⚙️ System Configuration Decree
Answer these queries, brave soul, and we shall divine the thermal velocity of thy water vessel...
🔥 Core System Physics (The Most Sacred Specifications)
The electrical power rating on your heat pump's nameplate. This is the maximum power it can consume, not the heat output. Typical residential units: 6-12 kW.
Surface area of the heat exchanger coil inside your tank. CRITICAL: For optimal performance, you need 0.2 m²/kW of heat pump power. For a 9kW heat pump, the recommended minimum is 1.8 m². Undersized coils significantly reduce system performance. Check your tank specifications.
Water circulation rate between heat pump and tank. Set by your installer using balancing valves. Too low = poor performance. Optimal: 20-30 L/min for residential systems. Check your system specifications.
Electric resistance heater power inside your tank. Standard residential tanks: 3kW. Used when heat pump can't maintain temperature (winter peaks, legionella cycles). Higher power = faster recovery but higher electricity use.
Thermal resistance of tank insulation. Good tanks: R≥2.0. Poor insulation (R<1.5) wastes energy through heat loss. Check tank label or specifications. Higher R = better insulation = lower standby losses.
Temperature around your tank. Basement/utility room: 15-20°C. Heated basement: 20°C. Unheated garage: 5-10°C. Affects heat loss rate - colder environment = more energy wasted.
🏠 Household Demand Prophecies
Total household occupants. Directly affects hot water demand - more people = more showers, baths, and dishwashing. Used to scale energy needs and validate tank sizing.
Per-person shower duration. Quick showers: 3-5 min. Standard: 6-8 min. Long showers: 10+ min. Major factor in hot water demand calculation.
Number of people showering in the morning rush period. Creates peak demand that must be met from stored hot water. Critical for tank sizing.
Evening shower count. Usually lower than morning. Combined with dishwashing for evening peak demand calculation.
Total baths per week (all household members). Baths use ~80L hot water vs ~25L for showers. Distributed across the week for daily demand calculation.
Number of baths taken on the peak day (for worst-case scenario simulation). This is used to show the largest possible temperature drop and recovery time in the graph. For cost calculations, weekly average is used.
Your showerhead's water flow rate. Low-flow eco heads: 6-8 L/min. Standard heads: 9-12 L/min. High-flow heads: 12+ L/min. Check showerhead specifications or measure with a bucket.
How you wash dishes. Eco dishwasher: 5L/day. Manual two-basin method: 8L/day. Manual running tap (wasteful): 15L/day. No hot water: 0L/day. Affects evening hot water demand.
Eco Dishwasher: This option has minimal impact on hot water demand. Calculations show its negligible effect on system sizing.
🌡️ Climatic Conditions & Operational Decrees
Typical winter outdoor temperature in your area. Air-source heat pumps lose efficiency in cold weather. Nordic countries: -10 to -5°C. Temperate: 0 to 5°C. Critical for COP calculation.
Typical summer outdoor temperature. Heat pumps perform best in warm weather. Used for seasonal COP calculations and annual energy estimates.
Coefficient of Performance in winter conditions. Check manufacturer's data sheet for COP at your winter temperature. Good systems: 2.5-3.0. Poor systems: <2.0. Higher COP = more efficient.
COP in summer conditions. Always higher than winter COP. Good systems: 4.0-5.0. Check manufacturer specifications at your summer temperature and tank setpoint.
Hours per day your heat pump does space heating in winter. During this time, it cannot heat the tank (DHW priority systems). Creates 'blackout' periods for tank heating. Well-insulated homes: 6-10 hours. Poor insulation: 12+ hours.
Temperature of water entering your home from the mains. Winter: 5-8°C in cold climates, 8-12°C in moderate climates. Summer: typically 2-4°C warmer. Affects energy needed to heat water.
Target storage temperature. 55°C is optimal: hot enough to prevent Legionella growth during normal operation, cool enough for good heat pump efficiency. Lower temps risk bacteria, higher temps waste energy.
Temperature for weekly sanitization cycle to kill Legionella bacteria. 65°C minimum for 1 hour per health regulations. Higher temps kill faster but use more energy. Always done with electric backup heater.
💰 Financial Reckonings
Your residential electricity rate including all taxes and fees. Check your electricity bill for the total rate (not just generation cost). Used to calculate annual operating costs for comparison.
Yearly maintenance expenses: filter replacement, refrigerant checks, cleaning. DIY maintenance: €25-50. Professional service: €100-200. Includes heat pump and tank maintenance.
🔬 Vessels of Comparison
First tank option to compare. Standard residential sizes: 200-500L. Smaller tanks = lower cost but higher backup heater usage. Larger tanks = higher cost but more storage capacity.
Second tank option to compare. Choose significantly different size from Tank 1 for meaningful comparison (e.g., 300L vs 500L). The calculator will determine which offers better value.
⏰ Temporal Configuration Scrolls
When morning hot water demand begins (24-hour format). Typical: 6-7 AM. Defines start of peak demand period when most people shower before work/school.
End of morning demand peak. Typical: 8-9 AM. Tank temperature drops during this period and needs recovery time afterward.
When heat pump starts reheating the tank after morning demand. Usually right after morning rush ends. Tank recovery happens during this period.
Start of evening hot water demand (dishwashing, showers). Typical: 7-8 PM. Combined with any remaining daytime heating, this can stress smaller tanks.
End of evening demand period. After this, tank has overnight recovery time (unless space heating takes priority).