Friedrich M18CF User manual

DUCTLESS SPLIT SYSTEMS
AIR CONDITIONERS |HEAT PUMPS

Ductless splits are an innovative and ecient alternative
to window and thru-the-wall units. They have the benets
of a central system, without the diculty and expense of
installing ductwork. These are only a few of the benets
of ductless...
• Unobstructed window views.
• No need to uninstall and store unit during the winter.
• Independently-controlled zone cooling means up to four separate
indoor units working from a single outdoor unit.
• Save money by turning o units in unoccupied rooms.
• Set room temperatures based on individual preferences, instead of
one-size-ts-all.
simple installation
Friedrich ductless split systems have the
advantages of a ducted installation without
the high material and labor costs. Absolutely
no ductwork is required, so most systems
can be installed and running in a few hours.
SEER ratings up to 19.0
All Friedrich ductless models exceed the
federal 13.0 SEER requirements. And, a full
one-third of our models have super high
ratings ranging from 16.5 to 19.0 SEER
signicantly outperforming 13 SEER product
on energy savings.
extremely quiet
Ductless systems keep the operating noise
of the condensing unit outdoors, while
the blower fan of the indoor unit remains
whisper quiet.
Like a central system, without the ductwork.
TECHNOLOGY
INVERTER
all models use
R-410A
R E F R I G E R A N T
The ultimate room air conditioner
Easy to install. Exceptionally quiet.
Totally flexible.
The indoor unit and outdoor unit are
connected by refrigerant and power
lines, through a small three-inch hole
in the exterior wall.
electric wiring
refrigerant lines
OUTDOOR CONDENSER
transfers heat to the outdoors.
Compact unit can be placed
at ground level, hung on an
outside wall or placed on the
roof of a building
hard-wired
INDOOR UNIT
converts warm indoor
air to cold indoor air,
conditioning and
dehumidifying the room.
Unit is mounted high on
the wall.
REFRIGERANT LINES AND
ELECTRICAL pass through
a 3” wall opening and run
along the exterior of the
building to the condensing
unit. Electrical hard-wiring
is required.

zone 1
70° in
conference
room
zone 4
prefers
76°
zone 2
attending
seminar, unit
turned o
zone 3
constant
temperature
changes
Precise comfort from one
system in up to four dierent
rooms. That’s the beauty– and
eciency of a Friedrich Multi-
Zone system.
Commercial applications
including restaurant dining areas
and kitchens
setpoint
Initial
startup
2nd
startup
3rd
startup
1st
shutdown
2nd
shutdown
Inverter Technology Standard Technology
Standard Energy Usage
Inverter reaches
setpoint faster, then
adjusts capacity as
required to maintain
accurate temp
Inverter Energy Usage
multiple conguration choices
Over 20 single, dual, tri- and quad-zone systems provide a wide range of
heating and cooling options for even the toughest remodels, additions and
improvements. A new level of system exibility and control is at your ngertips
on Friedrich single and multi-zone systems.
advanced inverter technology
Inverter Technology lets you reach the desired temperature faster, maintain it
more accurately, and reduce energy costs. It eliminates constant compressor
start-ups/shut-downs
that traditional
technology requires
to maintain the set
temperature.
variable capacity
advantages
Inverter Technology
allows each system to
adjust capacity and
cooling output to
provide only the amount of cooling needed at a given time. For example, an
18,000 BTU/h system will operate even more eciently as a 15,500 if that is all
that’s needed.
Multi-zone flexibility.
commercial applications
• Room additions/renovations
• Homes without ductwork
• Bedrooms and family rooms
• Garage workshops
• Four season sunrooms
• Guest quarters
• Wine cellars
residential applications
• Computer rooms/server rooms
• Restaurant kitchen and prep areas
• Oces in warehouse spaces
• Storage facilities
• Buildings where security concerns prevent
the use of window units
• Internal areas without exterior wall access

Wall-mounted single zone
One wall-mounted indoor unit
connected to one outdoor unit.
features
• Auto swing louvers (up/down)
• Continuous ‘Air Sweep’
• Auto-restart after power interruptions
• Auto-shut flaps close when unit is off
for a sleeker appearance
• Washable, reusable air filters
• Removable front grille
• Auto-changeover (heat pump models)
Wall-mounted multi-zone heat pump
Two, three or four wall-mounted indoor
units connected to one outdoor unit.
features
• Auto swing louvers (up/down)
• Continuous ‘Air Sweep’
• Auto-restart after power interruptions
• Auto-shut flaps close when unit is off
• Washable, reusable air filters
• Removable front grille
• Auto-changeover
• Low-ambient operation
multi-zone cool/heat pump
zone 1 zone 2 zone 3 zone 4
model btu/h total btu seer
M18DYF 9500 9500 — — 19000 16.5
11000 11000 22000
M21DYF 9500 12000 — — 21500 16.5
11000 14000 25000
M24DYF 12000 12000 — — 24000 16.5
14000 14000 28000
M27TYF 9200 9200 9200 —27600 15.0
11200 11200 11200 33600
M30TYF 9300 9300 11800 —30400 15.0
11000 11000 14000 36000
M33TYF 9400 11800 11800 —33000 15.0
10700 13600 13600 37900
M36TYF1 9100 9100 17000 —35200 15.0
9800 9800 18400 38000
M36TYF2 11700 11700 11700 —35100 15.0
12700 12700 12700 38100
M36QYF 8800 8800 8800 8800 35200 15.0
9500 9500 9500 9500 38000
cool only
model btu/h seer
MO9CF 9700 14.3
M12CF 12300 13.5
M18CF 18000 19.0
M24CF 24200 18.0
M30CF 30700 15.0
cool/ heat pump
model btu/h seer
M09YF 9700
9600 14.3
M12YF 12300
12800 13.7
M18YF 18000
21600 19.0
M24YF 24200
27600 18.0
Pictured: Single zone model MW24CF indoor unit. Multi-zone system M36QYF.
Appearance varies by model.
Fully featured and fully
programmable for
total convenience
Auto-shut flaps close
when unit is off for a
sleeker appearance.
The continuous ‘Air
Sweep’ auto louvers
gently distribute cool or
warm air throughout
the room.
Auto-changeover on
heat pump models
automatically switches
the unit from cool to
heat; or from heat to
cool to maintain desired
temperature.
A multi-zone system
allows you to
condition up to four
rooms or areas.
Each indoor unit can
be independently
controlled for
optimum flexibility,
best comfort and
increased energy
savings.
wireless remote
• Remote for each indoor unit
• 24-hour timer and sleep timer
• Auto/cool/dry/fan/heat* modes
• Four fan speeds heating* or cooling:
high/medium/low/quiet, plus auto-fan
• Secured remote control holder
• Four different transmitter codes to prevent
unintentional interference with nearby units
* Heat pump models only
= cooling capacity
= heating capacity

TECHNOLOGY
INVERTER
Ceiling suspended heat/cool
Ceiling cassette heat pump
features
• Auto-swing louvers (up/down)
• Continuous ‘Air Sweep’
• Auto-restart after power
interruptions
• Auto-changeover
• Washable, reusable air filters
• Low-ambient operation
• Fresh air intake
• Two branch ducts for
adjoining rooms
(requires additional fan)
• Condensate pump: 31" lift
• Auto-shut flaps close when unit is off
wired remote
• Seven-day programmable on/off timer
controls up to 16 units– individually or
by zones
• Auto/cool/dry/fan/heat modes
• Self-diagnostics
• Three fan speeds heating or cooling:
high/medium/low, plus auto-fan
features
• Auto swing louvers (up/down, left/right)
• Continuous ‘Air Sweep’
• Auto-restart after power interruptions
• Auto-shut flaps
• Washable, reusable
air filters
• Fresh air capability
• Low-ambient operation
• Optional DP-36 condensate pump
low profile– 9 ¼" above ceiling
Floor/ceiling universal heat pump
Universal system may be located low
against the wall or on the ceiling.
features
• Auto swing louvers (up/down, left/right)
• Continuous ‘Air Sweep’
• Auto-restart after power interruptions
• Auto-shut flaps close when unit is off
for a sleeker appearance
• Washable, reusable air filters
• Fresh air capability
wireless remote
•24-hour timer and sleep timer
• Auto/cool/dry/fan/heat modes
• Three fan speeds heating or cooling:
high/medium/low, plus auto-fan
• Four different transmitter codes
• Secured remote control holder
• Self-diagnostics
mounts on the ceiling
or low against the wall
cool/ heat pump
S24YF 22,200 BTU/h 15.0 SEER
24,200 BTU/h
wireless remote
• 24-hour timer and sleep timer
• Auto/cool/dry/fan/heat modes
• Three fan speeds heating or
cooling: high/medium/low,
plus auto-fan
• Four dierent transmitter codes
• Secured remote control holder
• Self-diagnostics
91/4"
cool/ heat pump
C24YF 22,200 BTU/h 15.0 SEER
24,200 BTU/h
cool/ heat pump
S36YF 34,100 BTU/h 14.0 SEER
38,200 BTU/h

PERFORMANCE RATINGS
SYSTEM MODEL NO. M09YF M12YF M18YF M24YF
INDOOR MODEL MW09Y1F MW12Y1F MW18Y3F MW24Y3F
OUTDOOR MODEL MR09Y1F MR12Y1F MR18Y3F MR24Y3F
Capacity Cooling BTU/h 9700 12300 18000 24200
Capacity Heating @47°F BTU/h 9600 12800 21600 27600
Capacity Heating @17°F BTU/h 7600 9900 16600 21000
HSPF 8.2 8.2 10 10
SEER 14.3 13.7 19.0 18.0
Moisture Removal Pts/h 2.1 3.2 5.9 5.3
Airflow (Quiet, Low, Med, High) CFM 185/220/260/295 215/250/305/355 240/290/355/415 380/450/560/650
Sound Rating - Indoor dB-A 26/31/36/40 28/35/40/45 25/32/38/44 32/36/41/47
Sound Rating - Outdoor dB-A 43 45 50 52
Operating Range COOL (HEAT) °F 0 - 115 (17-75) 0 - 115 (17-75) 0 - 115 (5-75) 0 - 115 (5-75)
ELECTRICAL DATA
Power Source 115-60-1 115-60-1 230/208-60-1 230/208-60-1
Min. Ampacity A12 15 16 21
Cooling Watts W820 1070 1730 2310
Max. TD Fuse/Breaker A15 20 20 30
REFRIGERATION SYSTEM
Refrigerant R410A R410A R410A R410A
Compressor Type Rotary Rotary Inverter Inverter
Connections Flare Flare Flare Flare
Liquid Line O.D. in 1/4 1/4 1/4 1/4
Suction Line O.D. in 3/8 3/8 1/2 5/8
Factory Precharge ft 25 25 49 49
Max. Line Length ft 49 49 66 98
Max. Height Difference ft 26 26 49 66
DIMENSIONS & WEIGHT
INDOOR UNIT
W x H x D in 31 1/8x 10 7/8x 8 1/231 1/8x 10 7/8x 8 1/231 1/8x 10 7/8x 8 1/239 1/4x 12 5/8x 9
Net Weight lbs 21 21 21 31
Shipping Weight lbs 26 26 26 40
OUTDOOR UNIT
W x H x D in 31 1/8x 21 1/4x 11 3/831 1/8x 21 1/4x 11 3/831 1/8x 22 3/4x 12 3/831 1/8x 22 3/4x 12 3/8
Net Weight lbs 71 79 88 97
Shipping Weight lbs 79 88 98 106
PERFORMANCE RATINGS
SYSTEM MODEL NO. M09CF M12CF M18CF M24CF M30CF
INDOOR MODEL MW09C1F MW12C1F MW18C3F MW24C3F MW30C3F
OUTDOOR MODEL MR09C1F MR12C1F MR18C3F MR24C3F MR30C3F
Capacity Cooling BTU/h 9700 12300 18000 24200 30700
SEER 14.3 13.5 19.0 18.0 15.0
Moisture Removal Pts/h 2.1 3.2 5.9 5.3 9.7
Airflow (Quiet, Low, Med, High) CFM 185/220/260/295 215/250/305/355 240/290/355/415 380/450/560/650 380/450/560/650
Sound Rating - Indoor dB-A 26/31/36/40 28/35/40/45 25/32/38/44 32/36/41/47 32/36/41/47
Sound Rating - Outdoor dB-A 43 45 50 52 53
Operating Range °F 0 - 115 0 - 115 0 - 115 0 - 115 0 - 115
ELECTRICAL DATA
Power Source 115-60-1 115-60-1 230/208-60-1 230/208-60-1 230/208-60-1
Min. Ampacity A12 15 16 21 22
Cooling Watts W820 1060 1730 2310 3460
Max. TD Fuse/Breaker A15 20 20 30 30
REFRIGERATION SYSTEM
Refrigerant R410A R410A R410A R410A R410A
Compressor Type Rotary Rotary Inverter Inverter Inverter
Connections Flare Flare Flare Flare Flare
Liquid Line O.D. in 1/4 1/4 1/4 1/4 3/8
Suction Line O.D. in 3/8 3/8 1/2 5/8 5/8
Factory Precharge ft 25 25 49 49 66
Max. Line Length ft 49 49 66 98 164
Max. Height Difference ft 26 26 49 66 98
DIMENSIONS & WEIGHT
INDOOR UNIT
W x H x D in 31 1/8x 10 7/8x 8 1/231 1/8x 10 7/8x 8 1/231 1/8x 10 7/8x 8 1/239 1/4x 12 5/8x 9 39 1/4x 12 5/8x 9
Net Weight lbs 21 21 21 31 31
Shipping Weight lbs 26 26 26 40 40
OUTDOOR UNIT
W x H x D in 31 1/8x 21 1/4x 11 3/831 1/8x 21 1/4x 11 3/831 1/8x 22 3/4x 12 3/831 1/8x 22 3/4x 12 3/835 3/8x 32 5/8x 13
Net Weight lbs 68 77 88 97 137
Shipping Weight lbs 77 86 98 106 155
Inverter model
wall mounted cooling
wall mounted heat pumps

PERFORMANCE RATINGS
SYSTEM MODEL NO. M27TYF M30TYF M33TYF M36TYF1 M36TYF2
INDOOR MODEL 3 x MW09Y3FM 2 x MW09Y3FM MW12Y3FM MW09Y3FM 2 x MW12Y3FM 2 x MW09Y3FM MW18Y3FM 3 x MW12Y3FM
OUTDOOR MODEL MR36TQY3F MR36TQY3F MR36TQY3F MR36TQY3F MR36TQY3F
Capacity Cooling BTU/h 9200 ea. 9300 ea. 11800 9400 11800 ea. 9100 ea. 17000 11700 ea.
Capacity Heating @ 47°F BTU/h 11200 ea. 11000 ea.14000 10700 13600 ea. 9800 ea.18400 12700 ea.
Capacity Heating @ 17°F BTU/h 8300 ea. 7700 ea. 9800 7200 9200 ea. 6700 ea. 12500 8600 ea.
HSPF 9.0 9.0 9.0 9.0 9.0
SEER 15.0 15.0 15.0 15.0 15.0
Moisture Removal Pts/h 2.9 ea. 2.9 ea. 3.7 2.9 3.7 ea. 2.9 ea. 5.7 3.7 ea.
Airflow (Quiet, Low, Med, High) CFM 185/220/260/295 185/220/260/295 215/250/305/355 185/220/260/295 215/250/305/355 185/220/260/295 240/290/355/415 215/250/305/355
Sound Rating - Indoor dB-A 27/29/33/37 27/29/33/37 30/34/39/42 27/29/33/37 30/34/39/42 27/29/33/37 33/39/42/46 30/34/39/42
Sound Rating - Outdoor dB-A 52 52 52 52 52
Operating Range COOL (HEAT) °F 0 - 115 (14-75) 0 - 115 (14-75) 0 - 115 (14-75) 0 - 115 (14-75) 0 - 115 (14-75)
ELECTRICAL DATA (all indoor units receive power from outdoor unit; values listed are total)
Power Source 230/208-60-1 230/208-60-1 230/208-60-1 230/208-60-1 230/208-60-1
Min. Ampacity A 22.5 22.5 22.5 22.5 22.5
Cooling Watts W 2710 3180 3710 4000 3980
Max. TD Fuse/Breaker A 30 30 30 30 30
REFRIGERATION SYSTEM
Refrigerant R410A R410A R410A R410A R410A
Compressor Type Inverter Inverter Inverter Inverter Inverter
Connections Flare Flare Flare Flare Flare
Liquid Line O.D. in 1/4 1/4 1/4 1/4 1/4 1/4
Suction Line O.D. in 3/8 3/8 3/8 3/8 1/2 3/8
Factory Precharge ft 165 165 165 165 165
Max. Line Length ft Each unit:82 Total:230 Each unit:82 Total:230 Each unit:82 Total:230 Each unit:82 Total:230 Each unit:82 Total:230
Max. Height Difference ft 49 49 49 49 49
DIMENSIONS & WEIGHT
INDOOR UNIT
W x H x D in 31 1/8x 10 7/8x 8 1/2ea. 31 1/8x 10 7/8x 8 1/2ea. 31 1/8x 10 7/8x 8 1/231 1/8x 10 7/8x 8 1/231 1/8x 10 7/8x 8 1/231 1/8x 10 7/8x 8 1/2
Net Weight lbs 21 ea. 21 ea. 21 21 21 ea. 21 ea. 21 21 ea.
Shipping Weight lbs 26 ea. 26 ea. 26 26 26 ea. 26 ea. 26 26 ea.
OUTDOOR UNIT
W x H x D in 35 3/8x 32 5/8x 13 35 3/8x 32 5/8x 13 35 3/8x 32 5/8x 13 35 3/8x 32 5/8x 13 35 3/8x 32 5/8x 13
Net Weight lbs 159 159 159 159 159
Shipping Weight lbs 172 172 172 172 172
PERFORMANCE RATINGS
SYSTEM MODEL NO. M18DYF M21DYF M24DYF M36QYF
INDOOR MODEL 2 x MW09Y3FM MW09Y3FM MW12Y3FM 2 x MW12Y3FM 4 x MW09Y3FM
OUTDOOR MODEL MR24DY3F MR24DY3F MR24DY3F MR36TQY3F
Capacity Cooling BTU/h 9500 ea. 9500 ea. 12000 12000 ea. 8800 ea.
Capacity Heating @ 47°F BTU/h 11000 ea. 11000 ea. 14000 14000 ea. 9500 ea.
Capacity Heating @ 17°F BTU/h 9500 ea. 9500 ea. 11000 10500 ea. 6600 ea.
HSPF 9.0 9.0 9.0 9.0
SEER 16.5 16.5 16.5 15.0
Moisture Removal Pts/h 2.9 ea. 2.9 ea 3.7 ea. 3.7 ea. 2.9 ea.
Airflow (Quiet, Low, Med, High) CFM 185/220/260/295 185/220/260/295 215/250/305/355 215/250/305/355 185/220/260/295
Sound Rating - Indoor dB-A 27/29/33/37 27/29/33/37 30/34/39/42 30/34/39/42 27/29/33/37
Sound Rating - Outdoor dB-A 52 52 52 52
Operating Range COOL (HEAT) °F 0 - 115 (14-75) 0 - 115 (14-75) 0 - 115 (14-75) 0 - 115 (14-75)
ELECTRICAL DATA (all indoor units receive power from outdoor unit; values listed are total)
Power Source 230/208-60-1 230/208-60-1 230/208-60-1 230/208-60-1
Min. Ampacity A 15 15 15 22.5
Cooling Watts W 1600 1900 2300 3900
Max. TD Fuse/Breaker A 20 20 20 30
REFRIGERATION SYSTEM
Refrigerant R410A R410A R410A R410A
Compressor Type Inverter Inverter Inverter Inverter
Connections Flare Flare Flare Flare
Liquid Line O.D. in 1/4 1/4 1/4 1/4 1/4
Suction Line O.D. in 3/8 3/8 3/8 3/8 3/8
Factory Precharge ft 98 98 98 165
Max. Line Length ft Each unit:82 Total:98 Each unit:82 Total:98 Each unit:82 Total:98 Each unit:82 Total:230
Max. Height Difference ft 33 33 33 49
DIMENSIONS & WEIGHT
INDOOR UNIT
W x H x D in 31 1/8x 10 7/8x 8 1/2ea. 31 1/8x 10 7/8x 8 1/2ea. 31 1/8x 10 7/8x 8 1/2ea. 31 1/8 x 10 7/8 x 8 1/2 ea.
Net Weight lbs 21 ea. 21 21 21 ea. 21 ea.
Shipping Weight lbs 26 ea. 26 26 26 ea. 26 ea.
OUTDOOR UNIT
W x H x D in 35 3/8x 32 5/8x 13 35 3/8x 32 5/8x 13 35 3/8x 32 5/8 x 13 35 3/8 x 32 5/8 x 13
Net Weight lbs 151 151 151 159
Shipping Weight lbs 164 164 164 172
dual-zone heat pumps quad-zone heat pumps
tri-zone heat pumps
inverter model

USED WITH: LENGTH-FT. LIQUID SUCTION KIT#
All 9000 and 12000 BTU/h
Indoor Units
15 1/4” 3/8” T32150
35 1/4” 3/8” T32350
All 18000 BTU/h Indoor Units 15 1/4” 1/2” T42150
35 1/4” 1/2” T42350
All MW24Y3F and MW24C3F Units 15 1/4” 5/8” T52150
35 1/4” 5/8” T52350
All 30000 BTU/h Indoor Units and
S24YF, S36YF and C24YF Units
15 3/8” 5/8” T53150
35 3/8” 5/8” T53350
floor/ceiling universal ceiling suspended ceiling cassette
PERFORMANCE RATINGS
SYSTEM MODEL NO. S24YF S36YF C24YF
INDOOR MODEL MS24Y3F MS36Y3F MC24Y3F
OUTDOOR MODEL MR24UY3F MR36Y3F MR24UY3F
Capacity Cooling BTU/h 22200 34100 22200
Capacity Heating @47°F BTU/h 24200 38200 24200
Capacity Heating @17°F BTU/h 20100 27100 20100
HSPF 8.5 8.5 8.5
SEER 15.0 14.0 15.0
Moisture Removal Pts/h 7.4 7.4 6.4
Airflow (Low, Med, High) CFM 371/436/518 842/977/1089 436/536/618
Sound Rating - Indoor dB-A 38/43/47 41/45/48 38/43/45
Sound Rating - Outdoor dB-A 53 54 53
Operating Range COOL (HEAT) °F 0 to 115 (14-75) 0 to 115 (14-75) 0 to 115 (14-75)
ELECTRICAL DATA
Power Source 230/208-60-1 230/208-60-1 230/208-60-1
Min. Ampacity A 15.5 23 15.5
Cooling Watts W 2250 4220 2100
Max. TD Fuse/Breaker A 20 30 20
REFRIGERATION SYSTEM
Refrigerant R410A R410A R410A
Compressor Type Inverter (Twin Rotary) Inverter (Twin Rotary) Inverter (Twin Rotary)
Connections Flare Flare Flare
Liquid Line O.D. in 3/8 3/8 3/8
Suction Line O.D. in 5/8 5/8 5/8
Factory Precharge ft 50 50 50
Max. Line Length ft 165 165 165
Max. Height Difference ft 66 98 66
DIMENSIONS & WEIGHT
INDOOR UNIT
W x H x D in 39 x 7 7/8x 25 3/465 3/8x 9 1/2x 27 1/232 5/8x 9 5/8x 32 5/8
Net Weight lbs 62 106 75
Shipping Weight lbs 82 134 97
OUTDOOR UNIT
W x H x D in 35 3/8x 32 5/8x 13 35 3/8x 32 5/8x 13 35 3/8x 32 5/8x 13
Net Weight lbs 141 141 141
Shipping Weight lbs 154 154 154
Friedrich Air Conditioning Co. | P.O. Box 1540 | San Antonio, TX 78295-1540 | [phone] | fax [phone] | www.friedrich.com
DSS-08 Printed in USA
Insulated line sets are available for all Friedrich split systems in 15 ft. and 35 ft. lengths. Each line set is equipped with flare nuts on both ends. Both liquid and
suction lines are insulated. Line sets can be joined together with field supplied double female connectors. Each system requires one line set for each indoor
unit installed. On multi-zone systems, line sets should be ordered based on individual indoor unit capacities not total system capacity. For example, a M18DYF
uses 2 line sets for 9,000 btu units, not 1 for the 18,000 btu product.
DRAIN PUMP USED WITH
DP-36 S36YF
NOTE: All models have low ambient capabilities built-in. Capacity is reduced as 0 degrees Fahrenheit is approached.
NOTE: All R410A models have 1/2˝ UNF 20 thread per inch charging and vacuuming ports. An adapter must be used
for 1/4˝ gauges. Adapter part number 67270018 is available through Friedrich parts distributors.
all models use
R-410A
R E F R I G E R A N T
inverter model
ceiling and oor/ceiling universal heat pumps
refrigeration line sets