| system | initial cost ($ + hrs) / unit | annualized cost ($ + hrs) / unit | sqft building | acre land | revenue | market cost | benefits |
| ------------------------- | ----------------------------- | -------------------------------- | ------------- | --------- | ------- | ------------- | -------------------------------------------------------------------------------- |
| Cold Water Storage System | $2,540 + 300 hrs | $609 + 54 hrs | 16 sqft | 0 | $0 | $5,000-10,499 | Health benefits from cold plunge therapy, energy efficiency, customized solution |
- This system is designed with reliability as the primary concern, followed by cost-effectiveness. Commercial alternatives would cost $5,000-10,499 upfront, plus ongoing maintenance.
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#### Assumptions
- System provides near-freezing water (35°F) to residential bathtub
- Non-pressurized design with 150 gallon capacity
- Insulated utility room (4' x 4' x 6') with R-60 insulation
- Daily use scenario (one cold plunge per day)
- Operating schedule: 24/7 with automated temperature maintenance
- Internal resource utilization per year:
- Electricity: ~120 kWh
- Water: ~18,250 gallons (assuming 50 gallons per daily use)
#### Market Solutions $3,650-6,650/year
- Commercial cold plunge tubs: $3,000-10,499 initial cost
- High-end commercial products (The Plunge, Sun Home Cold Plunge Pro): $5,000-10,499
- Operating costs: $365/year for maintenance supplies
- Budget options (stock tank with ice): $100-250 initial + $3,650-11,680/year for daily ice
#### Labor 24 Hours/year
| task | hours/year | notes |
| ------------------------ | ---------- | ------------------------------------- |
| Weekly temperature check | 8.7 | 10 minutes per week |
| Monthly leak inspection | 3 | 15 minutes per month |
| Quarterly cleaning | 8 | 2 hours per quarter |
| Annual maintenance | 4.3 | System overhaul and water replacement |
| total labor (hours) | 24 | |
#### Operating Costs $340/year
| component | external cost ($) | notes |
| ------------------- | ----------------- | ------------------------------------- |
| Electricity | $120 | ~$10/month for daily use |
| Water | $80 | Municipal water for filling/refilling |
| Filter replacements | $45 | For UV sterilizer |
| Cleaning supplies | $50 | Food-grade sanitizer |
| Misc. maintenance | $45 | Replacement parts, sealants |
| total annual cost | $340 | |
#### Initial Costs $2,540 + 300 hrs -> $269 + 32 hrs/year
| Component | Initial Cost ($ + hrs) | Lifespan (Years) | Amortized Cost/Year ($ + hrs) | Justification |
| ------------------------- | ---------------------- | ---------------- | ----------------------------- | ----------------------------------------------------- |
| Utility Room Construction | $630 + 80 | 20 | $31.5 + 4 | Rigid foam insulation with higher R-value |
| Water Storage Tank | $385 + 40 | 10 | $38.5 + 4 | Norwesco 150 gal vertical water tank |
| Plumbing Components | $275 + 60 | 10 | $27.5 + 6 | SharkBite PEX system for reliability |
| Cooling System | $1,050 + 80 | 8 | $131.25 + 10 | Active Aqua 1/2 HP water chiller |
| Monitoring & Safety | $200 + 40 | 5 | $40 + 8 | Inkbird temperature controller with redundant sensors |
| total initial cost | $2,540 + 300 | - | $268.75 + 32 | |
#### Specific Components List
##### Utility Room Construction ($630)
- Johns Manville AP Foil-Faced Polyiso Foam Board (R-13, 2" thick): $210 (7 sheets)
- Owens Corning R-23 mineral wool insulation: $180 (6 packages)
- Great Stuff Pro foam sealant: $45 (3 cans)
- OSB sheathing (3/8"): $45 (2 sheets)
- 6-mil poly vapor barrier (Husky): $30
- Foam board adhesive: $20
- Weatherstrip foam tape: $15
- 2x4 pressure-treated lumber: $85
##### Water Storage Tank ($385)
- Norwesco 150 gallon vertical water tank: $345
- Bulkhead fittings (2): $40
##### Plumbing Components ($275)
- SharkBite PEX tubing (1/2", 100ft): $85
- SharkBite fittings kit: $60
- Fluidmaster 400A toilet fill valve (for auto refill): $15
- Watts 9D backflow preventer: $35
- Delta diverter valve: $45
- Armaflex pipe insulation: $35
##### Cooling System ($1,050)
- Active Aqua 1/2 HP water chiller (AACH50): $900
- Ecoplus 396 GPH submersible pump: $35
- Kerick MA052 float valve (redundant level control): $20
- SunTouch WarmWire floor heating mat (under tank for emergency thaw): $95
##### Monitoring & Safety ($200)
- Inkbird ITC-308 temperature controller: $35
- Redundant temperature sensors (3): $30
- Govee WiFi water leak sensors (2): $40
- Honeywell automatic water shutoff valve: $60
- GFCI outlet adapters (2): $25
- UV sterilizer light: $10
#### Reliability Enhancement Features
1. Redundant Temperature Control: Primary Inkbird controller with backup sensors at different tank levels
2. Emergency Heat System: SunTouch floor heating mat under tank to prevent freezing if chiller fails
3. Dual Level Controls: Primary float valve with secondary Kerick valve for overflow prevention
4. Quick-Connect Plumbing: SharkBite fittings allow for rapid repairs without specialized tools
5. UV Sterilization: Prevents biological growth without chemicals
6. Leak Detection with Auto Shutoff: Govee sensors trigger Honeywell shutoff valve if leaks detected~120 kWh
- Water: ~18,250 gallons (assuming 50 gallons per daily use)
#### Market Solutions $3,650-6,650/year
- Commercial cold plunge tubs: $3,000-10,499 initial cost
- High-end commercial products (The Plunge, Sun Home Cold Plunge Pro): $5,000-10,499
- Operating costs: $365/year for maintenance supplies
- Budget options (stock tank with ice): $100-250 initial + $3,650-11,680/year for daily ice
#### Labor 24 Hours/year
| task | hours/year | notes |
| ------------------------ | ---------- | ------------------------------------- |
| Weekly temperature check | 8.7 | 10 minutes per week |
| Monthly leak inspection | 3 | 15 minutes per month |
| Quarterly cleaning | 8 | 2 hours per quarter |
| Annual maintenance | 4.3 | System overhaul and water replacement |
| total labor (hours) | 24 | |
#### Operating Costs $350/year
| component | external cost ($) | notes |
| ------------------- | ----------------- | ------------------------------------- |
| Electricity | $120 | ~$10/month for daily use |
| Water | $80 | Municipal water for filling/refilling |
| Filter replacements | $50 | UV filter or mineral-based sanitizer |
| Cleaning supplies | $50 | Food-grade sanitizer |
| Misc. maintenance | $50 | Replacement parts, sealants |
| total annual cost | $350 | |
#### Initial Costs $2,245-3,060 + 300 hrs -> $299-390 + 30 hrs/year
| Component | Initial Cost ($ + hrs) | Lifespan (Years) | Amortized Cost/Year ($ + hrs) | Justification |
| ------------------------- | ---------------------- | ---------------- | ----------------------------- | ------------------------------------------------ |
| Utility Room Construction | $550-700 + 80 | 20 | $27.5-35 + 4 | Insulated room (R-60) for temperature control |
| Water Storage Tank | $350-500 + 40 | 10 | $35-50 + 4 | 120-150 gal polyethylene food-grade tank |
| Plumbing Components | $230-360 + 60 | 10 | $23-36 + 6 | PEX tubing, valves, fittings, pipe insulation |
| Cooling System | $1,000-1,300 + 80 | 8 | $125-162.5 + 10 | 1/2 HP water chiller, submersible pump |
| Monitoring & Safety | $115-200 + 40 | 5 | $23-40 + 8 | Temperature controllers, sensors, leak detection |
| total initial cost | $2,245-3,060 + 300 | - | $233.5-323.5 + 32 | |
#### System Outputs
| Output Type | Daily Units | Annual Units | Internal Cost ($/unit) | Internal Cost (hrs/unit) | Notes |
| ---------------- | ----------- | ------------ | ---------------------- | ------------------------ | ---------------------- |
| Cold Plunge Bath | 1 | 365 | $0.96 | 0.07 | 35°F water for bathtub |
#### Revenue $0/year
| service category | revenue ($) | notes |
| --------------------- | ----------- | ------------------------------------------- |
| Cold plunge therapies | $0 | For community use only, no external revenue |
| total | $0 | |
_Note: This system is designed for community well-being rather than revenue generation. Commercial alternatives would cost $5,000-10,499 upfront, plus ongoing maintenance._