1. HWAT Revival
Special focus on hospitals
Hygiene Flexibility
Economy

2. Requirements for Hot Water Systems in hospitals
Hygiene & Comfort
Flexibility
Economy

3. Available systems for Hot Water Distribution
The conventional, expensive solution:
the Recirculation System
2. The intelligent, economic alternative:
the Hot Water Temperature Maintenance
System

4. Mode of operation of Raychem’s Hot Water Temperature Maintenance system
Insulation
The water heater heats the water!
The heating cable compensates for the heat losses and supplies heat where it is needed.
Self-regulating heating cable

5. 35 Years of Experience and competence
The self-regulating heating cable was invented by Raychem in 1976
Installed in over 300,000 buildings
Over 1000 km of temperature maintenance cable are installed each year
Some famous examples:
Heathrow, Charles de Gaulle Airport
Eiffel Tower
Royal Opera House London
Numerous hospitals

6. Requirements for Hot Water Systems in hospitals
Hygiene & Comfort
Flexibility
Economy

7. Comfort Hot water at tap No maintenance and servicing
The demands made on hot water supply systems concentrate, on the one hand, on the comfort of the user (patient), in other words having immediate hot water at the tap ...
….and, on the other hand, on the convenience to the operator (hospital) by avoiding time-consuming and expensive maintenance and servicing of the system (fewer pipes, control valves and pumps).
Hot water at tap
No maintenance and servicing

8. Hygiene – legionella in the Hot Water Distribution System
Legionella bacteria propagate at:
Low flow rates, in oversized pipes
Hot water temperatures below 60°C
Corrosion and contamination, biofilm
Legionella may remain trapped in the biofilm and may therefore resist temperature shock or even treatment with disinfectant.

9. Hygiene: DVGW requirements for the construction of a hygienic Hot Water Distribution System
5.1 Drinking water heating systems must be designed as small as possible.
Recirculation System with return pipe
Hot water Temperature Maintenance System
The hot water temperature maintenance system has fewer pipes, less water volume, less heat loss and therefore presents a lower risk of bacterial problems.

10. DVGW requirement 5.2 Drinking water heater
The cold water inlet ... must be designed to avoid .. a large mixing zone h
Recirculation
Recirculation System with return pipe
Hot Water Temperature Maintenance System
The water heater volume is used efficiently with the hot water temperature maintenance system because there is no drinking water return pipe
The zone between cold and hot is not affected

11. Advantages of the hot water temperature maintenance system in terms of hygiene: legionella prevention
Shortest pipe network of all central hot water systems (“half pipe length”)
Guaranteed high temperature throughout the system over the entire length
No unheated zones
Temperature maintenance
Possible as far as tap point
Temperature increase of up to 70°C possible
Efficient use of the water heater
No return pipe
Renewal of water in the pipe network
Pipe volume is 100% renewed with each tapping process because water flows in one direction only

12. The hot water temperature maintenance system provides comfort and a hygienic hot water supply
Shortest drinking water heating system
Most efficient use of drinking water heater
Guaranteed high temperature throughout the system over the entire length
Legionella prevention
Hygiene & Comfort

13. Requirements for hot water systems in hospitals
Hygiene & Comfort
Flexibility
Economy

14. Space-saving and flexible: Simple installation for an extension or new building
One pipe (including insulation) less
High degree of flexibility when making modifications to the pipe network:
Adaptations regardless of hydraulic alignment!
Construction, during renovation work, can be split in sections (time factor) without influence on complete hot water network
Self-regulating heating cable can be easily shortened or lengthened, in the case of an extension

15. Flexibility: Leasing to third parties
Because of cost pressure there is an increasing trend towards leasing consulting rooms to established specialists or specialist institutions
Simple measurement of the hot water consumption is possible by means of conventional water meters at any point with the hot water temperature maintenance system
This in turn allows leasing by station or room because of accurate, separate cost invoicing.

16. Flexibility: Complementary to the recirculation system
Hot Water Temperature Maintenance system can be complementary to the recirculation system, where this is sensible
Heating cable

17. The Hot Water Temperature Maintenance System offers enormous flexibility!
For extensions
In case of modifications
Space saving
For subletting
Flexibility

18. Requirements for hot water systems in hospitals
Hygiene & Comfort
Flexibility
Economy

19. Savewatt economy comparison between recirculation and Hot Water Temperature Maintenance
Comparison on the basis of a real
calculation in a hospital equipped
with recirculation

20. Savewatt calculation- Model Hospital East Wing Basic data
Recirculation
Stainless steel pipes
Supply: 363 m
Return: 354 m
Mineral wool shell insulation (thickness according to german standards)
Fittings:
Circulation pump 1 off
Pump shutoff valves 2 off
Line control valves 12 off
Shutoff valves 12 off
Temperature maintenance system
Stainless steel pipes
Supply: 363 m
Mineral wool shell insulation (thickness according to german standards)
4 heating circuits
HWAT-R 375 m
Switch cabinet SBS-06-HV-ECO-10
RayClic-CE off
RayClic-T off
Fastening materials
Stammdaten not yet updated with recent costs: Rohre, etc

21. Savewatt calculation – Model Hospital East Wing Basic data
Energy prices:
Natural gas: Euro/kWh
Electricity: Euro/kWh
Thermal parameters
Water heater temperature
Output: 60°C
Input: 55°C
Maintenance temperature of Hot Water Maintenance System: 55°C
Ambient temperature: 18 – 22 °C
Efficiency rating
Recirculation: 72%
Efficiency rating of water heater: 90%
Yearly efficiency rating of total warm water system: 80%
Temperature Maintenance System: 76%
Efficiency rating of water heater : 95%
Yearly efficiency rating of total warm water system : 80%

22. Operating costs: only 36% energy demand and 10% lower operating costs
Energy efficiency ratings (boiler x total warm water supply)
Recirculation: %
Hot water temperature maintenance system: %

23. Depreciation 10% yearly saving on capital and operating costs
Basis of calculation
20 years usage
Yearly interest rate 5 %
Recirculation System
Investment €
Annual capital costs €
Annual oper. costs €
Total per annum €
Hot Water Temperature Maintenance System
Investment €
Annual capital costs €
Annual oper. costs €
Total per annum €

24. The Hot Water Temperature Maintenance System is the more economic choice – in every respect!
The investment costs for the hot water temperature maintenance system are slightly lower than in the recirculation system
Prices of metal pipes, such as copper, increased sharply last year. The use of expensive pipes provides even a greater investment cost advantage
The operating costs are lower than in the recirculation system
If the energy price for water heating is approx. 30% of the electricity price, the costs are equalised if the building is insulated according to the german standards
An increase in efficiency means: Thicker insulation, lower heat losses, lower operating costs!
Less maintenance and servicing due to the one-pipe system (fewer pipes, no control valves or pumps)

25. The Hot Water Temperature Maintenance System is economical and efficient
Low investment costs
Lower energy consumption costs
No maintenance or servicing costs
Economy