Il Hydronic Heat Pump Applications; Radiant Floor Heating; Fan Coils - Econar GeoSource 2000 GW Series Installation And Operating Instructions Manual

II.
HYDRONTC
HEAT
PUMP
APPLICATIONS
A. Radiant Floor Heating
Radiant floor
heat tubing
is
probably
the most popular
form of
hydronic heating.
It
provides excellent comfort
and
very high
efficiencies
by
supplying
Iow
temperature
fluid to
the
floor
slab and
keeping the
heat concentrated
evenly near
the floor.
Radiant
floor
systems
heat
the
occupants
and
surfaces
directly with
comfortable radiant
energy.
In
contrast, forced air heating moves
air
around
the building, which can
create temperature sffatification,
drafts, and air
rising to
the
ceiling.
Remember that hot air
rises,
radiant energy
does
not.
Radiant
floor
heating usually consists
of
1/2 inch plastic
tubing @EX)
approximately one linear
foot of pipe
per
square
foot of floor
space.
This value is
doubled
for
one
pass along the outside
walls to
concentrate
more
heat
in
that
area.
The tubing
is generally laid into
the
concrete
slab
floor
of
the building. New construction
techniques
have also made installation
into
wood floors
and
suspended
floors possible. The amount and spacing
of
the
tubing is
sized
to
meet the heating load
of
the
space
at
a
certain
fluid
temperature
in
the tubing.
To
optimize
efficiency and capacity, the
fluid
temperature
in
the
tubing should
be
maintained
as
low
as
comfortably
possible.
The type
of floor
covering and the spacing
of
the
pipe in
the floor
have
the
greatest effect
on
operating fluid
temperature.
Table
1
gives a rough
estimate
of
expected
operating temperatures
for
specific
floor
coverings:
Table
1-
Floor
ECONAR
designs
its hydronic
heat
pumps using
a
115oF
leaving water temperature
(L\W)
design
point.
This
LWT
is the ideal maximum fluid
temperature for radiant floor
systems.
Higher
operating temperatures
would
result
in
aa
uncomfortable
hot feeling
in
the conditioned
space.
In
fact, boilers
connected
to
radiant
floor
heating
systems
must be restricted
to a
115oF maximum
temperature
by
mixing
valves or other control
devices.
Suppliers
of
radiant floor
heat exchanger tubing can help
size the length
of pipe
and
fluid
temperature required
for
specific radiant
floor
heat exchanger applications.
Be
sure
to include two
inches
of polystyrene
insulation
under the
slab and two to four inches around the perimeter
down to
a
four-foot
depth.
This
insulation reduces the heat loss
to
the ground
and
decreases
the
response
time
of
the heating
system.
Insulation is
as
important
in
radiant
floor
heating
as
it
is
in
other methods
of
heating. Poorly insulated buildings
can
result in
higher
floor
temperatures
needed
to
heat
the
building, which
could
exceed the
level
of human comfort.
Night
setback controls are
not
recommended
on
radiant
floor
systems due to the slow
response
time of
the
slab,
and radiant
floor
systems
are not
usually recommended
for cooling,
since
poor dehumidification
and
cold/clammy
floors may result. To provide cooling to
a radiant floor
heating installation, the installation
of
an
ECONAR
FC
fan coil unit is
recommended.
Another
alternative
is
a
GeoSource
DualTEK
combination
heat
pump.
B. Fan Coils
Fan
coils,
such as
the ECONAR FC
series, can be
used
with
ECONAR's hydronic
heat pumps
in
the heating
and
cooling mode.
In
many
cases,
radiant
floor
heating
and
fan coil
cooling
are used together. Fan
coils also provide
dehumidification
in
the cooling
mode, and the rate
of
dehumidification
can
be
adjusted
by
selection
of
the
fan
coil
operating temperature.
Many different
sizes and configurations
of fan coils
are
available,
making
them
very flexible to
each
particular
application. Valence heating
and cooling systems, which
use
natural
convection
to
move
air.
can also tre
verv
versatile.
c"Important
-
Fan
coil
units
for
cooling must have
a
condensate
pan; and
if
accidental water
discharge could
cause
property
damage, there
must
also be a drained drain
pan under
the
unit.
Fan coils
are sized
for
capacity at specific
water
flow
rate
and
temperature combinations. Sizing
also
depends
on air
temperatures, air
flow
rates
(which
remain constant
based
on fan
speed selection and static pressure
differential),
and
humidity
conditions. The fan coils
are then
matched
to
the heat
pump at a
cofitmon
system
flow
rate
and
operating temperatue
to
provide
the overall
system
capacity to
a space
load.
High
static pressure fan coils
have
recently come onto
the
market, which
work well with
ECONAR's hydronic
heat
pumps. These
systems
provide
heating and cooling for
houses
without ductwork. They
use
a
high
static pressure
blower
to
supply
air
through small tubes, which
run
through
chaseways
to the
living
space. The blower
passes
air though
a
water-to-air coil
that
is
coupled
to
a
hydronic
heat
pump
to provide
heating and cooling. These
systems
work nicely
on
retrofit
applications
where ductwork isn't
available
or
wanted.
.,
100
Floor Coverins
Temn{T)
Cametins
115
Tile/Linol
eum/Hard
Wood
Concrete/Ouarrv
Tile
- Residential
85
Concrete/Ouarrv
Tile
- Commercial
70