DT117/4 Sustainable Build & Design - Class Presentations

1. Presented by Sean Keegan
Suitable Build & Design
Lecturer Sonya Daly
GSHP Sustainable Build & Design Sean Keegan

2.  GSHP uses Geothermal Energy from heat
exerted by the earths core
 The ground maintains stable temperature
between 11-13oC
 Energy can be recovered from the ground,
water or air but GSHP’s utilizes the stable
ground temperature as its source of energy
 Substitute for conventional heating systems
 Can be a considered zero-carbon source of
energy
GSHP Sustainable Build & Design Sean Keegan

3.  Horizontal Collector system:
 laid in trenches 0.5-1.8m
 Vertical Collector system:
 laid in bores 100-
150mm diameter &
20-150m deep
 Direct expansion heat
transfer- open loop
 Indirect expansion heat
transfer- closed loop
GSHP Sustainable Build & Design Sean Keegan

4.  System consists of a ‘ground loop’ pipe
 Filled with a mixture of water and antifreeze (Glycol)
buried in a trench or borehole
 Electric pump powered by electricity/solar /wind
source circulates mixture in loop.
 ‘Pump up’ collected heat at low temperature and
release it at a higher temperature.
 Transfers the heat collected to a hot water tank.
 Heat is then used to supply under floor heating or
radiators.
 Indirect system uses secondary pipe work and closed
loop.
 Direct expansion heat transfer- open loop, more
efficient but environmental issues and more system
design needed because of inflexible copper work.
GSHP- Sean Keegan

5.  Radiators, underfloor heating and hot water supply.
 Recommended for newly constructed houses with
adequate insulation and air-tightness that meet the
latest building regulations.
 Suited to homes with under-floor heating.
 Not generally suitable for properties with existing
gas-fired central heating systems.
 Temperature delivered between 45-55oC for
general use and 30-45oC for under floor heating.
 Hot water in cylinder will be pumped up by an
emersion to meet require temperature.
 Can be incorporated in concrete piles.
GSHP Sustainable Build & Design Sean Keegan

6. GSHP Sustainable Build & Design Sean Keegan
 Materials
◦ Indirect Collector: highly-density
polyethylene pipe; flexible closed
loop
◦ Direct expansion: copper pipe; direct
installation
 Methods
◦ Horizontal: trenches 0.5-1.8m deep,
excavated by a digger
◦ Vertical: bore holes 20-150m deep,
excavated by a drilling rig

7.  Efficient performance needs good thermal contact
with the ground- so ensure adequate backfill
 Supplys30-50% of hot water demands- topped up
electrical supply
 Insulation costs vary depending on ground condition
and choice of vertical or horizontal vertical
€10,000-12,000
 Payback 8-10 years, with a 20 year life expectancy
 Every unit of electricity used by the pump, you get
between 3-4 units of heat
 You still need to use electricity to drive the pump, so
a ground-source heat pump can’t be considered
completely zero-carbon unless this is provided by a
renewable source, such as solar power or a wind
turbine.
GSHP- Sean Keegan

8. GSHP Sustainable Build & Design Sean Keegan
 15- 50% less than traditional electrical heating or oil
heating costs
 No extra maintenance needed same as typical annual
boiler services
 Low noise & good visual aesthetics; only pump visible but
usually in garage
 cheaper off peak rates can be used to maintain heat within
cylinder
 Can provide a well disturbed central heating system
 Lower carbon emissions
 Well suited for underfloor heating

9.  Initial insulation costs are high
 Groundworks required to dig the trench &
bore holes can be expensive and disruptive
 Horizontal installation can be restricted by
the size of the building plot
 Not suitable for properties with existing gas-
fired wet central heating as the technology
works at lower temperatures, making it better
suited to homes with under floor heating.
GSHP Sustainable Build & Design Sean Keegan

10. The Sustainable Energy
Authority Ireland operate a
Greener Homes Scheme that
provide grants to individuals
who wish to make there
homes more environmentally
friend
23% of applications are for
GSHP
The average successful
grant received is €2000
GSHP Sustainable Build & Design Sean Keegan

11.  GSHP’s provide an environmentally friendly
heating source
 Initial high investment with reduced utilities
bills
 Suitable for new well insulated homes
GSHP Sustainable Build & Design Sean Keegan

12.  Sustainable Energy Authority Ireland website
www.seai.ie
 ‘Ground Source Heat Pumps’ Home Heating
Systems www.which.co.uk
 ‘Assessment of Hybrid Geothermal Heat Pump
Systems ‘(2001), Federal Energy Management
Program, U.S. Department of Energy
 ‘Ground Source Heat Pumps: A Technology
Review’ (1999) by R. Rawling & J Sykulski,
Department of Electrical Engineering, University
of Southampton
GSHP Sustainable Build & Design Sean Keegan