/kWh: BAFA information sheet on CO₂ factors, heating oil, net calorific value. Check the current value.

Gas bills are in kWh on the gross calorific value (Brennwert, Hs); the BAFA factor for natural gas is per kWh on the net calorific value (Hi). The tool divides by Hs/Hi = 1.11, the ratio for natural gas in DIN V 18599.

5 · Readings

No readings yet. Add the first one above, paste from Excel, or .

The guide · Edition 7 · Page 49

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