HVAC Solutions Variable Volume Systems

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Good Heat Network Practice

Heating systems shall be operated to ensure that a satisfactory thermal indoor environment is attained, with the lowest possible energy consumption and the avoidance of unnecessary energy wastage.

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Topics

• Buildings on Drugs

• Fundamental Change– Temperature & Pressure

• What are the obstacles and solutions

• Return Temperatures

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

65C return temperature =

120 beats per minute

40C body temperature

Tel: 0044(0) 01483 77 1910 80Designing 65 and commissioning low carbon variable volume systems Web: www.sav-systems.com

£ Significant energy savings £

40C return temperature =

60 beats per minute

36C body temperature

Tel: 0044(0) 01483 77 1910 70Designing 40 and commissioning low carbon variable volume systems Web: www.sav-systems.com

Emphasis

Temperature control & Pressure control

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Danish District Heating Experience

The adoption of low carbon technologies in Denmark is being driven by the operators of district heating schemes, combined with high carbon taxes.

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Continuous Monitoring of Return Temperatures and Calculating Delta T

Ultrasonic heat meter

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Demand Reduction

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Efficiency Rebate

Ultrasonic heat meter

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Distribution Heat Losses

Wast

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Making better use of our energy resources

50 30

70 40

80 65

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Supply Side - Heating Plant

• Primary energy efficiencies 80/60°C

Heat Pump/Condensing Boiler

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Supply Side – Thermal Stores

• Primary energy efficiencies 80/60°C 푃 = 4.2 ∙ 푄 ∙ ∆푡

Energy storage

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Supply Side – CHP

AM12/2013 – Combined heat and power for buildings “Normally, a fixed flow temperature is required from the CHP unit, and the mixing circuit should be used to control the flow temperature off the unit by injecting flow water into the return as required.”

CHP System

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Supply Side - District Heating Plant

• Primary energy efficiencies 70/40C

Condensing boiler, Heat Pump

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Supply Side – Central Plant – Low Load (20%)

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Supply Side – Central Plant – High Load (100%)

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Low Return Under All Load Conditions

Design Condition -4°C 70/40°C

Shoulder Months 60/40°C

Summer 55/40°C

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Flow Temperature Function of Return

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Demand Side – Radiator Balancing

55°C

50°C 35°C 25°C 30°C

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Demand Side - Fan Coil Systems

Variable flow by-pass

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Bypasses

•Minimum flow

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

High Dissipation Underfloor Heating!

Features: • 85 w/m2 at mean temperature of 32.4ºC

Benefits: • Faster acting underfloor heating with low system return temperatures

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

DHW Cylinders

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Central DHW Generation Heat loss. Standard thermostat Danfoss TPV

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Domestic Hot Water

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com

Conclusions Focus on Return Temperature

Tel: 0044(0) 01483 77 1910 Designing and commissioning low carbon variable volume systems Web: www.sav-systems.com