An Introduction to Heat Pumps
Dispelling the myths about Air and Ground Source heat pumps
1
Presentation Overview Introduction to Heat Pumps •
Market drivers and the “Carbon Challenge”
Chris Davis Head of Renewables, Dimplex UK
Overview of Heat Pump technology •
Operational principles and types of heat pump
Factors affecting efficiency •
What is CoP? Heating system types and hot water
Dale Banks Training Manager, Dimplex UK
Using the air as a heat source •
Sizing, selection and system design principles
Using the ground as a heat source •
Sizing and selection, ground collectors types and dimensioning
Frequently asked questions Dimplex Accredited Installer Scheme
Chris Davis Head of Renewables, Dimplex UK
Chris Booker
Wolesely SBC Open forum – questions/ view products
Product Development Manager, Wolseley Sustainable Building Center
Presentation Overview Introduction to Heat Pumps •
Market drivers and the “Carbon Challenge”
Allen Griffiths Business Development Mgr, Dimplex UK
Overview of Heat Pump technology •
Operational principles and types of heat pump
Factors affecting efficiency •
What is CoP? Heating system types and hot water
Dale Banks Training Manager, Dimplex UK
Using the air as a heat source •
Sizing, selection and system design principles
Using the ground as a heat source •
Sizing and selection, ground collectors types and dimensioning
Frequently asked questions Dimplex Accredited Installer Scheme
Allen Griffiths Business Development Mgr, Dimplex UK
Chris Booker
Wolesely SBC Open forum – questions/ view products
Product Development Manager, Wolseley Sustainable Building Center
Dimplex Heat Pumps
UK market leader in electric heating, based in Southampton More than 25 years experience in the manufacture of heat pumps Manufacturing plant based in Kulmbach, Germany Historically servicing German, Swiss, Austrian and French markets Produce over 30,000 heat pumps a year Product ranges include: • Ground source • Air to water • Water to water
Market Drivers Political • •
Climate change Security of supply
Legislative • • •
Building Regulations Part L Scottish Technical Standard J PPS22
Social • •
Escalating fuel costs Fuel poverty
Policy • • •
Code for Sustainable Homes Zero Carbon Homes Microgeneration Strategy
Incentives •
Grant funding schemes
Improving Building Efficiency 50% of UK carbon emissions come from buildings Around 60% from heating and hot water Legislation in the form of Building Regulations Part L • Conservation of fuel and power • Maximum CO2 targets for new buildings • “Zero carbon” new homes by 2016
UK Carbon dioxide emissions
Code for Sustainable Homes Designed as “a single national standard to be used in the design and construction of new homes” Measures overall building sustainability across 9 performance categories • Including a number of mandatory standards
6 star rating scheme Performance standards in excess of minimum Building Regulations • Indicates direction and likely performance levels for future regulations
Code for Sustainable Homes: Energy Compliance Targets PART L 2010
PART L 2013
PART L 2016
PART L: CO2
Low Carbon Technology
Code Level 1 10% Code Level 2 Code Level 3
Code Level 4
Code Level 5
Code Level 6
Energy Efficiency
14% 25%
“Renewables” 44%
100%
>100%
The Importance of Space & Water Heating 50% of carbon dioxide emissions from buildings Heating and hot water major energy consumers CO2 emissions breakdown: Part L compliant building (gas heated)
Source: Energy Savings Trust
Heat Pumps
Highly energy efficient solution for space and domestic water heating •
Alternative to a central heating boiler
Able to convert solar energy stored in the ground, air or underground water into usable energy for heating and hot water
Energy sourced from environment is • • •
Totally free Inexhaustible Always available
Low carbon emissions •
30 – 50% lower than gas systems
Low running costs
Proven, reliable & low maintenance
Where The Energy Comes From
Lower Carbon Emissions
Heating Type
Typical Efficiency
Typical CO2 emissions per kWh (kg)
CO2 emissions per kWh delivered (kg)*
CO2 emissions for 15,000kWh/yr (kg)
Condensing Gas Boiler (A rated) Gas Boiler Existing
90%
0.19
0.21
3150
80%
0.19
0.24
3600
Condensing Oil Boiler
90%
0.25
0.28
4200
Existing Oil Boiler
80%
0.25
0.31
4650
Electric storage heating
100%
0.43
0.43
6450
Heat pump (worst case scenario)
250% (CoP 2.5)
0.43
0.17
2550
Heat pump (good scenario)
300% (CoP 3.0)
0.43
0.14
2100
Heat pump (better scenario)
350% (CoP 3.5)
0.43
0.12
1800
Heat pump (best case scenario)
400% (CoP 4.0)
0.43
0.11
1650
Lower Running Costs
Heating Type
Typical Efficiency
Typical Fuel Unit Cost (p/kWh)
Cost per kWh delivered (p)**
Running cost for 15,000kWh/yr (£)
Condensing Gas Boiler (A Existing rated) Gas Boiler
90%
3.06
3.40
£510.00
80%
3.06
3.82
£573.00
Condensing Oil Boiler
90%
5.8 (60p/litre)
6.44
£966.00
Existing Oil Boiler
80%
5.8 (60p/litre)
7.25
£1087.00
Electric storage heating
100%
5.37
5.37
£805.50
Heat pump (worst case scenario)
250% (CoP 2.5)
8.16*
3.26
£489.00
Heat pump (good scenario)
300% (CoP 3.0)
8.16*
2.72
£408.00
Heat pump (better scenario)
350% (CoP 3.5)
8.16*
2.33
£349.50
Heat pump (best case scenario
400% (CoP 4.0)
8.16*
2.04
£306.00
Overview of heat pump technology
Dale Banks
Heat Pumps
Highly energy efficient solution for space and domestic water heating •
Alternative to a central heating boiler
Able to convert solar energy stored in the ground, air or underground water into usable energy for heating and hot water
Energy Sourced from environment is • • •
Totally free Inexhaustible Always available
Low carbon emissions, low running costs
Proven, reliable & low maintenance
How a Heat Pump Works Heat Source
Heat Pump
Heat Distribution
Compression
Evaporator Condenser
Expansion
1. 2. 3. 4. 5.
Large quantity of low grade heat is absorbed from the environment. Changes refrigerant from a liquid to a gas (in the Evaporator) Refrigerant gas is compressed (using an electrically driven compressor), raising its pressure and temperature Heat exchanger (Condenser) then extracts the heat from the hot gas and transfers it into heating systems water Refrigerant liquid passes through an expansion valve, reducing its pressure and temperature Refrigerant enters the evaporator where large quantity of low grade heat is absorbed from the environment. Changes refrigerant from a liquid to a gas.
How Does a Heat Pump Work? ¾ environmental energy + ¼ electrical energy 1kW electrical energy in 3-4kW heating energy out 300-400% efficiency
Section 1.1 How a Heat Pump Works
17
How a heat pump works Like a refrigerator / freezer
Evaporator / Heat Exchanger
A fridge takes heat from the food and air inside and passes it to a evaporator at the back of the unit Uses the same refrigeration cycle as a heat pump A heat pump removes heat from heat source and moves it to the heating system inside homes and businesses Condenser / Heat Exchanger
Section 1.1 How a Heat Pump Works
18
How a Heat Pump Works Closed Loop Refrigeration Cycle
Consists of 4 Main Components
Section 1.1 How a Heat Pump Works
Refrigerant / Working Fluid 19
Changing State of Refrigerant, Fluid and Gas Change of State in Fluids: 1
2
3
4
5
5 3
1.
Liquid
2.
Liquid Heating Up
3.
Changing State at Constant Temperature & Pressure 1. 2.
4
Boiling or Evaporation Liquid & Gas Mixture
2 1
Temperature
4.
Gas Only
5.
Gas Heating Up / Superheat
20
Effect of Pressure on Boiling Points 3.0 2.5 2.0
Pressure / Bars
1.5
Atmospheric Pressure
1.0 0.5 0.0
0 -75
20 -70
40 -65
60 -60
80 -55
100 -50
120
Temperature °C
21
Water Refrigerant
Heat Pump Anatomy Electrical connections and controller High pressure switch Compressor Condenser Filter/dryer Sight gauge
Evaporator Ground source heat exchanger Low pressure switch Expansion valve
Refrigerant Cycle A
B
D C
A – Low Pressure COOL Refrigerant GAS B – High Pressure HOT Refrigerant GAS
C – High Pressure COOL Refrigerant LIQUID D – Low Pressure COLD Refrigerant LIQUID
..\REFRIGERATION ANIMATION.exe
23
Environmentally Friendly Refrigerants Refrigerant R407C/R404A • HFC (Hydro Fluro Carbon) refrigerants currently acceptable for use in today’s environment • Low Global Warming Potential (GWP) • Zero Ozone Depleting Potential (ODP) • Long term use for manufacturing until 2020 • The refrigeration system is a pre-charged, self contained circuit. • It requires no additional work during installation • There is no need for installers to have refrigerant handling registration
Section 1.1 How a Heat Pump Works
24
Types Of Heat Pump Systems
25
Ground Source Heat Pumps
Extract solar energy stored in the ground
Collectors buried in the ground
•
Flexible PE pipe
•
Horizontal or vertical
Water/glycol mix circulated through collectors to transfer heat from ground
Ground Source Heat Pumps - The Heat Source Approximately 1000kWhrs/m2 of heat energy strikes the ground annually in the UK The Earth acts a solar battery storing the suns energy The ground and water absorbs the suns energy and retains this energy as heat Ground Heat Sink in Summer Ground Heat Source in Winter
Section 1.3 Types of Heat Pump
27
Ground Collectors
Air Source Heat Pumps
Use latent heat in the ambient air as the heat source Can be installed indoors or outdoors
Operational down to -20°C
Variability in temperature affects CoP and output throughout the year
Good CoP’s achieved in UK due to relatively high ambient winter air temperatures •
circa 4°C
Air Source Heat Pumps – Heat Source Energy from the air at low temperatures Absolute zero = -273°C = 0 K (Kelvin) At -273°C no more energy can be taken out from the environment.
-273° Section 1.3 Types of Heat Pump
-30° Air Is Full Of Energy
0° +30°
30
Typical Applications
31
Refurbishment Project – Luxury Barn Conversion Luxury barn conversion, Northamptonshire 11kW Dimplex ground source heat pump Borehole collectors Underfloor heating and domestic hot water LCBP grant funded
Contemporary New Build Luxury new build home, NW England 22kW high temperature Dimplex air source heat pumps Bivalent system •
Working in conjunction with a gas boiler
Underfloor heating, domestic hot water and swimming pool Dimplex Accredited Heat Pump Installer
Meadow Well Community Centre 50kW Dimplex gshp system Providing heating via underfloor Horizontal ground collectors 50% grant funding under Low Carbon Buildings Programme Phase 2 Installed in conjunction with rain water harvesting, solar thermal and wind turbines Dimplex “Non Domestic Installation of the Year”
Schools
Achieving a lot of success in the schools sector Mainly LCBP Phase 2 funded
Grange Primary School (bottom pic) • • • • • •
Installed by Earth Energy Ealing Borough Council 40kW high temperature ground source 15 boreholes Meets 10% renewables “Merton” target Success followed by 2 further installations for 24kW and 37kW gshp’s respectively
Social Housing
Housing Associations s are a major area of opportunity
Fall within scope of LCBP Phase 2 grants and CERT funding
A few projects of note: • • •
Growing interest for large quantities of off-gas homes •
Cornwall Rural HA – 9 gshp’s at Goonhilly Close Flagship HA – 5 gshp’s Moray Housing Partnership – 2 ashp’s
Oil, Electricity or Solid Fuel heated
Blocks of flats treated with a “communal” hp system
Importance Of Matching Heat Pump To Building Load
37
Building Types Not all buildings are suitable for a heat pump! •
Buildings should be: – –
•
Heat pumps are designed to be energy efficient – – –
•
Well insulated Old, “leaky” buildings with solid walls can be a problem
Run at low temperatures Energy wastage needs to be reduced by insulation Best suited to new / well insulated buildings
Existing buildings – – –
Ensure energy efficiency is considered first! Insulation, double glazing, etc Energy Savings Trust
Fundamentals Carry out a comprehensive assessment of the building Take account of all key factors: • • • • •
Location Design temperature Wall, floor and roof insulation levels Windows and doors Air changes
Section 2.1 Calculating heat losses
39
Heat Loss Calculation Vital that an accurate heat loss calculation is carried out Don’t rely on rules of thumb! • OK for rough quotation / budget purposes • Not good enough for system design
Use a recognised, accurate software package For new build, the building designer will have calculated the heat loss SAP (Standard Assessment Procedure) Report should be available on all new builds Rd SAP (Reduced Data) on existing properties For LARGE projects, Dimplex will calculate building heat losses
Section 2.1 Calculating heat losses
40
Matching the Heat Pump to the Building IT IS ESSENTIAL THAT THE HEAT PUMP IS SIZED TO SUIT THE BUILDING LOAD. • Over sizing the Heat Pump • causes the unit to cycle on and off more frequently – reduces the heat pump efficiency – reduces compressor life cycle
• Under sizing the Heat Pump • means inadequate heating is provided • the unit will be unable to satisfy the load and will require supplementary heating so running costs will be high • defrosts will be more frequent.
Section 2.1 Design Fundamentals
41
Balancing Act ELECTRICITY (25%)
RENEWABLE ENERGY (75%)
IMPORTANT that Building heat load (kW) • •
Space heating Water heating
Is MATCHED By Heat pump size (kW) AND Heat source capacity (kW) • •
Renewable energy Electricity
HEAT ENERGY REQUIRED (100%)
Under Sizing
Under sizing the heat pump tips the balance •
Heat pump not sufficient to meet the heat load of the building
Difference has to be made up with the use of supplementary electric heating
Under Sizing ELECTRICITY (50%)
RENEWABLE ENERGY (50%)
Under sizing the heat pump tips the balance •
Heat pump not sufficient to meet the heat load of the building
Difference has to be made up with the use of supplementary electric heating (or other heat source)
• Installation Costs reduced • Running Costs increased
FACTORS AFFECTING HEAT PUMP PERFORMANCE
Coefficient of Performance, the “CoP”
46
Coefficient of Performance, the CoP Expression of heat pump efficiency Indication of the electrical energy used and heat delivered
75% heat energy from the environment
25% electrical energy
=100% heating energy Example 4kWh of heat output from Heat Pump using only 1kWh of electrical energy = CoP 4 47
Coefficient of Performance CoP affected by: • Heat source temperature / Air / Ground / Water – Higher Source Temperature / Higher efficiencies – Lower Source Temperature / Lower efficiencies
• Heating system water flow temperature – 35ºC Lower Flow / Higher efficiencies – 50ºC Higher Flow / Lower efficiencies
• Additional supplementary heating / immersion / boiler
CoP continually varies • A spot measure of performance at optimal conditions – A7/W35 – B0/W35
• Much like car mpg figures 48
System Design
49
System Alternatives Mono Valent Operation
Heat pump covers 100% of the annual heating/hot water requirements No supplementary heat sources required
1 4
Typical ground source installation
3 2
1. Heat pump 2. Buffer tank 3. DHW cylinder 4. Brine pump/connections
Section 1.4 Applications
System Alternatives Mono Energy Operation
Heat pump covers a proportion of the annual heating / hot water requirements 1
Supplementary heat source, electrical immersion cover remaining load Common to Air Source installation
2 4
3 5
1. Heat pump 2. Buffer tank 3. DHW cylinder 4. Brine pump/connections 5. Immersion Heaters
Section 1.4 Applications
System Alternatives Bi Valent Operation
Two heat generators • •
Heat pump Gas/oil boiler/solar thermal
Heat pump covers the heating requirements to determined temperature (bivalent point)
Backed up by secondary heat source in parallel
Most often used in retro fit situations
Allows smaller heat pumps to be used to minimise installation costs
1 5 2 4 1. Heat pump 2. Buffer tank 3. DHW cylinder 4. Brine pump/connections 5. Gas/oil boiler
Section 2.3 System Alternatives
3
Heating Distribution System
53
Space and Water Heating Heat pumps can provide both space heating and domestic hot water • 35-55ºC water temperature
Underfloor heating
Underfloor heating is ideal • • •
Lower temperatures required Larger surface area, typically 35 – 40ºC Helps heat pump run more efficiently – SAP benefit
•
Screed can act as thermal store
Space and Water Heating Heat pumps can provide both space heating and domestic hot water • 35-55ºC water temperature
Radiators
Higher flow temperatures required Compromises heat pump efficiency •
SAP correction factor
Require larger surface area than for conventional boilers
Space and Water Heating Heat pumps can provide both space heating and domestic hot water • 35-55ºC water temperature
Other alternatives
Fan convectors
Perimeter radiators
Lower water temperatures required
Helps heat pump run more efficiently •
SAP benefit
Space and Water Heating Heat pumps can provide both space heating and domestic hot water • 35-55ºC water temperature
Domestic Hot Water
Important to use correctly sized cylinder Heat pump will run at lower CoP •
SAP adjustment
Immersion boost required to achieve storage temperatures over 50ºC “High temperature” heat pumps now becoming available •
Improve SAP performance for DHW
Domestic Hot Water Cylinders DHW Cylinders Fully UK approved for G3 Building Regulations Factory fitted T&P valve Safety kit supplied, comprising: • 2.5kW immersion • Pressure reducing valves (x2) • Tundish (x2) • Twin t’stat and cut outs • Differential pressure valve • 2 port motorised valve • Expansion vessel
Section 2.5 Dimplex ASHP Range
58
USING THE AIR AS A HEAT SOURCE
Tapping the heat source Outdoor installation
Heat source easy to tap Weatherproof heat pump installed on a sturdy concrete base Water pipes and electric cables are securely laid under the ground
Indoor installation
Outside air is tapped via air ducts between the heat pump and external walls Heat pump is installed against an external wall Insulated opening is protected by a rain guard
Outdoor and Indoor Heat Pumps Dimplex LA MS and LA AS ranges
For outdoor installation Variable flow temperatures up to 55ºC 11kW and 16kW single phase 20kW – 40kW twin compressor, three phase High temperature versions available Extremely quiet due to insulation and fan design High CoP’s across a range of air temperatures Operate at outdoor temperatures as low as -20ºC
Indoor installation
8kW, single phase “integrated” heat pump Fits neatly into the corner of a room (utility, garage) Simple “plug and play” installation, with built in • • • •
50l buffer tank 2kW immersion heater Circulation pumps Safety group
Performance Information
Full technical details on every heat pump
Performance / output curves at various air and water flow temperatures
Air Source Heat Pump Sizing Sized according to system design •
Monovalent / Monoenergy / Bivalent
Heat pump sized in line with accurate heat loss calculations and domestic hot water requirements. Flow temperature of heating system will affect heat pump output and selection. • Under floor heating @ 35ºC • Radiators @ 50ºC
Output reduces with falling ambient temperature and the heat pump requires selecting to operate at the desired • •
Design Temperatue Bivalent Point!
Section 2.2 Heat pump selection
63
Balance Point – Bivalent Point HP OUTPUT kW
18.8 16 11 kW 19 14 17 kW
1ºC Ambient 10ºC 20ºC 15ºC 5ºC 21ºC
HEATING LOAD kW
10 0 8 kW 0.5 11 4
Balance Point – Bivalent Point HP OUTPUT kW
11 kW
HEATING LOAD kW
1ºC Ambient -1ºC BALANCE POINT or BIVALENT POINT
11 kW
Below Bivalent Point - 1ºC HP OUTPUT kW
10.5 kW
Supplementary Heating Switches On
HEATING LOAD kW
-1ºC Ambient
11.5 kW
Balance Maintained Using Secondary Heat Source HP OUTPUT kW
11.5 kW
-1ºC Ambient -3ºC
HEATING LOAD kW
11.5 kW
Design Temperature HEATING LOAD kW
HP OUTPUT kW
10 kW
-3ºC Ambient
Additional Supplementary Heating Switches Required
12 kW
Balance Maintained Using Additional Heat Source HP OUTPUT kW
12 kW
-3ºC Ambient
HEATING LOAD kW
12 kW
Balance Point – Bivalent Point HEAT PUMP OUTPUT FALL AS BUILDING LOAD INCREASES
Balance Point 1.5ºC & 12.2kW Design Temperature -3ºC
kW
Heat Pump Output @-3ºC Building Load @ -3ºC Amount Of Supplementary Heating Required
Ambient Temp
www.dimplex.co.uk Online Planning Tools HP Hydraulic Integration Tool HP Step By Step Design Guide PDF Hydraulic Layout Diagram Installation Legend
Buffer Tanks
72
Buffer Tanks pg45PPIM What is a buffer tank? • A thermal store, sized at least 10% of minimum heating water volume flow rate required through the heat pump. • Note: Every hydraulic design must ensure that the heating water flow rate of the heat pump is met.
• i.e. LA 11MS = 1.0m³/h (1000l/h) therefore buffer volume to be 100l
Why fit one? • A buffer tank is absolutely essential for air to water heat pumps to: – To allow the defrost cycle to happen – To allow supplementary heating – To improve the economy and efficiency of the system
Section 2.4 Heat distribution systems
73
Buffer Tanks pg181PPIM PSP 140E built under buffer tank for compact heat pumps Heating Circuit Water
Flow From HP
NOTE - No internal coil / heat exchanger
PSW 200 ltr separate buffer
74
What Can Happen If The Defrost Cycle Doesn’t Run
75
Optimising Dimplex Heat Pumps Series connection, flow
9
• Highest possible heating circuit temperature • Accurate return flow sensor • Provides the most efficient system
Parallel connection
8
• Short circuit of heated water within the buffer • Lower flow temperature to heating circuit
Series connection, return flow
8 Section 2.3 Heat distribution systems
• Will cause false readings in return flow sensor • Will cause delay in heat pump response
76
USING THE GROUND AS A HEAT SOURCE
Ground Loop Heat Source Extract solar energy stored in the ground • 0.0001W from earths core
Collectors pipes are buried in the ground •
Consisting of flexible PE pipe
A water / glycol mix is circulated through these pipes to absorb heat from ground • Referred to as the Brine solution • Mixture of fresh water and antifreeze to provide protection down to -20°C
Section 1.3 Types of Heat Pump
78
Ground Source Heat Pumps During the summer energy is stored in the ground and water course / Charging the earth •
Heat Sink
During the winter the stored energy can be removed by the heat pump / Discharging •
Heat Store
Section 1.3 Types of Heat Pump
79
The ground as a heat source
Ground type dictates the rate at which heat transfers between the warmer ground and cooler brine circuit
The ground can only give up a certain amount of energy and varies with the geology conditions
The amount of heat energy required is dependant on the heat pumps capacity and total annual energy required.
The rate of heat transfer per linear meter dictates the length of collector pipe required and land area needed
80
Geological conditions Typical abstraction rates for horizontal and slinky heat exchangers
Soil Types
Abstraction Capacity 1800 hrs/annum
Abstraction Capacity 2400 hrs/annum
Sandy soil ( dry )
q = 0.010 kW/m
q = 0.008 kW/m
Loamy soil ( dry )
q = 0.020 kW/m
q = 0.016 kW/m
Loamy soil ( wet )
q = 0.030 kW/m
q = 0.025 kW/m
Loamy soil (saturated)
q = 0.040 kW/m
q = 0.032 kW/m
Section 1.3 Types of Heat Pump
81
IT IS ESSENTIAL THAT THE HEAT PUMP AND GROUND COLLECTOR ARE SIZED TO SUIT THE BUILDING LOAD.
Section 2.1 Design Fundamentals
82
Under sizing The Collector Less solar irradiance strike the earth in Winter than in Summer Under sizing the collector can result in to much energy being removed from the ground The ground may not recharge fully from season to season The collector can cause the ground to cool, eventually freeze and cause the heat pump to fail Inadequate heating of the property will occur and supplementary heating may be required CoP falls Section 1.3 Types of Heat Pump
83
Over Sizing The Collector Increased cost More collector pipe than required • Increased pressure drop
Large pump may be required • Higher running cost • Higher electrical consumption
Large site excavation to accommodate unnecessary pipe
Section 1.3 Types of Heat Pump
84
Horizontal Ground Collectors
Ground collectors can be laid horizontally
Normally 32mm dia PE pipe
Depth 1.2 – 1.5m
Spacing 0.75m apart
Lower cost than boreholes
Requires large land area
Lower heat extraction rates 10 – 35W/m (depending on ground type)
Vertical Slinky Collectors Ground collectors are laid vertically in coils Normally 32mm dia PE pipe Depth 1.2 – 1.8m Trench widths Approx 300mm Spacing between trenches of 5m Low cost of installation Requires less excavation work Low heat extraction rates
86
Vertical Ground Collector
Boreholes can be used when space is confined or large capacity is required
Efficiency benefit •
Lower temperature fluctuation
Boreholes typically 65 – 100m deep
32mm or 40mm dia pipes
Boreholes typically 200mm dia
Single or double u-probe configuration
High heat extraction rate •
35 – 100W/m (depending on ground type)
Ground Source Heat Pumps Typical abstraction rates for bore hole heat exchangers for • •
1800 hr annual running time 2,400 hr annual running time
Section 1.3 Types of Heat Pump
DOUBLE U VDI GUIDE
88
Frequently Asked Questions
Chris Davis Allen Griffiths
89
How much will a heat pump cost? What are the running costs? What’s the payback?
Costs
You get what you pay for!
Don’t be short changed…
Balancing Act ELECTRICITY (25%)
RENEWABLE ENERGY (75%)
IMPORTANT that Building heat load (kW) • •
Space heating Water heating
Is MATCHED By Heat pump size (kW) AND Heat source capacity (kW) • •
Renewable energy Electricity
Under Sizing
Under sizing the heat pump tips the balance •
Heat pump not sufficient to meet the heat load of the building
Difference has to be made up with the use of supplementary electric heating
Under Sizing ELECTRICITY (50%)
RENEWABLE ENERGY (50%)
Under sizing the heat pump tips the balance •
Heat pump not sufficient to meet the heat load of the building
Difference has to be made up with the use of supplementary electric heating (or other heat source)
• Installation Costs reduced • Running Costs increased
Air Source Heat Pumps ASHP output and CoP reduce with air temperature LA 11 MS air source heat pump at A-7 / W35 CoP = 2.9
Capacity = 7.6kW
at A2 / W35 CoP = 3.4
Capacity = 9.1kW
at A7 / W35 CoP = 4.1
Capacity = 10.9kW
at A10 / W35 CoP = 4.6 Capacity = 12.0kW
Installation Costs: Domestic Systems
Estimated installation prices for new build home, 11kW heat pump for heating and hot water
Ground Source Heat Pump Horizontal
Ground Source Heat Pump Borehole
Air Source Heat Pump
SI 11 ME
SI 11 ME
LA 11 MS
Heat pump cost
£3500
£3500
£5600
Ancillary items (hot water cylinder, buffer tank, manifolds, etc)
£2600
£2600
£2050
Ground collector and installation (including ground works)
£2000
£8000
-
Heat pump installation and commissioning
£2500
£2500
£1400
£10,600
£16,600
£9,050
Dimplex heat pump (11kW)
Total (excluding grants)
(2 boreholes)
Running Costs Will be dependent on a number of factors: – Heating system type (ufh, radiators) – Electricity tariffs you use
Savings relative to the fuel being replaced – Oil, electricity, LPG and gas have different costs
Good savings to be made against oil, LPG and electricity – Low natural gas prices – Low heat loss new build
Running Costs – New build home
Running costs – Refurbished home
Payback Not simply a question of fuel costs! Need to consider also: • Not just a comparison of boiler cost – Cost of bringing gas on site or – Cost of oil/lpg tank, bund, etc
• Cost of annual maintenance – Gas/oil boilers require regular maintenance for safety purposes
• Lifetime of the system and cost of replacement – Modern condensing boilers last less than 10 years – Heat pump will last for 20 – 25 years (we can prove it!) – Ground collectors (50% of the cost) will last for over 50 years
Annual Ownership Costs
Integrating with other renewables
Heat Pump and Solar Hot Water Dimplex heat pump optimised hot water cylinder Dimplex “SST25” solar pump station • Solar and hot water circuits separated by plate heat exchanger
Solar has priority over heat pump for provision of hot water Heat pump remains available for space heating
Solar providing hot water and space heating support Solar panels feed into a “thermal store” Domestic hot water provided “instantaneously” Thermal storage provides buffering for space heating system Mixer module controls heating circuit temperatures
Grants and Financial Incentives
Grants Whole of the UK: • Low Carbon Buildings Programme (Householder) • Ground source heat pumps – 30% up to a maximum of £1200 against the product/installation costs
• Air source heat pumps – 30% up to a maximum of £900 against the product/installation costs – Available mid 2008
Scotland • Scottish Community & Householder Renewables Initiative • 30% up to a maximum of £4000 • Includes ground source and air source VAT levied at only 5%
Is this going to be a big market?
Heat Pump CO2 Reduction Potential Renewable Energy & CO2 Reduction vs Mains Gas (SPF=3)
90%
90%
80%
80%
70%
70%
60%
60%
50%
50%
40%
40%
30%
30%
20%
20%
10%
10%
% CO2 reduction
100%
100%
0%
0% 0%
20%
40%
60%
80%
100%
Fractional size of heat pump Renewable heat
CO2 Reduction
© Earth Energy Ltd
Existing homes Increasing fuel prices Home Information Packs / Energy Performance Certificates Off gas areas Replace or work in parallel with existing boiler systems CERT funding – social housing sector
Example shows existing home, heated with radiators, heating and DHW
UK Domestic Heat Pump Market – The Future? 50,000 heat pumps per year is probably a conservative estimate
UK He at Pump M arket - 2004 - 2020 60000
50000
It represents:
40000
30000
20% of the new build housing market •
20000
10000
(250,000 / year)
3% of total annual heating installations •
(1.5m per year)
0 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
2007: Circa 3700 units
2010 & 2013: Step change in Building Regulations
2016: All new homes “Zero Carbon”
1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007
5000
10000
6100
15000
12960
20000
Oil prices
• Poor installations caused heat pump sales to fall, despite increasing oil prices 18217
21900
25000
8330 5240 3550 2440 1520 1000 700 550 420 850 1000 1270 1400 1800 2300 3578 4367 4719 5736 8215 8326 9745 12639
560
Heat pump installations 45000
35000
30000 40
0 30
20
10
0
Oil Price E100L
50000
43886
Heat Pump Market in Germany 70
60
40000
50
Importance of good design A heat pump is only as efficient as the system it is installed into… System design affects performance and efficiency • Heating system • Domestic hot water • Hydraulic design
Ground collector sizing and hydraulics • Ground heat extraction rates vary with ground/collector type • Hydraulic layout and pumping loads
Reliance on supplementary heating • Correct sizing of the heat pump for the heat load of the building
Microgeneration Certification Scheme (MCS)
Intended to provide a robust certification scheme for microgeneration products and installers
Voluntary scheme
Managed by BRE Accreditation
Underpins the Low Carbon Buildings Programme • •
Grants only available to certified installers for certified products Migration of products/installers from ClearSkies
Installer scheme requirements •
Demonstrate sufficient competence, experience and training – Dimplex training
• •
Robust quality system Sign up to the REAL Code of Conduct (Renewable Energy Assoc)
“Self funding” scheme
www.greenbooklive.com
Dimplex Accredited Installer Scheme
Dimplex “Accredited Installer” scheme • • • •
Air source heat pumps •
Air source heat pumps Ground source heat pumps Aligned with requirements of MCS Independent certification by Logic
2 day training course
Ground source heat pumps •
3 day training course
Redeemable vouchers to offset training costs
Access to Dimplex commissioning and extended warranty
Pre and Post installation technical support from Dimplex
Marketing benefits
Supported by Wolseley Group
Summary Requirement for low carbon buildings is here and now Renewable heat has a major part to play in delivery Heat pumps without doubt are going to be an important growth sector for the domestic heating sector Heating installers and contractors need to have an awareness of the right application opportunities A sound understanding of the technology crucial to delivering good quality installations and real carbon savings – training! Market drivers and products are available – the challenge is to the heating and plumbing sector to evolve to meet the demand gap
Thank you for your attention. Questions? www.dimplex.co.uk
