SOLAR THERMAL WATER HEATING SIMON WHELAN
Solar Thermal Water Heating Topics Solar Thermal Water Heating Types of panels Flat plates Vacuum tubes Cylinders Cost/Payback
Solar Water Heating- uses Domestic water heating - High grade heat from the sun - Mostly showers and washing Dishwashers, washing machine often heated separately – need direct hot feed appliances Space Heating Support Large capital and material investment Most energy in Summer when needed least Better bang for heating buck in insulation and design
Water heating - % of your energy use
How do solar panels work 3 energy flows - heat collection, heat loss, heat transfer
Domestic Solar Water Heating A. Solar panels B. Pump Station C. Cylinder D. Boiler
4 main things to consider 1.Orientation South is best, Anywhere between SW – SE OK East West requires specific system 2. Occupancy = Water Usage =Size of Cylinder - 50 L of hot water per person a day 3. Type of Panel – Flat Plate or evacuated tube 4. Size of Array
Two main Types of Panel; Flat plate panels -In Roof -On Roof Vacuum tube -direct contact water heating -Single-walled vacuum tube with heat pipes -Twin-walled vacuum tube with heat pipe
Flat Panel – In roof - Galway
Flat Panel – In roof - Celbridge Flashing to weather proof Very Similar to Velux Windows 10
Flat Panel – In roof - Celbridge Install roof covering (slates/Tiles) around flashing No wind load issues Pipework runs directly in to the attic space – no roof penetration issues 11
Flat Panel – on roof 2 fixing options - Bolts – Slate roof - Bracket – Tile roof 12
Flat Panel – on roof - Delgany Use of brackets on tile roof Alumium Profile to support panels 13
Advantages of Flat plates Durable option – long life time 25 -35 years Better Aesthetics – great looking panel flashed into roof Can take up less surface area on roof than evacuated tubes
Vaccuum tubes: Bray 15
Vaccuum tubes –Heat pipes
Frame on roof contains tubes – mutiple panels in series Multiple panels in in Bray- straight connection. 17
Flat roof: Watch the wind load 18
Ground mount: Long Pipe Run – inefficiencies introduced 19
Typically more efficient than FP per m2 of Aperture area ADVANTAGES OF TUBES Typically more efficient than FP per m2 of Aperture area Totally insulated – no heat loss Passively tracking – Incident Angle Modifier Lower thermal mass Lighter to lift into place Sit on top of slates – easier to retrofit Double wall vacuum tubes are potentially a very sustainable product in Ireland. DISADVANTAGES Aesthetics Maintenance required after 15 to 20 yrs but modular
Pump station installation Attic installation Controller in accessible position Expansion Vessel installed below pipe line Blow off vessel 3 port valve (HT) to heat dump Need power point – fused circuit in area. 21
Solar Controller: Resol BS3 Temperature displays Controls Pump Frost-protection Store temperature limitation Excess heat dissipation to radiator or can be after heat function 22
Solar Cylinders Dual/Triple coil Cylinders Tall = better stratification Insulation thickness 50mm min Copper or Stainless steel High efficiency solar coil - 20% of panel surface area Two sensor ports for controller temperature probes Consider weight of larger cylinder!
Choosing a System – Look for Energy yield not Efficiency Sun is a moving energy source. Panels differ Zero loss efficiency describes efficiency at normal incidence - Noon Not sufficient to describe performance accurately.
Choosing a System – Look for Energy yield not Efficiency Incident Angle Modifier Energy yield of system Not efficiency of panel TSol/DEAP/Test results Establish Cost/Benefit
Costs and Payback How long is a piece of string? Typical cost range from E4500 – E5500 installed Grant aid brings cost to 3500 – 4000 Change in subsidy structure is forecast Many variables: level of water use Cost/type of primary heating Durability of solar system – long term Future energy costs At today’s prices solar can contribute approx Euro200 – 300 per annum. Hartwick Rule: Invest profits from natural resource use in technological replacements 26
Commercial Installations: Hotels/B&B’S – solar makes a lot of sense Old Rectory Kinsale:
Tesco – large daytime occupancy:
Further information: info@ecologics.ie www.ecologics.ie Thank You!