CPD Figure 3; Carbon Saving Low-temperature system vs High-temperature system Specication 3* Rinnai N1600 t = 50 3* Rinnai N1600 t = 33 3* Rinnai N1600 t = 33 Reduced mass ow rate Max Heat Input (kW) Max heat output (kW) Efciency (Gross) 1st hour ow rate @ 50C rise (l/hr) Storage/Cylinder (L) Continuous ow rate (l/hr) Peak usage periods (hr) Number of peak usage periods Heating consumption (kW) Storage loss (kWh) Secondary return system heat loss per hour (kW) Efciency curve Input for secondary system (kW) Secondary system operating time (hr) Reheat of secondary return (kWh/day) Consumption per peak period (kWh) Total consumption per day (kWh) Consumption per week (kWh) Annual consumption (kWh) Gas price (/kWh) Running annum cost () Annual Carbon emission in kg 2022 to 2025 Annual Carbon Emission in kg 2025 to 2030 with 20 % Green Hydrogen Percentage annual Carbon savings (Ref to option 1 - high temp) 175 168 96.00% 2880 0 2880 1 3 175 0 115.5 111 96.00% 2880 0 2880 1 3 115.5 0 72.6 69.6 96.00% 1800 0 1800 1 3 72.6 0 10 95.00% 10.5 21 220.5 175 745.5 5218.5 271362 0.045 12211.3 7 95.00% 7.3 21 154.7 115.5 501.23 3508.6 182450.2 0.045 8210.2 7 95.00% 7.3 21 154.7 72.6 372.5 2607.7 135603.4 0.045 6102.1 56986 38314.5 28476.7 45588.8 30651.6 22781.3 0 32.77% 50.03% References 1 For more details on RINNAI products visit www.rinnaiuk.com Pomianowski, M. Z., Johra, H., Marszal-Pomianowska, A., & Zhang, C. (2020). Sustainable and energy-efcient domestic hot water systems: A review. Renewable and Sustainable Energy Reviews, 128, 109900. 2 Yang, X., Li, H., & Svendsen, S. (2016). Energy, economy, and exergy evaluations of the solutions for supplying domestic hot water from low-temperature district heating in Denmark. Energy conversion and management, 122, 142-152. 3 July 2021, Turning on energy savings for hot water: instantaneous hot water, CIBSE Journal 54 September 2021 www.cibsejournal.com https://www.cibsejournal.com/ uncategorized/turning-onenergy-savings-for-hot-waterinstantaneous-hot-water 4 Cloutman-Green, Elaine, et al. Controlling Legionella pneumonia in water systems at reduced hot water temperatures with copper and silver ionization. American journal of infection control 47.7 (2019): 761766. 5 Demyanova, O. V., Badrieva, R. R., & Andreychenko, I. S. Features of lean manufacturing in the energy sector. 6 Dentz, J., Ansanelli, E., Henderson, H., & Varshney, K. (2016). Control Strategies to Reduce the Energy Consumption of Central Domestic Hot Water Systems (No. NREL/SR-550064541; DOE/GO-102016-4703). National Renewable Energy Lab. (NREL), Golden, CO (United States). 7 Lutz, J. (2005). Estimating Energy and Water Losses in Residential Hot Water Distribution Systems (No. LBNL-57199). Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US). 8 The Engineering toolbox Uninsulated Cylinder or Pipe https://www.engineeringtoolbox. com/ Advertisement Feature p54.CIBSEMagSept21.indd 54 23/08/2021 11:45