Hospital laundry and CSSD hot water from heat pumps
How a 500-bed hospital can supply its CSSD washers and linen laundry with 40–75 °C hot water from heat pumps, and what it saves against a diesel-fired boiler.
▶Video: Sanitary and commercial hot water
V14 · 2–2.5 minHotels, hospitals, kitchens and laundries
Video coming soon01Problem statement
- Disinfection needs hot water. Linen must be washed hot enough for thermal disinfection, about 71 °C for several minutes, and CSSD washers need hot fill water for each cycle.
- Boiler for moderate temperatures. Most of the laundry and CSSD load is below 75 °C, yet it is met from a steam boiler with its losses.
- Washers heat their own water. Washer-disinfectors fed with cold water heat it with built-in electric elements, which lengthens cycles.
- 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 hospital has 500 beds, a central sterile services department with six washer-disinfectors and an in-house laundry washing about 1,500 kg of linen a day. Both run seven days a week.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Linen washing | 25 → 75 °C | 1,500 kg/day × 12 L/kg hot water, 25 → 75 °C | 1,045 |
| CSSD washer-disinfector fill | 25 → 60 °C | 6 washers × 15 cycles × 60 L, 25 → 60 °C | 219 |
| CSSD pre-wash and manual sinks | 25 → 45 °C | 2,000 L/day, 25 → 45 °C | 46 |
| Storage and pipework standing losses | – | about 5% | 66 |
| Total useful heat | 1,376 | ||
Averaged over 20 running hours, the heat pumps need about 69 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
- 3 × SE-SHT-25C (75 kW total) (SE-SHT cascade heat pump) delivering 85 °C, covering the day's 1,376 kWh in about 18.4 running hours.
- A 2,500 L insulated storage tank decouples the heat pumps from the process peaks.
- The diesel-fired steam boiler stays connected behind a normally closed valve as standby.
- Heat pumps make 80–85 °C water into a storage tank that fills the laundry washer-extractors at 75 °C.
- CSSD washer-disinfectors take 60 °C fill water through a PHE, so their own elements only lift the final thermal disinfection stage to 90 °C.
- Pre-wash sinks take mixed water at 40–45 °C, which avoids fixing proteins onto instruments.
- The tank covers the morning laundry peak so the heat pumps run steadily.
Selected equipment
| Model | SE-SHT-25C × 3 |
|---|---|
| Heating capacity | 25 kW each, 75 kW total |
| COP | 2.6 at A20 °C / W90 °C (data sheet T1) |
| Power input | about 27.9 kW total at rated conditions |
| Rating | cascade R410A + R515B, rated 90 °C, 95 °C maximum |
| Supply temperature | 85 °C |
| Storage | 2,500 L insulated tank |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TT-101 at the top of the tank starts the heat pumps below 78 °C and stops them at 84 °C. TIC-201 holds the laundry feed at 75 °C, TIC-202 holds CSSD fill at 60 °C and a thermostatic valve limits pre-wash water to 45 °C. The boiler stays 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 100 kg linen | – | – |
| CO₂ per year | – | – |
06Benefits
Shorter CSSD cycles
Washers start with 60 °C water, so their heating stages finish sooner and throughput rises.
Reliable thermal disinfection
Stored 75 °C water lets linen reach disinfection temperature quickly and consistently.
Correct pre-wash temperature
Blended water at 40–45 °C cleans instruments without baking on blood and tissue.
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.
Built-in redundancy
Several machines share the load. If one is serviced, the others and the storage carry most of the day, with the existing heater in reserve.
07Engineering pointers
Site data to collect
- Linen washed per day and machine schedule
- CSSD washer models, cycles per day and fill volumes
- Current boiler fuel use for laundry and CSSD
- Water hardness and purified water arrangement
- Plant room space
- 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
- Pre-wash temperature limit. Instrument pre-wash water must stay below about 45 °C, since hotter water fixes proteins. Fit a thermostatic limiter on CSSD sinks.
- Water quality. CSSD final rinse needs purified water. The heat pump system supplies only the earlier wash stages unless the loop is built for purified water.
- Lint and scale. Soften laundry feed water and keep lint filters on any heat recovery from laundry drains.
- Electrical. About 28 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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Hospital laundry and CSSD hot water from heat pumps
How a 500-bed hospital can supply its CSSD washers and linen laundry with 40–75 °C hot water from heat pumps, and what it saves against a diesel-fired boiler.
▶Video: Sanitary and commercial hot water
V14 · 2–2.5 minHotels, hospitals, kitchens and laundries
Video coming soon01Problem statement
- Disinfection needs hot water. Linen must be washed hot enough for thermal disinfection, about 71 °C for several minutes, and CSSD washers need hot fill water for each cycle.
- Boiler for moderate temperatures. Most of the laundry and CSSD load is below 75 °C, yet it is met from a steam boiler with its losses.
- Washers heat their own water. Washer-disinfectors fed with cold water heat it with built-in electric elements, which lengthens cycles.
- 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 hospital has 500 beds, a central sterile services department with six washer-disinfectors and an in-house laundry washing about 1,500 kg of linen a day. Both run seven days a week.
| Heat user | Process temp. | Basis | Heat, kWh/day |
|---|---|---|---|
| Linen washing | 25 → 75 °C | 1,500 kg/day × 12 L/kg hot water, 25 → 75 °C | 1,045 |
| CSSD washer-disinfector fill | 25 → 60 °C | 6 washers × 15 cycles × 60 L, 25 → 60 °C | 219 |
| CSSD pre-wash and manual sinks | 25 → 45 °C | 2,000 L/day, 25 → 45 °C | 46 |
| Storage and pipework standing losses | – | about 5% | 66 |
| Total useful heat | 1,376 | ||
Averaged over 20 running hours, the heat pumps need about 69 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
- 3 × SE-SHT-25C (75 kW total) (SE-SHT cascade heat pump) delivering 85 °C, covering the day's 1,376 kWh in about 18.4 running hours.
- A 2,500 L insulated storage tank decouples the heat pumps from the process peaks.
- The diesel-fired steam boiler stays connected behind a normally closed valve as standby.
- Heat pumps make 80–85 °C water into a storage tank that fills the laundry washer-extractors at 75 °C.
- CSSD washer-disinfectors take 60 °C fill water through a PHE, so their own elements only lift the final thermal disinfection stage to 90 °C.
- Pre-wash sinks take mixed water at 40–45 °C, which avoids fixing proteins onto instruments.
- The tank covers the morning laundry peak so the heat pumps run steadily.
Selected equipment
| Model | SE-SHT-25C × 3 |
|---|---|
| Heating capacity | 25 kW each, 75 kW total |
| COP | 2.6 at A20 °C / W90 °C (data sheet T1) |
| Power input | about 27.9 kW total at rated conditions |
| Rating | cascade R410A + R515B, rated 90 °C, 95 °C maximum |
| Supply temperature | 85 °C |
| Storage | 2,500 L insulated tank |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TT-101 at the top of the tank starts the heat pumps below 78 °C and stops them at 84 °C. TIC-201 holds the laundry feed at 75 °C, TIC-202 holds CSSD fill at 60 °C and a thermostatic valve limits pre-wash water to 45 °C. The boiler stays 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 100 kg linen | – | – |
| CO₂ per year | – | – |
06Benefits
Shorter CSSD cycles
Washers start with 60 °C water, so their heating stages finish sooner and throughput rises.
Reliable thermal disinfection
Stored 75 °C water lets linen reach disinfection temperature quickly and consistently.
Correct pre-wash temperature
Blended water at 40–45 °C cleans instruments without baking on blood and tissue.
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.
Built-in redundancy
Several machines share the load. If one is serviced, the others and the storage carry most of the day, with the existing heater in reserve.
07Engineering pointers
Site data to collect
- Linen washed per day and machine schedule
- CSSD washer models, cycles per day and fill volumes
- Current boiler fuel use for laundry and CSSD
- Water hardness and purified water arrangement
- Plant room space
- 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
- Pre-wash temperature limit. Instrument pre-wash water must stay below about 45 °C, since hotter water fixes proteins. Fit a thermostatic limiter on CSSD sinks.
- Water quality. CSSD final rinse needs purified water. The heat pump system supplies only the earlier wash stages unless the loop is built for purified water.
- Lint and scale. Soften laundry feed water and keep lint filters on any heat recovery from laundry drains.
- Electrical. About 28 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.