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1 This presentation is posted for public use. ACEEE does not endorse any product or service. ACEEE accepts no responsibility for any facts or claims this presentation may contain.

2 ACEEE, Hot Water Forum may 2012 Hot Water - in Denmark By Flemming Schrøder Hot water consumption and energy consumption for hot water - is increasing. Never had so many taking so many baths. - That is positive for the health and wellbeing. But hot water systems have the highest energy consumption in the time we do not use it, and that we can do something about. 1

3 ACEEE, Hot Water Forum may 2012 Hot Water - in Denmark ALECTIA - consulting engineers, Global presence, 700 employees, 100 years the Snow belt area Denmark Copenhagen 2

4 Hot Water - in Denmark ACEEE, Hot Water Forum May 2012 Free download!!! Hot Water Research report Measurement of consumption and heat loss in circulation pipe systems 200 pages, published in 2009 Participants: State Building Research Institute by Niels Christian Bergsø, senior researcher Technical University of Denmark by Benny Bøhm, professoer, ALECTIA - consulting engineers by Flemming Schrøder, engineer 3

5 Water consumption, in Danish households 375 mill. m 3 water 70m 3 ~18,500gallon/pers. in 1980s Danish statistics 245 mill. M 3 water 45m 3 ~12,000 gallon/pers. in 2000s 3

6 Expected trend in hot water consumption in Danish households Årlig vandforbrug i m3/person i boliger KOLDT VAND VARMT VAND Cold Water Hot Water /50? ~ ? 4

7 200PJ Denmark's annual energy consumption in households 50PJ Splitting up energy for hot water 200PJ/år Recovered losses 50PJ/år Hot water Electricity From cold to hot Room heating Loss Hot water energy in housholds in DK: 50PJ ~ 250W /h *person, every hour, every day 5

8 Measurement of water and heat consumption Hot water tank Hot water kwh > < Circulation pump > Primary Meters m 3 kwh Sensors kwh > m 3 / kwh Secondary meters Cold water Heating > > < 7

9 Examples from the report Fotos of building diagrams of the piping schedules consumptions temperatures 8

10 Extract of measurements of 35 different hot water circulation systems Measurements in 2008: (HWRR 24 systems) 10 blocks of flats 2 town house 2 family houses 6 schools 4 office buildings Hot Water Research report Measursments in 2004: (prv. HWRR 11 systems) 6 blocks of flats 1 office buildings 4 hospitals A total 35 hot water systems 9

11 Target poins and results Target points 1. Heating consumptions for hot water (MWh/year) 2. Heat loss from pipes and tanks (MWh/year) 3. Use of cold and hot water (Gall/year) 4. Pipe length circulation (m) or (Feet) 5. Cooling of the district heating ( o F) 6. Operating time (hours/year) 2. Hot water tank Results 7. Energy efficiency of hot water systems (%) 8. Loss per meter pipe (W/m) 9. Part of the hot water consumption in relation to the cold water consumption (%) Hot water residence time in the hot water tank (hours/days) 11. Electricity for circulation pump per meter circulation line (W/m) 6. 10

12 loss T N C H E = N/T x 100% 7. Energy efficiency = E % Measurements in 2008: 10 blocks of flats 30-77% 2 town house 42-61% 2 family houses 35% 6 schools 8-46% 4 office buildings 11-32% Measurements in 2004: 6 blocks of flats 18-42% 1 office buildings 8% 4 hospitals 7-40% 11

13 ACEEE, Hot Water Forum may 2012 Hot Water - in Denmark 8. Heat loss per meter pipe 10 blocks of flats 6-21W/m 2 family houses 5-10W/m 6 schools 5-33W/m 4 office buildings 10-18W/m H Water gallon T 9. Hot water consumption in relation to total water consumption 10 blocks of flats ~33%(average) 2 family houses 31-34% 6 schools 5-21% 4 office buildings % (H/T x100%) 12

14 5. Cooling of heating - forward temp.~ 180 o F 4 blocks of flats 36-45grd. C ~ o F 4 blocks of flats 19-27grd. C ~ o F 2 blocks of flats 10-11grd. C ~ 50 o F ~135 o F ~180 o F Circulation ~120 o F ~130 o F Domestic water ~55 o F District heating ~70 o F Hot water tank/exchanger 13

15 Piping - saving energy Pipe-in-pipe Uponor-ecoflex Viega A/S Inliner Golan Plastic Produts - PEX-pipes- Denmark 14

16 Exchanger-unit for hot water Exchanger-unit for Exchanger-unit for hot water and heating Germina Termix / Danfoss Group: Flat stations Grundfos: Pump with thermal sensor. Remember when using hot water 15

17 Renovation of hot water systems with reduce pipe length with 1 mile, and the energy loss with 50% 100 flat building from 1970 Old pipes New pipes well-insulated Renov. New water pipe system 16

18 Conclusions and recommendations for saving energy in Hot Water systems A. There is high heat loss in large circulation system B. Large circulation systems with low water consumption gives high temperature in heating returns C. Keep hot water taps close to each other and close to heaters, avoid circulation pipes. D. Buildings with low hot water consumption and long circulation pipes consider heating up water with local electricity heaters E. In large residential buildings, -consider solution with centralized or decentralized hot water production (flat stations) F. Insulate pipes and valves carefully G. Reduce the length of the circulation pipes and the dimension. Use new types of pipes and pumps in connection with the renovation of pipe systems H. Time control of the circulation pump 17

19 References: ALECTIA A/S: tel: Flemming Schrøder: tel: State Building Research Institute (Sbi): Technical University of Denmark (DTU) Danish statistics: Danfoss A/S Denmark: Grundfos A/S Denmark: Viega A/S Denmark: Wavin A/S Denmark: Golan Plastic Produts aps: Thank you hope it might give you ideas for saving energy in Hot Water systems 18