Note: Descriptions are shown in the official language in which they were submitted.
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AIR CONDITIONING/DEHUMIDIFYING UNIT
TECHNICAL FIELD
[1000] This invention is directed toward an air
conditioning/dehumidifying unit and
a method of operating the unit. The invention is more particularly directed
toward an air
conditioning/dehumidifying/pool water heating unit for use with indoor
swimming pools
and to a method for operating the unit.
BACKGROUND ART
[1001] Air conditioning/dehumidifying units normally have air
passageway means
with a main passageway and air inlets and outlets associated with the main
passageway.
The units have refrigeration means with an evaporator, followed by a first
condenser, in
the main passageway and a second condenser outside the main passageway and
usually
outside the building housing the main passageway. Fan means are provided to
draw the
air to be conditioned/dehumidified through the passageway including through
the
evaporator and the first condenser in the passageway. The first condenser in
the
passageway is used to reject heat during dehumidification. The second
condenser
outside the passageway is used to reject heat during air conditioning.
[1002] Having the second condenser outside the passageway, and
usually outside
the building housing the passageway, on most air conditioning/dehumidifying
units,
particularly those used for indoor swimming pools, has a number of
disadvantages. The
location of the second condenser, separated as it is from the remainder of the
unit,
requires a relatively large amount of refrigerant for proper operation of the
unit. The
large amount of refrigerant required is quite expensive and to replace any
leakage is also
expensive. The use of a large amount of refrigerant also requires the use of
refrigerant
oil adding to the cost. The use of a large amount of refrigerant further
requires many
controls, including costly control valves, to protect the compressor from
liquid flood back.
The installation of the control valves, involving brazed joints, is costly.
Servicing and/or
replacement of the valves is also costly. Also, the shipping and installation
of the second
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condenser is relatively complicated and expensive. Installation requires
construction of a
separate pad for the second condenser; a separate electrical service; the
installation of
associated refrigerant piping at the site to connect the condenser to the rest
of the unit;
the loading of the refrigerant charge into the unit at the site; and the
necessary testing
required on-site once the unit is installed to ensure that it operates
correctly in all modes
of operation. In addition, the location of the second condenser outside the
building may
detract from the appearance of the building.
[1003] It is known to have air conditioning/dehumidifying units for
indoor
swimming pools that heat the pool water. The units have a refrigerant/pool
water heat
exchanger. Older units used a simple water valve to control the flow of water
through
the heat exchanger as needed. Hot refrigerant gas was continually passed
through the
heat exchanger to heat the pool water. When heating of the pool water was not
required, the hot gases passing through the heat exchanger caused
mineralization of
standing pool water in the heat exchanger. As a result, deposits built up in
the heat
exchanger and slowed the flow of water through it. Cleaning/replacement of the
heat
exchanger was expensive. Newer units now usually employ at least one diverter
valve to
divert hot refrigerant gas to the heat exchanger to heat the pool water as
required.
Diverter valves are however expensive to use and to replace since refrigerant
must be
removed from, and then added to, the refrigerant system during replacement.
BRIEF DESCRIPTION OF THE INVENTION
[1004] It is one purpose of the present invention to provide an air
conditioning
/dehumidifying unit which unit is much easier and cheaper to build, install,
operate, and
service than known units. It is also the purpose of the present invention to
provide a unit
which is more versatile and efficient in operation than known units. It is
another purpose
of the present invention to provide an air conditioning/dehumidifying unit for
indoor
swimming pools which can be easily modified to simply and effectively heat
pool water
when required. It is a further purpose to the present invention to provide
methods of
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simply and easily conditioning and treating air in enclosed spaces, and
particularly in
indoor swimming pools, and for heating swimming pool water when needed.
[1005] In accordance with the present invention there is
provided an air
conditioning/dehumidifying unit having novel air passageway means allowing use
of a
single condenser rather than two condensers. The unit is compact and thus
requires a
much smaller charge of refrigerant resulting in significant cost savings and,
even more
likely, in the use of alternative, more costly, environmental-friendly
refrigerants. The unit
is substantially completely assembled and tested at the place of manufacture
and not at
the installation site. No separate installation of a second condenser at the
site is required.
No mounting pad for a second condenser is needed and no installation of
refrigerant
lines or a separate electrical service is needed at the site. The unit is
fully charged with
refrigerant at the factory and not at the site thereby minimizing the
possibility of
refrigerant contamination or compressor damage while charging in the field.
The unit can
be fully tested at the factory rather than waiting for some of the testing to
be completed
at the site. The unit, being compact, is easily shipped and installed.
Shipping costs are
reduced since there is no separate, second condenser to ship.
[1006] The air conditioning/dehumidifying unit of the present
invention can be
readily operated in an air-conditioning mode, a dehumidifying mode; and a
purge/ventilating mode. The unit, when used in an indoor swimming pool, can be
modified to have a pool water heater and can be further operated in a pool
water
heating mode; an air-conditioning/pool water heating mode; and a
dehumidifying/pool
water heating mode. The unit can simply and easily modulate the head pressure
of the
refrigerant during operation thereby providing better efficiencies in the
operation; better
control of the properties of the air within the indoor area and better control
of the
heating of the pool water if a pool water heater is employed. The unit can
also provide
for lower static pressure during operation resulting in reduced operating
costs.
[1007] The air conditioning/dehumidifying unit of the present
invention employs air
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passageway means comprising two adjacent passageways for air passing through
the
unit. The second passageway normally is substantially larger in cross-
sectional area than
the first passageway. The first passageway has a first indoor air inlet and a
first outdoor
air inlet at one end and an indoor air supply outlet at the other end. An
indoor air supply
blower is located in the first passageway near the indoor air supply outlet.
The second
passageway has a second indoor air inlet and a second outdoor air inlet at the
end and
an outdoor air outlet at the other end. An outdoor air blower is located in
the second
passageway near the outdoor air outlet.
[1008] The unit has a refrigerant system which has a
compressor, a single
condenser, an expansion valve, and an evaporator, all the elements connected
in series
in a closed loop by refrigerant piping as is well known. The evaporator is
located in the
first passageway near the one end and the condenser is located in the second
passageway about midway between the ends of the passageway. The unit has a
damper
associated with each of the four air inlets and a damper assembly downstream
from the
evaporator located in the first passageway and between the first and second
passageways. The air from the evaporator can normally flow directly through
the first
passageway and out of the indoor air supply outlet. However the damper
assembly can
be used to selectively divert some or all of the air from the evaporator
through the
condenser in the second air passageway before leaving the indoor air supply
outlet. The
position of the air inlet dampers and of the dampers in the damper assembly
for
controlling the flow of air through the two passageways, along with the
operation of the
two blowers and the compressor in the refrigerant system, will depend on the
mode of
operation of the unit.
[1009] The installed unit can be operated as a dehumidifier for
dehumidifying the
air in an indoor area. In this mode of operation, with the indoor air supply
blower and
compressor operative and the outdoor air blower inoperative, air from the
indoor area is
passed into the first passageway from the first indoor air inlet and through
the
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evaporator to remove moisture from it. The other three air inlets are closed.
At least part
of the air from the evaporator can be diverted by the damper assembly to the
condenser
in the second passageway to heat it, and then returned to the first passageway
to mix
with the remainder of the air from the evaporator before being returned to the
indoor
area. The damper assembly modulates the air flow over the condenser to control
the
head pressure of the refrigerant.
[1010] The unit can be operated as an air conditioner for
conditioning the air in
the indoor area. In this mode of operation, with both the blowers and the
compressor
operative, the indoor air is passed through the first passageway from the
first indoor air
inlet, through the evaporator to remove moisture from it, and returned
directly to the
. indoor area via the indoor air outlet. Simultaneously, outside air is
passed through the
second passageway from the second outside air inlet, through the condenser to
remove
heat from the condenser, and back outside through the outdoor air outlet. The
first
outdoor air and the second indoor air inlets are closed.
[1011] The unit can also be used to purge or ventilate the indoor
area. In this
mode of operation, both blowers are operative but the compressor is normally
inoperative. Air from the indoor area is exhausted by the outside air blower
drawing the
air into the second passageway from the second indoor air inlet, through the
condenser,
and to the outside through the outdoor air outlet. At the same time,
replacement outside
air is drawn into the indoor area through the first outdoor air inlet, the
first air
passageway, through the evaporator and through the indoor air outlet. The
first indoor
air and second outdoor air inlets are closed.
[1012] If the replacement air being brought in during purging is hot
and humid,
the compressor can be operated and the air brought in through the first
outdoor air inlet
in the first passageway is passed through the evaporator and cooled before
entering the
indoor area. The air being simultaneously exhausted from the indoor area
through the
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second passageway passes through the condenser to remove the heat taken out of
the
air by the evaporator. If the air being added is cold, the compressor can be
operated and
at least some of the air from the evaporator can be routed through the
condenser in the
second passageway using the damper assembly to heat it before entering the
indoor
area. In this operation, the replacement air would be added alternatively with
the
removal of the indoor air. Alternatively, without using the compressor, a
supplemental
heater can be provided in the first passageway to heat the cold air.
[1013] The construction of the unit, in having the evaporator in
a first passageway
and the condenser in a second adjacent passageway, separate from the first
passageway, provides for more efficient operation of the unit. The second
passageway
can be substantially larger in cross-sectional area than the first passageway
and thus the
face area of the condenser can be increased compared to the face area of the
evaporator
to increase the efficiency of the unit. During dehumidifying, the air passing
through the
condenser can have a larger area to pass through, reducing static pressure and
thus
reducing the power required to move the air. During air conditioning, the
outside air
passing through the second passageway and the condenser is at a lower static
pressure
since the air does not pass through the evaporator, which can be clogged with
water
droplets, and since the size of the condenser is increased. In addition, the
static pressure
in the first passageway is lowered when at least some of the air passes out
through the
passageway from the evaporator to the indoor area without having to pass
through the
condenser during dehumidifying and when all of the air from the evaporator
avoids the
condenser during air conditioning. As a result of reducing static pressure,
overall power
consumption is reduced.
[1014] The air conditioning/dehumidifying unit, when used in an
indoor swimming
pool, can have a pool water heat exchanger for heating pool water. With a pool
water
heat exchanger, the unit can be used to heat pool water, to dehumidify and
heat pool
water simultaneously, or to air condition and heat pool water simultaneously.
Refrigerant
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from the condenser is passed directly through the heat exchanger to heat the
water.
The heating of the pool water is fully modulated by controlling the flow of
water through
the pool water heat exchanger. If the temperature of the water drops below a
set point,
the flow of pool water is started through the heat exchanger, via a pump in
the water
system, by opening a water valve. The flow can be increased by further opening
of the
valve if required. The temperature of the refrigerant passing through the heat
exchanger
is controlled by controlling its head pressure. The head pressure is
controlled by
modulating the flow of air over the condenser through the damper assembly. If
the air
flow is reduced, the head pressure is increased, increasing the temperature of
the
refrigerant. If the air flow is increased, the head pressure is reduced,
reducing the
temperature of the refrigerant. Refrigerant normally enters the pool water
heat
exchanger as a hot gas to heat the water and as a hot or warm liquid when
little or no
heating is required. If there is no pool water flowing through the heat
exchanger, the
head pressure is decreased to have refrigerant flow as a warm liquid through
the heat
exchanger so as to avoid overheating the stagnant water in the heat exchanger.
[1015] The unit provides simple control of the head pressure of
the refrigerant
without requiring the use of expensive regulating valves. During most modes of
operation of the unit, the temperature of the refrigerant, either after
leaving the
condenser, or after leaving the pool water heat exchanger, can be sensed by a
temperature sensor to give an indication of the head pressure. If the
temperature sensed
is low, the temperature sensor can control the damper assembly or the outside
air blower
to allow less air flow through the condenser thus increasing the head
pressure. If the
temperature sensed is high, the damper assembly, during dehumidifying,
dehumidifying/pool water heating or pool water heating modes, can be modulated
to
allow more air to flow through the condenser thus lowering the head pressure.
During air
conditioning and air conditioning/pool water heating modes, the outside air
blower speed
can be modulated to control the flow of outside air through the condenser to
control
head pressure.
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[1016] The invention is particularly directed toward an air conditioning
/dehumidifying unit with a first air passageway and a second air passageway
adjacent to
the first air passageway. Dampered inlets at one end of the passageways
selectively
provide indoor air or outdoor air to each passageway. The first passageway has
an
indoor air outlet and the second passageway has an outdoor air outlet, both
outlets at
the other end of the passageways. A first blower is provided in the first
passageway and
a second blower is provided in the second passageway for moving air through
each
passageway. A refrigerant system is provided on the unit with an evaporator in
the first
passageway, a compressor, a condenser in the second passageway and a
refrigerant line
joining the evaporator, the compressor and the condenser, in series, in a
closed loop.
The unit has a damper assembly for selectively directing at least some air
from the
evaporator in the first passageway through the condenser in the second
passageway, if
desired, before passing it out the indoor air outlet in the first passageway.
[1017] The unit can have a pool water heat exchanger for heating pool
water. The
refrigerant line in the refrigerant system then leads from the condenser to
the heat
exchanger and from the heat exchanger to the evaporator. There are no valves
in the
refrigerant line section leading from the condenser to the heat exchanger. A
refrigerant
condition sensor in the line, near but downstream of the heat exchanger,
controls the
damper assembly to control the head pressure of the refrigerant.
DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[1018] Fig. 1 is a schematic elevation view of the air
conditioning/dehumidifying
unit;
[1019] Fig. 2 is a schematic elevation view of the unit in a
dehumidifying mode of
operation;
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[1020] Fig. 3 is a schematic elevation view of the unit in an
air conditioning mode
of operation;
[1021] Fig. 4 is a schematic elevation view of the unit in a
purge/ventilating mode
of operation; and
[1022] Fig. 5 is a schematic elevation view of the unit with a
pool water heating
system.
DETAILED DESCRIPTION OF THE INVENTION
[1023] The air conditioning/dehumidifying unit 1, shown in Fig.
1, has a first,
preferably straight, air passageway 3 and a second, preferably straight, air
passageway 4
extending through the unit between the ends 5, 6 of the unit. The second air
passageway 4 is preferably adjacent and parallel to the first air passageway 3
and they
preferably share a common wall 7. The first air passageway 3 has a first
indoor air inlet 8
and a first outdoor air inlet 9 at one end 11 of the passageway. The first air
inlets 8, 9
extend through one end 5 of the unit. The first indoor air inlet 8 is
connected to an
indoor air return duct 13 on site to bring air from an indoor area to the
first air
passageway 3. The first outdoor air inlet 9 is connected to an outdoor air
duct 15 to
bring air, from outside an enclosure enclosing the indoor area and the unit,
to the first air
passageway 3. The first air passageway 3 also has an indoor air outlet 17 at
the other
end 19 of the passageway. The indoor air outlet 17 extends through the other
end 6 of
the unit and connects to an indoor air supply duct 21 for returning air to the
indoor area.
[1024] The second air passageway 4 has a second indoor air
inlet 25 and a second
outdoor air inlet 27 at one end 29 of the passageway. The second air inlets
25, 29 also
extend through the one end 5 of the unit. The second indoor air inlet 25 is
connected to
a second indoor air return duct 31 that brings air from the indoor area to the
second air
passageway 4. The second outdoor air inlet 27 is connected to a second outdoor
air duct
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33 to bring air from outside the enclosure to the passageway 4. The second air
passageway 4 also has an outdoor air outlet 35 at the other end 37 of the
passageway.
The outdoor air outlet 35 extends through at the other end 6 of the unit and
connects to
an outdoor air return duct 39 for returning air from the passageway 4 to the
outside.
[1025] While the indoor air inlets, outdoor air inlets, indoor
air outlet and outdoor
air outlet have been shown as being located in the ends 5, 6 of the unit 1, it
is to be
understood that they can also all be located in one of the sides 40 of the
unit with the
indoor air inlets 8, 25 and outdoor air inlets 9, 27 located adjacent the end
5 of the unit
and the outlets 17, 35 located adjacent the other end 6 of the unit. Air
inlets 8, 9 are still
at the end 11 of the passageway 3 and indoor air outlet 17 is still at the
other end 19 of
passageway 3. Similarly, air inlets 25, 27 are still at the end 29 of
passageway 4 and the
outdoor air outlet is still at the other end 37 of passageway 4. Having the
inlets and
outlets in one side of the unit allows the unit to be mounted in an interior
corner of the
enclosure.
[1026] Dampers are provided on all four air inlets 7, 9, 25 and
27. The damper 43
on the first indoor air inlet 8 is normally closed. The damper 45 on the first
outdoor air
inlet 9 is also normally closed. The damper 47 on the second indoor air inlet
25 is
normally open. The damper 49 on the second outdor air inlet 27 is normally
closed. The
dampers 43, 45, and 49 that are normally closed can be selectively powered
open and
the damper 47 that is normally open can be selectively powered closed. A
damper
assembly 51 is also provided in both air passageways 3, 4 about midway between
the
ends 5, 6 of the unit for selectively moving air from the first air passageway
3 to the
second air passageway 4 and then back to first air passageway 3. The damper
assembly
51 has a first assembly damper 53 in the first air passageway 3 about midway
between
the ends 11, 19 of the first air passageway 3 that is normally open, opening a
through
port 55 in a cross-wall 56 in the first passageway. The damper assembly 51
includes a
second assembly damper 57 in front of the first assembly damper 53 and
normally
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closing a first bypass port 59 in the common wall 7 connecting the first
passageway 3 to
the second passageway 4, and a third assembly damper 61 behind the first
assembly
damper 53 and normally closing a second bypass port 63 in the common wall 7
connecting the second passageway 4 to the first passageway 3. The assembly
dampers
53, 57 and 61 in the damper assembly 51 are operated in unison by a single
operator
through suitable known linkages (not shown). The dampers 53, 571 61 in the
damper
assembly 51 in their normal flow-through position, as described, allow air to
flow directly
through the first passageway 3 from one end to the other. When the position of
the
dampers is reversed to a by-pass position (i.e. the open damper 53 is closed
and the
closed dampers 57, 61 are opened) air flows from the first passageway 3 to the
second
passageway 4 through first by-pass port 59 and then back to the first
passageway 3
through the second by-pass port 63. The damper assembly 51 can be used to
modulate
the air flow from the first passageway 3 to the second passageway 4 and back
to the
first passageway 3 by partly closing the damper 53 in the first passageway 3
and partly
opening the dampers 57, 61 in the bypass ports 59, 63. An indoor air blower 65
is
provided in the first passageway 3 near its other end 19 and an outdoor air
blower 67 is
provided in the second passageway 4 near its other end 37.
[1027] The unit has a self-contained refrigerant system with an
evaporator 71 in
the first passageway 3 near the one end 11 of the passageway to intercept air
passing
through the passageway 3. The evaporator 71 is located in front of the damper
assembly
51. The refrigerant system has a condenser 73 in the second passageway 4 about
midway between its ends 29, 37, and between the first and second by-pass ports
59, 63
to intercept air passing through the second passageway 4. The refrigerant
system also
has a compressor 75 and an expansion valve 77 carried by the unit 1 outside
the first
and second passageways 3, 4. The compressor 75, the condenser 73, the
expansion
valve 77 and the evaporator 71 are connected in series in a closed loop by
suitable
refrigerant piping 79 as is well known.
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[1028] The cross-sectional areas of the first and second air passageways
3, 4 will
depend on the size of the coils in the evaporator 71 and condenser 73
respectively, as
selected for a particular application. The second air passageway 4 generally
will be
substantially larger in cross-sectional area than the first passageway 3. The
cross-
sectional area of the second passageway 4 can be up to one hundred and thirty
percent
larger than the cross-sectional area of the first passageway 3. Preferably,
the cross-
sectional area of the second passageway 4 is between fifty and one hundred
percent
larger than the cross-sectional area of the first passageway 3. The larger
cross-sectional
area of the second passageway 4 allows the condenser 73 in the second
passageway to
have a larger surface area than the surface area of the evaporator 71 in the
first
passageway 3. The larger surface area for the condenser 73 is particularly
useful in the
air-conditioning mode to be able to remove the heat given up by the air in
passing
through the condenser 73 efficiently.
[1029] When the unit 1 is used in a dehumidifying mode, as shown in Fig.
2, the
compressor 75 is turned on as is the indoor air blower 65 in the first
passageway 3. The
outdoor air blower 67 is off. The damper 47 on the second indoor air inlet 25
is powered
closed. The damper 49 on the second outdoor air inlet 27 is closed. The damper
43 on
the first indoor air inlet 8 is powered open and the damper 45 on the first
outdoor air
inlet 9 is normally closed. The assembly dampers in the damper assembly 51 are
in a by-
pass position with assembly damper 53 partly closing the first passageway 3
and
assembly dampers 57, 61 opened to partly open the first and second by-pass
ports 59,
63. With the unit 1 set up as described above, air from the indoor area is
drawn into the
first passageway 3 of the unit 1 by the indoor air blower 65 through the first
indoor air
return inlet 8. The air passes through the evaporator 71 where it is cooled to
remove
moisture and then some of the air passes through the opened first bypass port
57 into
the second passageway 4. In the second passageway 4, the air passes through
the
condenser 73 to heat it, through the second bypass port 59 back into the first
passageway 3 to combine with the remaining air from the evaporator, and back
to the
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indoor area through the indoor air outlet 17. The amount of air flowing over
the
condenser 73 is modulated by the damper assembly 51 to control both the amount
of
heat given to the air and the head pressure of the refrigerant.
[1030]
When the unit 1 is used in an air conditioning mode, as shown in Fig. 3, the
compressor 75 is turned on as are both the indoor air blower 65 and the
outdoor air
blower 67. The damper 49 on the second outdoor air inlet 27 is powered open.
The
damper 47 on the second indoor air inlet 25 is powered closed. The damper 45
on the
first outdoor air inlet 9 is normally closed. The damper 43 on the first
indoor air inlet 8 is
powered open. The damper assembly 51 is in the flow-through position with the
assembly damper 53 opened to open port 55 and thus the first passageway 3 and
the
assembly dampers 57, 61 closed to close the by-pass ports 59, 63. With the
unit set up
as described, return air from the indoor area is drawn into the first
passageway 3 of the
unit by the indoor air blower 65 through the first indoor air inlet 8. The air
passes
through the evaporator 71 where moisture is removed from the air, and then
continues
through the passageway 3 and back to the indoor area through the indoor air
return
outlet 17. Outside air is simultaneously drawn into the second passageway 4 by
the
outdoor air blower 67 through the second outdoor air inlet 27, passing through
the
condenser 73 to take heat from the condenser, and then out the outlet 35 to
the outside.
In having the indoor air pass only through the first passageway 3 and the
evaporator 71,
and not pass through an inactive reheat condenser as in prior art systems, the
system
has reduced static pressure and thus requires less power. With the passageway
4 larger
in cross-sectional area than the first passageway 3, the condenser 73 can have
a larger
surface area thereby reducing static pressure as the outside air flows through
the
condenser 73 and requiring less power to operate the unit. The outside air
flowing
through the condenser 73 can be modulated by the changing the speed of the
outside air
blower 67 to control both the amount of heat removed from the condenser 73 and
the
head pressure of the refrigerant.
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[1031] The unit 1 can be used to completely purge the indoor area or to
ventilate
it. If the indoor area is an indoor pool area, the pool area can be purged to
get rid of
contaminants in the pool area such as chlora mines, regardless of other pool
area air
conditions such as its humidity. The indoor area can be ventilated when
outside air
conditions are suitable for conditioning the air in the indoor area without
having to use
the compressor. Ventilating can occur, for example, when cooling of the indoor
area is
required and the outside air is cool enough to do this. When the unit 1 is
used in a
purge/ventilating mode, as shown in Fig. 4, the compressor 75 is normally
turned off and
both the indoor air blower 65 and the outdoor air blower 67 are turned on. The
damper
49 on the second outdoor air inlet 27 is closed. The damper 47 on the second
indoor air
inlet 25 is open. The damper 45 on the first outdoor air inlet 9 is powered
open. The
damper 43 on the first pool air inlet 8 is closed. The damper assembly 51 is
in the flow-
through position with damper 53 open and dampers 57, 61 closed. With the unit
set up
as described, outside air is drawn into and through the first passageway 3 by
the indoor
air blower 65 via inlet 9 and into the indoor area through indoor air outlet
17, while air
from the indoor area is drawn through the second passageway 4 by the outdoor
air
blower 67 via inlet 25 and outlet 35 to the outside. An air temperature sensor
80 can be
provided in the first passageway 3 to sense the temperature of the outside air
passing
into the indoor area. The sensor 80 is connnected to a controller 81, and if
the
temperature sensed is too cool, a heater 83 in the first passageway 3 can be
turned on
by the controller 81 to heat the air entering the indoor area. If the outside
air is quite
humid the compressor 75 could be turned on to have the evaporator 71 take
moisture
out of the outside air going into the indoor area. The indoor air going out in
passageway
4 would take heat away from the condenser 73. The purge/ventilation mode can
be
turned on manually or by a timer. The heater 83 could also be used to
supplementally
heat the air returning to the pool in the dehumidifying mode.
[1032] During the dehumidifying mode the head pressure of the refrigerant
can be
maintained at the required operating level by modulating the air flow over the
condenser
73. A refrigerant condition sensor such as a temperature sensor 85 senses the
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CA 02782287 2012-07-06
15.
temperature of the liquid refrigerant in the section of refrigerant line 79
leaving the
condenser 73 and passing to the expansion valve 77 via a receiver 89. The
sensor 85 is
connected to the controller 81. If the temperature of the liquid refrigerant
drops below a
predetermined set point, the controller 81 modulates the air flow over the
condenser 73
by partly closing the damper assembly 51 to reduce the air flow over the
condenser 73
and thus increase the head pressure. The damper assembly 51 can be opened more
if
the temperature of the refrigerant rises above a predetermined set point thus
increasing
the air flow over the condenser and lowering the head pressure. The head
pressure can
be controlled by a pressure transducer (not shown) instead of a temperature
sensor if
desired. The transducer is connected to the refrigerant line 79 to measure the
vapour
pressure of the refrigerant and to use the measure of this condition of the
refrigerant to
control the damper assembly 51 through the controller 81.
[1033]
During the air conditioning mode, the head pressure of the refrigerant can
be controlled by controlling the speed of the blower 67 in the second
passageway 4 so as
to control the amount of air passing over the condenser 73 in the passageway.
The
blower speed can be controlled, via the controller 81, by the refrigerant
temperature
sensor 85 that senses the temperature of the refrigerant or by a pressure
transducer.
[1034]
The unit 1, if used in an indoor swimming pool area, can include pool water
heating means. As shown in Fig. 5, the pool water heating means 91 can
comprise a
heat exchanger 93 inserted into the refrigerant line 79 just after it leaves
the condenser
73. There is no valve in the section 95 of line 79 between the condenser 73
and the heat
exchanger 93. Pool water from the pool is passed to, and returned from, the
heat
exchanger 93 via a line 97. A pool water temperature sensor (not shown) senses
the
temperature of the water and, through controller 81, controls a water valve
101 in the
water line 97 allowing the pool water to flow through the heat exchanger 93 so
as to be
heated by the refrigerant passing through the heat exchanger. A pump (not
shown)
pumps the water through the heat exchanger. When the pool water temperature is
at a
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CA 02782287 2012-07-06
16.
set point, the valve 101 is closed, and the refrigerant from the condenser
passing
through the heat exchanger 93 is a warm liquid. The refrigerant normally is
not warm
enough to foul any standing water in the heat exchanger. If the pool water
temperature
sensor senses a slight drop of the water temperature below the set point, the
valve 101
is slightly opened to start a flow of water through the heat exchanger 93 to
be heated by
the refrigerant. If the temperature continues to drop the flow of water is
increased by
further opening of the valve 101. As more heating is required, the refrigerant
temperature drops and the head pressure is reduced. This is sensed by the
refrigerant
temperature sensor 85 and the air passing over the condenser 73 is accordingly
reduced
by adjusting the damper assembly 51, or the speed of the outside air blower
67,
depending on the mode of operation of the unit, to allow the refrigerant head
pressure to
rise and the refrigerant to heat up to a hot gas to continue heating the
water. As the
water temperature approaches the set point, the water flow is reduced by the
valve 101
and the damper assembly 51 adjusts to allow more air to flow over the
condenser. The
water flow can be continually modulated so that the water temperature never
strays far
from the set point.
[1035] The unit can be operated in a dehumidifying/pool water heating
mode. The
dehumidifying operation is the same as described above in paragraph [1029] for
an
indoor environment except that the refrigerant is being passed through the
heat
exchanger on emerging from the condenser. While dehumidifying of the air is
occurring,
the pool water may require heating. If it does and the head pressure drops,
the damper
assembly 51 will adjust to pass less air over condenser 73 and thus raise the
head
pressure and increase the refrigerant temperature to continue heating the
water. As this
happens the dehumidifying process continues.
[1036] The unit can also be operating in an air conditioning/water
heating mode.
The air conditioning mode is the same as described above in paragraph [1030]
except
that refrigerant is being passed through the heat exchanger on emerging from
the
condenser. While air conditioning is occurring, the pool water may require
heating. If
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CA 02782287 2012-07-06
, .
17.
it does and the head pressure starts to drop, the outdoor air blower will slow
down to
pass less air past the condenser 73 and thus raise the head pressure and the
temperature of the refrigerant to continue heating the water to the set point.
As this
happens the air conditioning process continues.
[1037] If desired, the unit can be modified to include a water
cooled condenser for
use in place of the air cooled condenser 73 used for heat rejection. In this
embodiment,
where for some reason, outdoor air is not available for heat rejection from
the air cooled
condenser during air conditioning, the unit would have a water cooled
condenser 111
that could be employed in place of the air cooled condenser 73. The water
cooled
condenser 111 could be mounted alongside the pool water heat exchanger 93 or
in the
area of the pool water heat exchanger if one is not used. When operational,
the water
cooled condenser 111 would have a supply of water (not shown) hooked up to the
condenser with in and out lines 113, 115 with a suitable control valve 117 to
turn on the
water to run it through the condenser. A diverter valve 119 can be provided in
the line
79 to divert the refrigerant from the compressor 75, either before or after it
has passed
through the condenser 73, to the water cooled condenser 111 via a line 121 and
from
the water cooled condenser 111 back to the line 79 before entering the
evaporator. The
water cooled condenser 111 would operate when the air cooled condenser 73 was
not
operational. The outdoor air inlets would remain closed and the outside air
fan would be
inoperative. The diverter valve 119 and the water control valve 117 could both
be
operated from the control unit 81.
[1038] The unit can be modified to by removing the damper
assembly there from.
Without the damper assembly the unit could still be operated as an air
conditioning/
purging/ventilating unit. The modified unit could also still be used with a
pool water
heater and with a water cooled condenser if desired.
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