Plumbing Water Heater Recovery Time Calculator
Solve actual tank recovery energy under independently measured input/efficiency and concurrent draw loss, rejecting no-positive-recovery states; not single energy/power conversion or delivery guarantee.
Description
Recovery time divides required heat by net delivered heating power.
Recovery time divides required heat by net delivered heating power. Concurrent draw loss reduces that power.1
The returned values include Net available recovery watts, Modeled tank recovery minutes. The How section below explains the calculation, input rules and interpretation.
When to use Plumbing Water Heater Recovery Time Calculator
Use Plumbing Water Heater Recovery Time Calculator when you need to evaluate the supplied records under the calculation and evidence rules below. No changing temperatures, thermostat cycling or standby model is supplied.
Prepare measured flows, pressures, temperatures or inventories with consistent units. For catalog tools, use independently verified capacities at the stated operating conditions and supply the explicit design demand.
How to use Plumbing Water Heater Recovery Time Calculator and understand its results
- Prepare measured flows, pressures, temperatures or inventories with consistent units. For catalog tools, use independently verified capacities at the stated operating conditions and supply the explicit design demand.
- Enter observedRequiredTankReheatJ, measuredHeaterInputWatts, callerDeliveredEfficiencyFraction, observedConcurrentDrawLossWatts using the field table and calculation rules, then run the tool.
- Read netAvailableRecoveryWatts, modeledTankRecoveryMinutes. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| observedRequiredTankReheatJ | Observed required tank reheat j | number | Required |
| measuredHeaterInputWatts | Measured heater input watts | number | Required |
| callerDeliveredEfficiencyFraction | Caller delivered efficiency fraction | number | Required |
| observedConcurrentDrawLossWatts | Observed concurrent draw loss watts | number | Required |
Enter nonnegative required joules and loss watts, positive input watts and efficiency in (0,1]. Require positive net power even for zero required energy. Return net watts and recovery minutes.
netPower=inputPower×efficiency−drawLoss; minutes=energy/netPower/60 Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| netAvailableRecoveryWatts | Net available recovery watts | number |
| modeledTankRecoveryMinutes | Modeled tank recovery minutes | number |
{
"input": {
"observedRequiredTankReheatJ": 3600000,
"measuredHeaterInputWatts": 2000,
"callerDeliveredEfficiencyFraction": 0.75,
"observedConcurrentDrawLossWatts": 500
},
"output": {
"netAvailableRecoveryWatts": 1000,
"modeledTankRecoveryMinutes": 60
}
}Limitations and assumptions
No changing temperatures, thermostat cycling or standby model is supplied.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Plumbing Water Heater Energy Calculator: Sensible water-heating energy depends on volume, temperature rise and volumetric heat capacity. Input energy includes an explicit efficiency. For a complementary task, use Plumbing Water Heater Sizing Calculator: A storage heater mixes hot water with colder supply water to meet a draw. Recovery during the draw offsets the required usable storage.
References
Similar or alternative tools
- Plumbing Water Heater Energy Calculator
Sensible water-heating energy depends on volume, temperature rise and volumetric heat capacity. Input energy includes an explicit efficiency.
- Plumbing Water Heater Sizing Calculator
A storage heater mixes hot water with colder supply water to meet a draw. Recovery during the draw offsets the required usable storage.