Renewable Energy Open Day Scotland

ees-renewables.co.uk0800 294 4104

Thomas DicksonGlow Worm

Clearly Heat Pumps

Glow-worm’s NEW range of straightforward air to water heat pump system

4May 1, 2023

• Climate change

• Fuel Security • Fuel Poverty

Key drivers for recent legislation

changes and government incentives

• Carbon Usage

• Legislation

• Building Regs

5May 1, 2023

Why select an air to water heat pump system?

Oil and LPG price volatility is leading to an increase in interest in cost effective alternatives particularly in off gas locations

Eliminates need for on-site fuel storage, e.g. LPG, oil or biomass

Can be used as part of an efficient all-electric heating solution

Excellent payback period compared to alternatives such as standard electric, LPG or oil

Reduces reliance on imported gas and oil supplies

Less external work (and cost) compared to GSHP

Paying for heating is becoming more painful, investing in a heat pump now can save more in the

future.

6May 1, 2023

•E

vaporator •

Con

dens

er

• Compressor

• Expansion device

•The compressor draws in the refrigerant gas and circulates it at high pressure once more round the system

• This plate to plate heat exchanger transfer the

heat from the refrigerant into

the heating circuit

•As the refrigerant passes through the expansion valve it expands and draws heat from it’s surroundings

•The sub-cooler absorbs heat from the liquid flow to improve efficiency

•The refrigerant absorbs the heat as it changes from a liquid to a gas

•The sub-cooler ensures than any liquid refrigerant is boiled off before it returns to the compressor

•Example of a working refrigeration cycle

•14 bar, 67 ºC

•14 bar, 34ºC

•4 bar, 6,5 °C

•4 bar, -3ºC

• 14

bar,

25ºC

•4 bar, 2,5ºC

7May 1, 2023

Air to Water Heat Pumps – How do they work?

Heat pump efficiency

In the example above the COP = 4/1 = 4 (i.e. 400% efficient) so you get 4kW of heat for 1 kW of electrical power consumed

‘Free’ heat from external air

Electrical powerHeat into heating

system

Heat pump efficiency is stated as the Coefficient of Performance (COP)

Heat output (kW)COP = ------------------------------- Power consumed (kW)

8May 1, 2023

Air to Water Heat Pumps – How do they work?

Low Temperature Heat emitters & DHW

Heat emitter selection and heat pump flow temperature have a big effect on AWHP performance. Higher temperatures = Lower efficiencies

• The Heater Emitter Guide for Domestic Heat pumps covers the topic of which emitters to select and how that selection will affect the overall efficiency. • A good rule to follow is – The lower the flow temperature the more efficient the heat pump. (approx 35ºC flow temperature is ideal)• Low temperature radiators or UFH make this possible for heating applications• For DHW however higher temperatures are required; selecting the right fit for purpose cylinder is a must to ensure a highly efficient system.• AWHPs use an electric immersion heater to supplement the charging of the DHW; The Glow-worm system makes sure the heat pump gives as much heat as possible before bringing in the immersion - giving greater efficiencies. • DHW generation therefore is not the most efficient use of a heat pump, particularly when gas supplies are available

9May 1, 2023

Sizing a heat pump is a complete system sizing, emitters should be size correctly for the lower temperature flow that a heat pump provides

Envirosorb3 output table

•When sizing a heat pump system in the UK the heat pump must be able to do 100% of the heating 99% of the time with out the need of a back heater.

• Heating system are generally sized at -3°C although this does change around the UK according to MCS

•Ensure that the output can meet the heating demand of the property at -3°C is a very good rule of thumb before a full heat loss calculation is carried out

• Any heat pump system using a flow rate over 50°C cannot get RHI due to the MCS star rating system for emitters •The lower the flow rate of the heat pump the better the all round performance, the better the performance the more RHI the end user can receive

10May 1, 2023

Air to Water Heat Pumps – How do they work?

• Maximum heating output for domestic applications is 15kW ( 230V) at A7/W35

• Maximum output temperature is 63°C

• Efficiency decreases with higher output temperatures and lower ambient temperatures, care must be taken when applying an AWHP to DHW or high temp radiator system

• When installed as primary heat source, you need to correctly size radiators and/or specify UFH

• When selecting a heat pump, you are really selecting a HEATING SYSTEM that includes a heat pump as such a complete system design approach should be used.

• To get the best out of your heat pump you want it to run for long periods of time at low temperatures

• Your radiators / emitters will not get “hot” but will get warm you may need to point this out to the homeowner

Specifying a heating system – Air to water heat pumps Other Considerations

11May 1, 2023

Direct heat pump system – Cost Focused

Feature Benefit Heat pump connects directly to the heating system

Easy to install

Entire system is filled with Glycol Heat pump and system protected down to -15°C

Most simple heat pump installation Quick installation time

Full system controlled centrally (via Systempro) Quick and simple wiring and easy to use

12May 1, 2023

Direct heat pump system with back up heater

Feature Benefit Heat pump connects directly to the heating system

Easy to install

Entire system is filled with Glycol Heat pump and system protected down to -15°C

Wall hung 6kW in-line back up heater Gives the heating system a boost in extreme weather conditions (outside the design)

Full system controlled centrally (via Systempro) Quick and simple wiring and easy to use

13May 1, 2023

Direct heat pump system with buffer

Feature Benefit Heat pump connects directly to the heating system

Easy to install

Entire system is filled with Glycol Heat pump and system protected down to -15°C

Wall hung buffer tank Acts a low loss header as well and ensuring a body of heat is available as multiple zones open and close

Full system controlled centrally (via Systempro) Quick and simple wiring and easy to use

14May 1, 2023

Direct heat pump system with Hex module

Feature Benefit Heat pump connects directly to the heating system

Easy to install

Only the heat pump to hex module is filled with glycol

Less glycol in the system gives a lower cost and less maintenance over time

Wall hung Hex module Includes fill and flush points and ErP ready CH pump.

Full system controlled centrally (via Systempro) Quick and simple wiring and easy to use

15May 1, 2023

Hybrid option

16May 1, 2023

System schematics

• NB : Domestic Hot water production taken care of by system boiler + storage / combination boiler

•Example Heating schematic

17May 1, 2023

• Heat pump cylinders are design to match the requirements and performance of heat pumps.

• The coil sizes within a heat pump cylinder are larger to increase heat transfer from the lower flow temperatures.

• Typically heat pumps only produce flow temperatures of 55°C instead of 80°C as produced by a gas boiler.

• Glow-worm heat pumps can produce a flow temperature reaching 63°C making heat up times even better.

• Typical heat up are as quick as 39 mins even at 55°C flow temperature. (more data follows)

What's the benefit of a heat pump cylinder?

Current cylinders not providing efficient solution for heat pump installations

*25 years guarantee for shell with all other parts covered by 2 years parts and labour

18May 1, 2023

Sustain Boiler Range Overview

Type Outputs kW Size

Combi 25,30, 35 700 x 390mm

System 12, 15, 18, 25, 30 700 x 390mm

Regular 12, 15, 18, 25, 30, 35 600 x 375mm

Key Features

Rear flue option and cupboard fit dimensions

Remote diagnostic options

Low maintenance Aluminium Heat Exchanger

Grundfos High Efficiency pump

ERP Ready A rated boilers

Club Energy Alliance – warranties, servicing, GSR and Benchmark

19May 1, 2023

•Develop concepts to increase competitive ability of Sustain boiler

Established market leading competitor products

Product Characteristics Database (PCDB)

Category = boiler, mains gas, combi

Ecoblue combi

24, 28, 33

Logic combi

24, 30, 35

Flexicom combi

35

SAP annual efficiency [%,Hs] 89.0 89.0 89.1

SAPwinter seasonal Efficiency [%,Hs] 89.9 89.9 90.0

SAPsummer efficiency [%,Hs] 87.3 87.3 79.9

Comparative hot water efficiency [%,Hs] 77.6 71.0 62.4

SEDBUK

Sustain boiler UK25, 30, 35

89.3*

90.3*

87.3*

78.0*

+0.4%

+0.5%

+0.5%

+12.2%

TaskforceENOStargets

ENOS Taskforce Background

*Subject to change (to be revised upwardly)

20May 1, 2023

Thank you for your attention.

Renewable Energy Specialistsees-renewables.co.uk0800 294 4104