Bakery proofers and crate washers on heat pumps
How a bakery making 40,000 loaves a day can heat its proofers and crate washer with heat pump hot water instead of LPG.
▶Video: Process hot water for food, dairy and beverages
V02 · 2–2.5 minPasteurisers, CIP, cooking and washing on stored hot water instead of boiler steam
Video coming soon01Problem statement
- Proofers need warmth and humidity. Proofers run at about 38 °C with high humidity, using gas or electric heaters plus steam or water humidifiers.
- Crate washer burners. Crate washers often have their own gas burner, which runs whenever the washer runs.
- Several small heat users. Proofers, crate washer and tray washing each have their own heater, which adds up to a lot of fuel.
- Losses between fuel and process. Burning LPG 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 plant makes about 40,000 loaves of bread and buns a day over two shifts. Dough is proofed in two tray proofers at 38 °C and 80–85% humidity before the tunnel oven. About 8,000 delivery crates come back each day and are washed before reuse.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Proofers, heating and humidification | 38 °C, 80–85% RH | 2 proofers × 12 kW × 16 h | 384 |
| Crate washer | 60 °C | 8,000 crates × 0.5 L = 4,000 L/day, 30 → 60 °C, 30% tank losses | 181 |
| Tray and pan washing | 60 °C | 3,000 L/day, 30 → 60 °C | 104 |
| Storage and pipework standing losses | – | about 5% | 33 |
| Total useful heat | 703 | ||
Averaged over 18 running hours, the heat pumps need about 39 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-SHT-50C (50 kW) (SE-SHT cascade heat pump) delivering 70 °C, covering the day's 703 kWh in about 14.1 running hours.
- A 1,500 L insulated storage tank decouples the heat pumps from the process peaks.
- The LPG-fired heaters and crate washer burner stays connected behind a normally closed valve as standby.
- Hot-water coils in each proofer replace the gas or electric heaters. A warm-water humidifier fed from the same loop adds moisture.
- The crate washer tank is heated through a plate exchanger instead of its burner.
- Tray and pan washing water is heated from the same tank.
Selected equipment
| Model | SE-SHT-50C × 1 |
|---|---|
| Heating capacity | 50 kW each, 50 kW total |
| COP | 2.6 at A20 °C / W90 °C (data sheet T1) |
| Power input | about 18.6 kW total at rated conditions |
| Rating | cascade R410A + R515B, rated 90 °C, 95 °C maximum |
| Supply temperature | 70 °C |
| Storage | 1,500 L insulated tank |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TT-101 at the tank top starts the heat pumps below 65 °C and stops them at 70 °C. TIC-201 holds each proofer at 38 °C, with a separate humidity controller. TIC-202 and TIC-203 hold washer tanks at 60 °C. If the tank falls below 62 °C, the existing 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 1,000 loaves | – | – |
| CO₂ per year | – | – |
06Benefits
Even proofing
Hot-water coils give steady, even proofer temperature, which helps loaf volume and shape.
No open flames on washers
Crate washers run without gas burners.
One utility for small loads
A single hot-water loop replaces several small gas and electric heaters.
Lower energy cost
Each kWh of electricity delivers about 2.6 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
- Daily output and shift pattern
- Number and size of proofers, set temperature and humidity
- Crates washed per day and washer type
- Tray and pan washing volumes
- Current LPG and electricity use
- 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
- Proofer humidity. Humidity control is as important as temperature. Keep the humidifier and its controls separate from the heating coil.
- Crate washer detergent. Washer water carries detergent and dough. Use a cleanable plate exchanger with a strainer.
- Electrical. About 19 kW of heat pump input at rated conditions, plus pumps and fans. Check spare sanctioned load before ordering.
- Winter output. The SE-SHT cascade gives about 80% of rated output at 7 °C ambient and still runs at −20 °C. Size on the coldest design day for northern sites.
- Water quality. Scale forms quickly above 60 °C. Use softened make-up and keep the heat pump loop closed, with process fluids on the far side of an exchanger or coil.
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.
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Bakery proofers and crate washers on heat pumps
How a bakery making 40,000 loaves a day can heat its proofers and crate washer with heat pump hot water instead of LPG.
▶Video: Process hot water for food, dairy and beverages
V02 · 2–2.5 minPasteurisers, CIP, cooking and washing on stored hot water instead of boiler steam
Video coming soon01Problem statement
- Proofers need warmth and humidity. Proofers run at about 38 °C with high humidity, using gas or electric heaters plus steam or water humidifiers.
- Crate washer burners. Crate washers often have their own gas burner, which runs whenever the washer runs.
- Several small heat users. Proofers, crate washer and tray washing each have their own heater, which adds up to a lot of fuel.
- Losses between fuel and process. Burning LPG 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 plant makes about 40,000 loaves of bread and buns a day over two shifts. Dough is proofed in two tray proofers at 38 °C and 80–85% humidity before the tunnel oven. About 8,000 delivery crates come back each day and are washed before reuse.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Proofers, heating and humidification | 38 °C, 80–85% RH | 2 proofers × 12 kW × 16 h | 384 |
| Crate washer | 60 °C | 8,000 crates × 0.5 L = 4,000 L/day, 30 → 60 °C, 30% tank losses | 181 |
| Tray and pan washing | 60 °C | 3,000 L/day, 30 → 60 °C | 104 |
| Storage and pipework standing losses | – | about 5% | 33 |
| Total useful heat | 703 | ||
Averaged over 18 running hours, the heat pumps need about 39 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-SHT-50C (50 kW) (SE-SHT cascade heat pump) delivering 70 °C, covering the day's 703 kWh in about 14.1 running hours.
- A 1,500 L insulated storage tank decouples the heat pumps from the process peaks.
- The LPG-fired heaters and crate washer burner stays connected behind a normally closed valve as standby.
- Hot-water coils in each proofer replace the gas or electric heaters. A warm-water humidifier fed from the same loop adds moisture.
- The crate washer tank is heated through a plate exchanger instead of its burner.
- Tray and pan washing water is heated from the same tank.
Selected equipment
| Model | SE-SHT-50C × 1 |
|---|---|
| Heating capacity | 50 kW each, 50 kW total |
| COP | 2.6 at A20 °C / W90 °C (data sheet T1) |
| Power input | about 18.6 kW total at rated conditions |
| Rating | cascade R410A + R515B, rated 90 °C, 95 °C maximum |
| Supply temperature | 70 °C |
| Storage | 1,500 L insulated tank |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TT-101 at the tank top starts the heat pumps below 65 °C and stops them at 70 °C. TIC-201 holds each proofer at 38 °C, with a separate humidity controller. TIC-202 and TIC-203 hold washer tanks at 60 °C. If the tank falls below 62 °C, the existing 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 1,000 loaves | – | – |
| CO₂ per year | – | – |
06Benefits
Even proofing
Hot-water coils give steady, even proofer temperature, which helps loaf volume and shape.
No open flames on washers
Crate washers run without gas burners.
One utility for small loads
A single hot-water loop replaces several small gas and electric heaters.
Lower energy cost
Each kWh of electricity delivers about 2.6 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
- Daily output and shift pattern
- Number and size of proofers, set temperature and humidity
- Crates washed per day and washer type
- Tray and pan washing volumes
- Current LPG and electricity use
- 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
- Proofer humidity. Humidity control is as important as temperature. Keep the humidifier and its controls separate from the heating coil.
- Crate washer detergent. Washer water carries detergent and dough. Use a cleanable plate exchanger with a strainer.
- Electrical. About 19 kW of heat pump input at rated conditions, plus pumps and fans. Check spare sanctioned load before ordering.
- Winter output. The SE-SHT cascade gives about 80% of rated output at 7 °C ambient and still runs at −20 °C. Size on the coldest design day for northern sites.
- Water quality. Scale forms quickly above 60 °C. Use softened make-up and keep the heat pump loop closed, with process fluids on the far side of an exchanger or coil.
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.