Hatchery water held at 26–32 °C year round
How a shrimp hatchery with 600 m² of larval rearing tanks can keep its seawater at 30–31 °C with heat pumps, and what it saves against a diesel-fired hot water boiler.
▶Video: Pools, spas and hatcheries
V12 · 2–2.5 minTitanium-exchanger heat pumps for pool and seawater heating
Video coming soon01Problem statement
- Larvae need stable temperature. Shrimp larvae survive and moult best at 30–32 °C. Night drops of even 2 K slow growth and raise mortality.
- Daily water exchange. Fresh seawater at 26 °C or less must be heated every day as tanks are partly exchanged.
- Diesel and generator dependence. Diesel boilers and heaters need fuel stock, frequent servicing and attention during power cuts.
- Losses between fuel and process. Burning diesel in a boiler or heater and distributing the heat loses a quarter or more of the fuel's energy before it reaches the process.
- Compliance, safety and handling. Fired equipment brings boiler inspections, fuel storage and unloading, flue emissions and an attendant on every shift.
02Use case
The reference hatchery produces vannamei post-larvae on the east coast. It runs 600 m² of covered larval rearing tanks plus maturation and algae sections, exchanging about 100 m³ of filtered seawater a day.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Seawater exchange heating | 26 → 31 °C | 100,000 L/day seawater, ρ 1.025, cp 3.99 | 568 |
| Tank surface and wall losses | 31 °C held | 600 m² covered tank area × 40 W/m² × 24 h | 576 |
| Total useful heat | 1,144 | ||
Averaged over 20 running hours, the heat pumps need about 57 kW.
03P&ID
Tags: HP heat pump, TK tank, SG steam generator, P pump, PHE plate heat exchanger, TCV temperature control valve, TIC temperature indicating controller (panel), TT temperature transmitter, MT moisture transmitter, PT pressure transmitter, LT level transmitter, FS flow switch, NC normally closed. Process fluids are heated through their own exchanger, coil or jacket.
04Solution
System description
- 1 × SE-SP-65U (65 kW) (SE-SP pool heat pump) delivering 38 °C, covering the day's 1,144 kWh in about 17.6 running hours.
- The diesel-fired hot water boiler stays connected behind a normally closed valve as standby.
- Filtered seawater is heated through a titanium PHE in a recirculating loop between a heated reservoir and the larval tanks.
- Incoming exchange water is warmed in the reservoir before it reaches the tanks, so larvae never see cold water.
- The heat pumps run up to 20 hours a day with the reservoir as the heat store.
Selected equipment
| Model | SE-SP-65U × 1 |
|---|---|
| Heating capacity | 65 kW each, 65 kW total |
| COP | 6.7 at A25 °C / W30 °C (data sheet T1) |
| Power input | about 9.7 kW total at rated conditions |
| Rating | titanium-in-PVC exchanger, R410A |
| Supply temperature | 38 °C |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TIC-201 holds the seawater loop at 31 °C by modulating the heat pump output and the PHE bypass. A high-limit switch at 33 °C stops heating to protect larvae. If the loop falls below 29 °C the PLC raises an alarm and the standby boiler can be started.
05Energy saving and ROI
Change any input to match a customer's site. Defaults are typical Indian prices for October 2026. The installed cost is a placeholder; replace it with the actual quotation.
| Existing | Heat pump | |
|---|---|---|
| Daily consumption | – | – |
| Annual energy cost | – | – |
| Cost per million post-larvae | – | – |
| CO₂ per year | – | – |
06Benefits
Better survival
Steady temperature through the night improves larval survival and growth.
No combustion near tanks
No diesel fumes or fuel spills near sensitive larval and algae rooms.
Quiet, automatic running
Heat pumps hold temperature without an attendant feeding or tuning a boiler.
Lower energy cost
Each kWh of electricity delivers about 6.7 kWh of heat at the required temperature, against well under one kWh of useful heat per kWh of fuel burnt.
No flame on site
No burner, flue or fuel tank for this duty, and no fuel deliveries to schedule.
Solar-ready
Running hours can be placed in daylight so rooftop solar supplies much of the electricity, which also cuts CO₂ further.
07Engineering pointers
Site data to collect
- Tank area, depth and covering
- Daily seawater exchange volume and intake temperature by season
- Target temperature for each section
- Current boiler or heater fuel use
- Distance from the shoreline
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
- Winter minimum ambient at site
Design notes
- Seawater corrosion. Use titanium PHEs and plastic pipework on the seawater side. Keep heat pump water away from seawater with an exchanger.
- Biosecurity. Locate the heat exchanger after filtration and UV, and make it easy to disinfect between cycles.
- Salt air. Specify coated condenser fins and stainless fasteners for units near the coast.
- Electrical. About 10 kW of heat pump input at rated conditions, plus pumps and fans. Check spare sanctioned load before ordering.
Service and warranty
Sunniva has supplied 5,000+ heat pumps since 2012, with nine service technicians across India, including remote sites such as Leh. All components carry a one-year warranty.
Talk to us
Hatchery water held at 26–32 °C year round
How a shrimp hatchery with 600 m² of larval rearing tanks can keep its seawater at 30–31 °C with heat pumps, and what it saves against a diesel-fired hot water boiler.
▶Video: Pools, spas and hatcheries
V12 · 2–2.5 minTitanium-exchanger heat pumps for pool and seawater heating
Video coming soon01Problem statement
- Larvae need stable temperature. Shrimp larvae survive and moult best at 30–32 °C. Night drops of even 2 K slow growth and raise mortality.
- Daily water exchange. Fresh seawater at 26 °C or less must be heated every day as tanks are partly exchanged.
- Diesel and generator dependence. Diesel boilers and heaters need fuel stock, frequent servicing and attention during power cuts.
- Losses between fuel and process. Burning diesel in a boiler or heater and distributing the heat loses a quarter or more of the fuel's energy before it reaches the process.
- Compliance, safety and handling. Fired equipment brings boiler inspections, fuel storage and unloading, flue emissions and an attendant on every shift.
02Use case
The reference hatchery produces vannamei post-larvae on the east coast. It runs 600 m² of covered larval rearing tanks plus maturation and algae sections, exchanging about 100 m³ of filtered seawater a day.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Seawater exchange heating | 26 → 31 °C | 100,000 L/day seawater, ρ 1.025, cp 3.99 | 568 |
| Tank surface and wall losses | 31 °C held | 600 m² covered tank area × 40 W/m² × 24 h | 576 |
| Total useful heat | 1,144 | ||
Averaged over 20 running hours, the heat pumps need about 57 kW.
03P&ID
Tags: HP heat pump, TK tank, SG steam generator, P pump, PHE plate heat exchanger, TCV temperature control valve, TIC temperature indicating controller (panel), TT temperature transmitter, MT moisture transmitter, PT pressure transmitter, LT level transmitter, FS flow switch, NC normally closed. Process fluids are heated through their own exchanger, coil or jacket.
04Solution
System description
- 1 × SE-SP-65U (65 kW) (SE-SP pool heat pump) delivering 38 °C, covering the day's 1,144 kWh in about 17.6 running hours.
- The diesel-fired hot water boiler stays connected behind a normally closed valve as standby.
- Filtered seawater is heated through a titanium PHE in a recirculating loop between a heated reservoir and the larval tanks.
- Incoming exchange water is warmed in the reservoir before it reaches the tanks, so larvae never see cold water.
- The heat pumps run up to 20 hours a day with the reservoir as the heat store.
Selected equipment
| Model | SE-SP-65U × 1 |
|---|---|
| Heating capacity | 65 kW each, 65 kW total |
| COP | 6.7 at A25 °C / W30 °C (data sheet T1) |
| Power input | about 9.7 kW total at rated conditions |
| Rating | titanium-in-PVC exchanger, R410A |
| Supply temperature | 38 °C |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TIC-201 holds the seawater loop at 31 °C by modulating the heat pump output and the PHE bypass. A high-limit switch at 33 °C stops heating to protect larvae. If the loop falls below 29 °C the PLC raises an alarm and the standby boiler can be started.
05Energy saving and ROI
Change any input to match a customer's site. Defaults are typical Indian prices for October 2026. The installed cost is a placeholder; replace it with the actual quotation.
| Existing | Heat pump | |
|---|---|---|
| Daily consumption | – | – |
| Annual energy cost | – | – |
| Cost per million post-larvae | – | – |
| CO₂ per year | – | – |
06Benefits
Better survival
Steady temperature through the night improves larval survival and growth.
No combustion near tanks
No diesel fumes or fuel spills near sensitive larval and algae rooms.
Quiet, automatic running
Heat pumps hold temperature without an attendant feeding or tuning a boiler.
Lower energy cost
Each kWh of electricity delivers about 6.7 kWh of heat at the required temperature, against well under one kWh of useful heat per kWh of fuel burnt.
No flame on site
No burner, flue or fuel tank for this duty, and no fuel deliveries to schedule.
Solar-ready
Running hours can be placed in daylight so rooftop solar supplies much of the electricity, which also cuts CO₂ further.
07Engineering pointers
Site data to collect
- Tank area, depth and covering
- Daily seawater exchange volume and intake temperature by season
- Target temperature for each section
- Current boiler or heater fuel use
- Distance from the shoreline
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
- Winter minimum ambient at site
Design notes
- Seawater corrosion. Use titanium PHEs and plastic pipework on the seawater side. Keep heat pump water away from seawater with an exchanger.
- Biosecurity. Locate the heat exchanger after filtration and UV, and make it easy to disinfect between cycles.
- Salt air. Specify coated condenser fins and stainless fasteners for units near the coast.
- Electrical. About 10 kW of heat pump input at rated conditions, plus pumps and fans. Check spare sanctioned load before ordering.
Service and warranty
Sunniva has supplied 5,000+ heat pumps since 2012, with nine service technicians across India, including remote sites such as Leh. All components carry a one-year warranty.