Plumbing
Hot water recirculation cost
Combine measured pump kWh and user-entered loop heat losses.
Your inputs
Complete the fields for your selected method. Zero means intentionally zero, not unknown. Currency selection labels amounts; it does not convert exchange rates.
How this calculation works
pump energy cost+thermal loss/input efficiency*fuel unit cost.
Pump input is integrated metered kWh; do not apply duty cycle. Heat loss and conversion ratio are supplied; ratio may represent heat-pump COP. No pipe sizing, temperature or sanitation prescription.
What information do I need?
Use records for the same job, equipment or accounting period. Only the fields for your selected entry method are required. An unknown amount is not zero.
Input definitions and where to find them
- Metered annual pump electricity (kWh/year): Integrated annual metered kWh; never apply duty again.
- Electricity price per kWh (selected currency): Matching energy/volumetric tariff or bill component for electricity price per kwh, excluding fixed charges or other charges not modeled.
- Entered annual loop heat loss (kWh thermal/year): Isolated measured/qualified supplied thermal loop loss; not inferred from unisolated bills.
- Delivered heat / purchased input (ratio): Supplied delivered-heat/input ratio replacing that loss.
- Fuel price per kWh input (selected currency): Price per purchased-input kWh using a supplied fuel conversion if required.
Use the Where to find this value controls beside the inputs for available work-it-out helpers. Estimates remain your assumptions; a helper does not verify the source figures.
Worked example
Example amounts use US dollars (USD).
Example answer: Annual pump electricity cost is $75.00 for the illustrative inputs below.
Example inputs
- Metered annual pump electricity: 500.00 kWh/year
- Electricity price per kWh: $0.15
- Entered annual loop heat loss: 3,000.00 kWh thermal/year
- Delivered heat / purchased input: 0.90 ratio
- Fuel price per kWh input: $0.08
- Annual pump electricity cost
- $75.00
- Annual heat loss input-energy cost
- $266.67
- Total annual recirculation energy cost
- $341.67
These illustrative values are not recommended rates or industry averages. Replace every example input with your own figures.
Use the result well
Combine measured pump kWh and user-entered loop heat losses. Some modes require specialist measurements or a qualified equipment/energy estimate. If you do not have those inputs, use a directly measured alternative where offered; do not guess from unrelated bills or equipment ratings.
Keep inputs on the same scope and time basis. Calculations retain precision internally; displayed values generally round to two decimal places, with extra precision for very small values and whole-unit rounding where required. Economic comparisons describe your supplied assumptions and do not guarantee future results.
This tool provides business arithmetic. It does not approve engineering designs, establish legal or tax treatment, select equipment or certify safe operating conditions.