File - Kensa Heat Pumps
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Transcript File - Kensa Heat Pumps
Kensa Heat Pumps
Follow on training
Agenda
Introduction
Heat Pump Operation
Application
Design/MCS/ Pricing
Ground Arrays – unrolling and purging
Simple diagnostics and fault finding
Q&A, product viewing
Lunch
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Heat Pump Cycle
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3
Heat Pump Performance
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The efficiency of a
heat pump is
mainly governed
by the outlet
temperature
4
Heat Pump Performance
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Inlet temperature also can have an affect on COP
5
Heat Pump Efficiency
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Real-life efficiency is expressed as a SPF (Seasonal Performance Factor) which is a very
complex calculation and is influenced by numerous factors quite distinct from the heat
pump performance.
Kensa’s heat pumps use Copeland scroll compressors, the most advanced available,
and capable of providing the best available performance.
Branding of the heat pump is not the critical factor in determining performance.
Factors linked to the property and the site are far more influential.
Ability to highlight the impact of some of these factors is helpful in gaining credibility
with the client.
6
6
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Domestic Heat Pumps
R407C
R134a
Size
Compressor
Size
Compressor
4kW
Single
3.5 kW
Single
6kW
Single
4.3kW
Single
8kW
Single
6kW
Single
10kW
Single
7kW
Single
12kW
Single
8.5kW
Single
12kW
Twin
10kW
Single
16kW
Twin
12kW
Twin
20kW
Twin
17kW
Twin
24kW
Twin
20kW
Twin
30kW
Twin
Single Compressor internals
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Twin Compressor Internals
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Hybrid Heat Pumps
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Single Phase Twin Compressor
R407C and R134a
15kW and 21kW
10
Shoebox Heat Pumps
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11
Plant Room Modules
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20 to 75 kW per module.
Combinations up to 1 MW and
beyond
15
Application
Application is critical
If a heat pump fails we can fix it, but if the application is wrong........
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Application - Exercise
Points to consider when installing a GSHP
i.e. Type of fuel replacing
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Application
How well insulated is the building?
What type of heating?
What fuel are we displacing?
Floor Construction.
Amount of glazing.
Noise issues.
Available heat source.
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Insulation
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The better you insulate your building : The lower the flow temperature required by the underfloor heating system to
reach your target temperature
Therefore, the less the heat pump has to raise the temperature
And the more efficient the heat pump!
The better you insulate your building, the more efficiently the heat
pump will operate.
19
The better insulated the building
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Smaller the heat pump required
The less the digging/drilling required
Lower the capital cost
Lower the building’s carbon emissions
Lower the energy bill
20
Heating Distribution Methods
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Underfloor
Ideal, large emitting area therefore low input temperatures.
Beware floor coverings and method of installation which might
require the heat pump to operate at higher temperatures.
21
Heating Distribution Methods
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Radiators
Need a higher temperature than underfloor due to the lower heat
emitting area.
Might need oversized radiators as maximum temperature from
the heat pump is approx. 50C.
22
Mixing radiators and underfloor
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Some want radiators upstairs, and underfloor downstairs
Can this be done?
Yes
Depending on the floor construction, the temperature required by the
radiators can be the same as the underfloor system!
There is a delay between the radiators and underfloor feeling warm.
Zone valves are generally required.
23
DHW Production
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25
Secondary Returns
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Standard secondary returns cause the cylinder
temperature to drop and due to the low
temperature nature of heat pumps this
temperature drop cannot be recovered
26
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DHW Cylinders
Single or Twin Coils
(Coil designed and sized for Heat Pump
applications)
3kW Immersion Heater
Expansion Vessel
G3 Kit
Stainless Steel tanks guaranteed for 25
years against leaks.
27
Inverted houses
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Bedrooms downstairs, living area upstairs.
Depends on floor construction.
Might need to run at higher temperatures and standard
rate electricity.
Glazing
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Beware high areas of glazing.
(even triple glazing only retains 1/3rd of the heat a solid wall does)
Will be cool in winter when cold ambient conditions.
Additional heating such as log burners.
Noise Issues
Keep the heat pump away from noise sensitive
areas.
Similar noise to an oil fired boiler or running
dishwasher.
Can install external to the building at the back of a
garage or in a lean to.
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Buffer Vessels
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Fitted to avoid short-cycling, i.e. which is where the heat
generated during the minimum run time for the heating
appliance (usually several minutes) cannot be absorbed
by the buildings distribution system.
Buffer Vessels
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2 connection buffer vessels are more
efficient
If close control of all
temperature zones is
not required then
‘open’ zones of the
underfloor can be
used as the buffer
vessel.
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Project Example – Sizing The Heat Pump
New Build Four Bedroom Detached Property with Garage
33
Sizing
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Internal area – Ground Floor & First Floor
Total Internal area = 224.6m2
Heat load =
224.6 x 40w/m
(If New Build)
= 8984
= 8.98 kW
34
Budget Pricing
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Budget Pricing
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SAP sizing – Line 37!
SAP Report - Line 37
Heat Loss Coefficient x Temperature Difference
-2°C (Min) to 21°C (Max) = 23°C rise
378.45 x 23 = 8704W = 10kW (39W/m)
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