Curd incubation rooms heated by cold-room heat
How a dairy making 15 tonnes of cup curd a day can heat its incubation rooms and yogurt base with heat taken from its cold-room condensers, instead of electric heaters.
▶Video: Waste-heat recovery heat pumps
V10 · 2–2.5 minLifting warm water from condensers, effluent and process cooling to useful heat
Video coming soon01Problem statement
- Incubation is heated with electricity. Rooms are often kept at 43 °C with electric fan heaters, which run for many hours a day.
- Uneven room temperature. Cups near heaters set faster than cups at the back. This gives variation in acidity and texture across a batch.
- Heat and cold side by side. The blast chiller next door removes the same heat again and rejects it to a cooling tower.
- Electric heating is expensive heat. Resistance heaters turn one kWh of electricity into one kWh of heat, at the full commercial tariff. A heat pump moves two to four kWh of heat for the same unit.
- Large connected load. Heater banks take a big share of the sanctioned load and push up maximum-demand charges.
02Use case
The reference plant fills 15 tonnes of set curd and yogurt a day into cups and pouches. Filled cups are incubated at 42–43 °C for 4–6 hours in two rooms, then blast-chilled and stored at 4 °C. Part of the yogurt base comes from milk held in cold storage.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Incubation rooms | 42–43 °C | 2 rooms × 8 kW fabric, air-change and product losses × 12 h | 192 |
| Cup and crate re-warming after filling | 38 → 43 °C | 15,000 kg product/day | 84 |
| Yogurt base tempering | 10 → 43 °C | 5,000 L/day from cold storage | 186 |
| Storage and pipework standing losses | – | about 5% | 23 |
| Total useful heat | 484 | ||
Averaged over 20 running hours, the heat pumps need about 24 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-WW-55V (55 kW) (SE-WW water-source heat pump) delivering 55 °C, covering the day's 484 kWh in about 8.8 running hours.
- A 2,000 L insulated storage tank decouples the heat pumps from the process peaks.
- Heat source: cold-room and blast-chiller condenser water at about 32 °C. Taking heat out of the condenser water lowers head pressure on the cold-room compressors.
- The electric room heaters and immersion heaters stays connected behind a normally closed valve as standby.
- A water-source heat pump takes heat from the condenser water of the cold rooms and blast chiller and makes hot water at about 55 °C.
- Hot-water air coils with ducted supply give each incubation room an even air temperature.
- The yogurt base heater on the same loop brings cold-stored milk to inoculation temperature.
Selected equipment
| Model | SE-WW-55V × 1 |
|---|---|
| Heating capacity | 55 kW each, 55 kW total |
| COP | 4.7 at the data sheet's rated condition (55 °C outlet) |
| Power input | about 11.6 kW total at rated conditions |
| Rating | hot and chilled water at the same time, to 60 °C |
| Supply temperature | 55 °C |
| Storage | 2,000 L insulated tank |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TT-101 at the tank top starts the heat pump below 50 °C and stops it at 55 °C. TIC-201 holds each room at 43 °C ±0.5 K with the coil valve. TIC-202 holds the yogurt base at 43 °C. If the tank falls below 47 °C, the existing electric heaters are enabled as standby.
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 tonne of curd | – | – |
| CO₂ per year | – | – |
06Benefits
Even setting across the room
Ducted warm air keeps every cup at the same temperature, so acidity at the end of incubation is more uniform.
One machine, two jobs
The heat pump heats the rooms and helps cool the condenser water of the chilling plant.
Lower connected load
Removing room heaters frees electrical capacity for the cold chain.
Lower energy cost
Each kWh of electricity delivers about 4.7 kWh of heat at the required temperature, against well under one kWh of useful heat per kWh of fuel burnt.
Smaller electrical load
The heat pump draws roughly 1/4.7 of the power of the heaters it replaces, which frees sanctioned load and cuts demand charges.
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
- Daily curd and yogurt output and incubation time
- Room sizes, insulation and set temperature
- Cold-room and blast-chiller refrigeration capacity
- Condenser water temperature and flow
- Existing heater ratings
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
Design notes
- Humidity. Keep room relative humidity moderate to stop condensation on lids. A small exhaust fan may be needed.
- Hygiene. Use coated or stainless air coils and washable filters in the incubation room AHU.
- Electrical. About 12 kW of heat pump input at rated conditions, plus pumps and fans. Check spare sanctioned load before ordering.
- Source stream. The source must give up roughly two-thirds of the heat delivered. Confirm its flow and temperature over a full production day, and filter it before the evaporator.
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
Curd incubation rooms heated by cold-room heat
How a dairy making 15 tonnes of cup curd a day can heat its incubation rooms and yogurt base with heat taken from its cold-room condensers, instead of electric heaters.
▶Video: Waste-heat recovery heat pumps
V10 · 2–2.5 minLifting warm water from condensers, effluent and process cooling to useful heat
Video coming soon01Problem statement
- Incubation is heated with electricity. Rooms are often kept at 43 °C with electric fan heaters, which run for many hours a day.
- Uneven room temperature. Cups near heaters set faster than cups at the back. This gives variation in acidity and texture across a batch.
- Heat and cold side by side. The blast chiller next door removes the same heat again and rejects it to a cooling tower.
- Electric heating is expensive heat. Resistance heaters turn one kWh of electricity into one kWh of heat, at the full commercial tariff. A heat pump moves two to four kWh of heat for the same unit.
- Large connected load. Heater banks take a big share of the sanctioned load and push up maximum-demand charges.
02Use case
The reference plant fills 15 tonnes of set curd and yogurt a day into cups and pouches. Filled cups are incubated at 42–43 °C for 4–6 hours in two rooms, then blast-chilled and stored at 4 °C. Part of the yogurt base comes from milk held in cold storage.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Incubation rooms | 42–43 °C | 2 rooms × 8 kW fabric, air-change and product losses × 12 h | 192 |
| Cup and crate re-warming after filling | 38 → 43 °C | 15,000 kg product/day | 84 |
| Yogurt base tempering | 10 → 43 °C | 5,000 L/day from cold storage | 186 |
| Storage and pipework standing losses | – | about 5% | 23 |
| Total useful heat | 484 | ||
Averaged over 20 running hours, the heat pumps need about 24 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-WW-55V (55 kW) (SE-WW water-source heat pump) delivering 55 °C, covering the day's 484 kWh in about 8.8 running hours.
- A 2,000 L insulated storage tank decouples the heat pumps from the process peaks.
- Heat source: cold-room and blast-chiller condenser water at about 32 °C. Taking heat out of the condenser water lowers head pressure on the cold-room compressors.
- The electric room heaters and immersion heaters stays connected behind a normally closed valve as standby.
- A water-source heat pump takes heat from the condenser water of the cold rooms and blast chiller and makes hot water at about 55 °C.
- Hot-water air coils with ducted supply give each incubation room an even air temperature.
- The yogurt base heater on the same loop brings cold-stored milk to inoculation temperature.
Selected equipment
| Model | SE-WW-55V × 1 |
|---|---|
| Heating capacity | 55 kW each, 55 kW total |
| COP | 4.7 at the data sheet's rated condition (55 °C outlet) |
| Power input | about 11.6 kW total at rated conditions |
| Rating | hot and chilled water at the same time, to 60 °C |
| Supply temperature | 55 °C |
| Storage | 2,000 L insulated tank |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TT-101 at the tank top starts the heat pump below 50 °C and stops it at 55 °C. TIC-201 holds each room at 43 °C ±0.5 K with the coil valve. TIC-202 holds the yogurt base at 43 °C. If the tank falls below 47 °C, the existing electric heaters are enabled as standby.
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 tonne of curd | – | – |
| CO₂ per year | – | – |
06Benefits
Even setting across the room
Ducted warm air keeps every cup at the same temperature, so acidity at the end of incubation is more uniform.
One machine, two jobs
The heat pump heats the rooms and helps cool the condenser water of the chilling plant.
Lower connected load
Removing room heaters frees electrical capacity for the cold chain.
Lower energy cost
Each kWh of electricity delivers about 4.7 kWh of heat at the required temperature, against well under one kWh of useful heat per kWh of fuel burnt.
Smaller electrical load
The heat pump draws roughly 1/4.7 of the power of the heaters it replaces, which frees sanctioned load and cuts demand charges.
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
- Daily curd and yogurt output and incubation time
- Room sizes, insulation and set temperature
- Cold-room and blast-chiller refrigeration capacity
- Condenser water temperature and flow
- Existing heater ratings
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
Design notes
- Humidity. Keep room relative humidity moderate to stop condensation on lids. A small exhaust fan may be needed.
- Hygiene. Use coated or stainless air coils and washable filters in the incubation room AHU.
- Electrical. About 12 kW of heat pump input at rated conditions, plus pumps and fans. Check spare sanctioned load before ordering.
- Source stream. The source must give up roughly two-thirds of the heat delivered. Confirm its flow and temperature over a full production day, and filter it before the evaporator.
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.