nuair WINDSOR SERIES Assembly instructions

Rev. 2.3 Aug. 19, 2104
P.O. Box 2758
Windsor, Nova Scotia, B0N 2T0
Phone: [phone] Fax: [phone]
www.nu-airventilation.com
Email: [email protected]
WINDSOR SERIES
O
OP PE ER RA AT TI IN NG G, , M MA AI IN NT TA AI IN NI IN NG G & & I IN NS ST TA AL LL LI IN NG G Y YO OU UR R H HE EA AT T R RE EC CO OV VE ER RY Y
V
VE EN NT TI IL LA AT TO OR R
FOR MODELS NU145, NU165, NU205
* LEAVE THIS DOCUMENT WITH THE HOMEOWNER
Specifications, dimensions and ratings may change without notice
as a result of ongoing product development and improvements.

Rev. 2.3 Aug. 19, 2104
NOTE
Prior to integrating this unit with any other piece of mechanical equipment, i.e. furnace, air handler, combustion
heating appliance, careful consideration must be given to system design and integration to ensure compatibility
and proper operation of both appliances. Do not connect the duct system of your H/ERV to any clothes dryer or
kitchen exhaust fan duct system.
Whether installing this unit as part of an independent system or to integrate it with a central heating/cooling
system, use the procedure in this manual to ensure that the air flows of the H/ERV are balanced. Only a properly
balanced H/ERV will deliver maximum performance and energy efficiency.
Although this document contains guidelines for proper HRV sizing and installation, your ventilation system should
be installed in conformance to the appropriate provincial or state building regulations or National Building Code
and/or ASHRAE “Good Engineering Practices”.
IMPORTANT
PLEASE READ THIS MANUAL BEFORE YOU INSTALL OR SERVICE UNIT
AVOID RISK OF INJURY, ELECTRIC SHOCK AND FIRE HAZARD
DO NOT install this product in an unconditioned space—15º C/59º F ambient temperature is recommended—or in a
space/manner where maintenance and service might a pose risk of personal injury or damage to this product.
For indoor installations only.
Your H/ERV is equipped with a 3-prong plug which will fit an A/C electrical outlet in just one orientation. Do not alter this
plug or its cord in any way. Grip the plug firmly when removing it from an electrical outlet—NEVER unplug this product by
pulling or twisting its power cord.
ALWAYS unplug an H/ERV before you open or remove its cover (door) to clean the inside of the unit or for any other
servicing or repairs.
The cover to this H/ERV is removable to ensure ease of access to internal components during cleaning and servicing.
USE CAUTION when opening or removing the cover of this H/ERV to avoid risk of personal injury or damage to the cover.
NEVER attempt to clean the interior of this H/ERV or its components while the unit is plugged in or running.
ONLY qualified persons should attempt repair or service of any electrical/internal component of this product.
NEVER attempt to repair or service any internal component of this H/ERV while the unit is plugged in or running.
DO NOT use your ventilation system to exhaust flammable fumes or gasses.
ALWAYS contact your Nu-Air representative if you have any questions or comments about the operation or maintenance
of your Nu-Air H/ERV—we are here to help you!

Rev. 2.3 Aug. 19, 2104
TABLE OF CONTENTS
1. PERFORMANCE RATINGS & PHYSICAL DATA .....................................................................................................3
2. HOW THE NU-AIR SYSTEM WORKS......................................................................................................................... 6
3. INSTALLATION.............................................................................................................................................................6
3.1. Installer's Responsibilities........................................................................................................................6
3.2. Installation System Options ....................................................................................................................7
3.3. Ducting to The Outside.............................................................................................................................9
3.4. Mounting & Noise Control.....................................................................................................................10
3.5. Ductwork .................................................................................................................................................10
3.6. Drain Connections ..................................................................................................................................10
3.7. Balancing the System: High and Low Speed........................................................................................12
4. CONTROLS...................................................................................................................................................................13
4.1. Main Board Features..............................................................................................................................14
4.2. ES Series Controls (12 VDC).................................................................................................................15
4.3. Windsor Series Controls & Other 24 V Control Options ...................................................................17
4.4. Furnace Interlock....................................................................................................................................18
5. START-UP..................................................................................................................................................................... 18
6. OPERATING HINTS.................................................................................................................................................... 18
7. MAINTENANCE ..........................................................................................................................................................19
7.5. Filters .......................................................................................................................................................19
7.6. Fans..........................................................................................................................................................19
7.7. Condensate Drain....................................................................................................................................19
7.8. Heat/Energy Recovery Core ..................................................................................................................19
7.9. Exterior Hoods........................................................................................................................................19
7.10. Grills & Duct Work...........................................................................................................................19
8. ANNUAL SERVICING: ...............................................................................................................................................19
9. TROUBLE SHOOTING ...............................................................................................................................................20
10. ELECTRICAL SCHEMATICS .................................................................................................................................... 21
10.11. ES Series Wiring Diagrams...............................................................................................................21
10.12. Altering Furnace Interlock Settings.................................................................................................22
10.13. Unit Control Board: Status LEDs & Remote Control Connections..............................................23
10.14. ES Series Control Wiring..................................................................................................................23
10.15. DSTAT-1 Control Wiring.................................................................................................................24
10.16. WIN-1 Control Wiring......................................................................................................................24
10.17. WIN-20 Control Wiring....................................................................................................................25
10.18. Remote On/Off (Two-Wire) Switching............................................................................................25
11. WARRANTIES.............................................................................................................................................................. 26

Nu-Air Ventilation Systems Inc. - HRV Operating & Installation Manual
Rev. 2.3 Aug. 19, 2014 - 3 -
VENTILATION PERFORMANCE
ENERGY PERFORMANCE
EXT.
STATIC
NET SUPPLY
GROSS AIR FLOW
SUPPLY
NET
POWER
SENSIBLE
APPARENT
PRESSURE
AIR FLOW
SUPPLY
EXHAUST
TEMP.
AIR FLOW
CONSUMED
RECOVERY
SENSIBLE
in wg (Pa)
cfm (l/s)
cfm (l/s)
cfm (l/s)
ºF (ºC)
cfm (l/s)
Watts
EFFICIENCY
EFFECTIVENESS
0.1 (25)
173 (81)
180 (84)
193 (91)
+32 (0)
61 (29)
54
63
75
0.2 (50)
159 (75)
165 (78)
175 (82)
+32 (0)
85 (40)
66
62
72
0.3 (75)
146 (68)
151 (71)
159 (75)
+32 (0)
114 (54)
94
61
70
0.4 (100)
132 (62)
137 (65)
144 (68)
0.5 (125)
119 (56)
123 (58)
130 (61)
13 (-25)
62 (29)
58
65
78
0.6 (150)
105 (49)
109 (51)
116 (55)
0.7 (175)
90 (42)
94 (44)
103 (48)
1. PERFORMANCE RATINGS & PHYSICAL DATA
Model: NU165
ELECTRICAL: 120V/1/60 Hz. 128W, 1.1A

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Rev. 2.3 Aug. 19, 2014 - 4 -
VENTILATION PERFORMANCE
ENERGY PERFORMANCE
EXT.
STATIC
NET SUPPLY
GROSS AIR FLOW
SUPPLY
NET
POWER
SENSIBLE
APPARENT
PRESSURE
AIR FLOW
SUPPLY
EXHAUST
TEMP.
AIR FLOW
CONSUMED
RECOVERY
SENSIBLE
in wg (Pa)
cfm (l/s)
cfm (l/s)
cfm (l/s)
ºF (ºC)
cfm (l/s)
Watts
EFFICIENCY
EFFECTIVENESS
0.1 (25)
143 (67)
144 (68)
174 (82)
+32 (0)
64 (30)
50
71
80
0.2 (50)
124 (58)
125 (59)
150 (71)
+32 (0)
96 (45)
80
64
73
0.3 (75)
109 (51)
110 (52)
135 (64)
+32 (0)
116 (55)
90
63
70
0.4 (100)
100 (47)
101 (48)
122 (58)
0.5 (125)
92 (43)
93 (44)
104 (49)
13 (-25)
60 (28)
69
64
82
0.6 (150)
78 (37)
79 (37)
93 (44)
0.7 (175)
63 (30)
64 (30)
86 (41)
0.8 (200)
46 (22)
47 (22)
72 (34)
MODEL: NU145
ELECTRICAL: 120V/1/60 Hz. 100W, 0.9A
This product earned the ENERGY STAR® by meeting strict energy efficiency guidelines set by Natural
Resources Canada and the US EPA. It meets ENERGY STAR requirements only when used in Canada.

Nu-Air Ventilation Systems Inc. - HRV Operating & Installation Manual
Rev. 2.3 Aug. 19, 2014 - 5 -
VENTILATION PERFORMANCE
ENERGY PERFORMANCE
EXT.
STATIC
NET
SUPPLY
GROSS AIR FLOW
SUPPLY
NET
POWER
SENSIBLE
APPARENT
PRESSURE
AIR FLOW
SUPPLY
EXHAUST
TEMP.
AIR
FLOW
CONSUMED
RECOVERY
SENSIBLE
in wg (Pa)
cfm (l/s)
cfm (l/s)
cfm (l/s)
ºF (ºC)
cfm (l/s)
Watts
EFFICIENCY
EFFECTIVENESS
0.1 (25)
227 (107)
230 (108)
282 (133)
+32 (0)
65 (31)
72
70
81
0.2 (50)
203 (96)
206 (97)
262 (124)
+32 (0)
97 (46)
82
66
74
0.3 (75)
194 (92)
196 (93)
244 (115)
+32 (0)
107 (51)
86
65
73
0.4 (100)
177 (84)
179 (84)
222 (105)
0.5 (125)
162 (77)
164 (78)
206 (97)
13 (-25)
91 (43)
89
62
77
0.6 (150)
149 (70)
150 (71)
188 (89)
0.7 (175)
130 (62)
132 (62)
165 (78)
0.8 (200)
115 (54)
116 (55)
144 (68)
0.9 (225)
91 (43)
92 (43)
125 (59)
1.0 (250)
77 (36)
77 (37)
98 (46)
MODEL: NU205
ELECTRICAL: 120V/1/60 Hz. 156W, 1.0 A
This product earned the ENERGY STAR® by meeting strict energy efficiency guidelines set by Natural
Resources Canada and the US EPA. It meets ENERGY STAR requirements only when used in Canada.

Nu-Air Ventilation Systems Inc. - HRV Operating & Installation Manual
Rev. 2.3 Aug. 19, 2014 - 6 -
2. HOW THE NU-AIR SYSTEM WORKS
A. Powerful, centrifugal
blowers bring fresh air into
your home while an equal
amount of stale, humid air is
exhausted to the outside.
This is NU-AIR’s balanced
central ventilation system.
B. Incoming fresh air is filtered
before flowing through the
heat exchange core.
C. Stale, humid air flows
through the cross-flow heat
exchanger and transfers the
heat to the incoming fresh
air.
D. Warm fresh air is distributed to each room of the house through an independent ductwork system.
3. INSTALLATION
3.0.1. Installation Supplies, Standard Issue Items:
The HRV comes equipped with:
Filters
Anti-Vibration Straps
Heat Recovery Core
Drain Hose Assembly
Balancing dampers are NOT REQUIRED. Windsor Series HRVs from Nu-Air are equipped with
a system which allows the installer to adjust each motor in both high and low speed.
Removable terminal blocks for timers, remote controls, furnace interlock. A 4-wire terminal
block for 12 VDC ES Series controls and a 10-wire terminal block for 24 V controls are provided
with the unit. To use these, gently remove the block from the HRV, fit the wire into place and secure
it in its trap, using a fine-tipped flat-headed screwdriver.
3.1. Installer's Responsibilities
Installers are responsible for the performance of the ventilation system and for ensuring that all codes
and standards are met.
Do not mount the fresh air supply near a source of contaminated air such as automotive exhaust, gas
or propane exhaust, garbage containers or oil tanks.
Do not connect a dryer exhaust to an HRV.
Combustion appliances such as furnaces and hot water heaters must not draw combustion air directly
from an HRV.
Do not connect a kitchen range hood to any part of this system.
Do not install in attics or other unconditioned spaces (min. 16º C).
Do not install in enclosed garages.
Try to maintain straight duct runs as much as possible, using as few joint fittings as possible.

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Keep use of flexible ducting to a minimum.
Be sure to observe local codes regarding running and insulating ducts in unconditioned spaces.
Poorly insulated ducts run in unconditioned spaces will hamper the efficiency of the HRV.
Sizing the System
For residential applications you should have a minimum ventilation capacity of 10 cfm (5 L/s) per room.
The chart that accompanies the flow grid calibrates pressure readings to airflow. Refer to ASHRAE
Standard 62 for acceptable ventilation rates in commercial buildings.
Calculating TVC (Total ventilation Capacity) for Residential Applications:
20 cfm for the master bedroom
20 cfm for an unfinished basement
10 cfm for each other room in the house
Add these together to arrive at your TVC.
This method is called the “Room Count Method” and is part of CSA F326 (Residential Mechanical
Ventilation Systems). 0.3 air change per hour is no longer used.
Areas typically serviced by Fresh Air: Bedrooms, Living Rooms, Dining Areas, and Recreation Areas.
Areas typically serviced by Exhaust Air: Laundry Rooms, Kitchens, Bathrooms, other wet rooms.
Note
Kitchen exhaust grills should be equipped with a grease filter and must be located at least 3 ft.
horizontally in all directions from the surface of the range extended to the ceiling.
3.2. Installation System Options
Before installing your HRV, please read these
instructions for correct installation. The Nu-Air HRV
is a self-contained system that is ready to be installed.
There are three commonly used and approved
methods of installation.
3.2.1. The Fully Ducted System
This system uses an independent duct system for
supply and exhaust air. The HRV is controlled
independently of all other equipment.
The best results are achieved when:
Each room of the space is serviced with a vent
mounted in the ceiling or high on an interior wall (within 12" of the ceiling).
Vents are located deep within a room, where they will not short circuit or create an
uncomfortable draft.

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3.2.2. The Extended Exhaust System
This system uses the HRV in conjunction with a
forced air furnace distribution system. In this
system the HRV supply air to the house is
introduced into the return duct of the forced air
furnace. Separate, additional ductwork is used to
transfer stale air from the wet rooms to the HRV.
3.2.3. Extended System, Continuous Ventilation
The furnace fan may not need to run continuously
with this system. Check local code requirements. For improved supply air distribution during
continuous ventilation mode, the furnace may be interlocked to the HRV. See Section 4.4 for wiring
instructions and Section 10.12 for interlock settings.
3.2.4. Extended System, Intermittent Ventilation
If the HRV is operated intermittently, the furnace fan should be interlocked with the HRV for good
distribution of supply air during high-speed
ventilation conditions.
3.2.5. The Simplified System
This system uses the furnace's return plenum
for both supply air distribution and exhaust
air collection. The exhaust air connection
must be a minimum of 40 inches upstream
of the supply air connection to avoid short-
circuiting of the fresh air.
3.2.5.1. Simplified System - Continuous Ventilation & Intermittent Operation
For proper supply air distribution with this system, and to prevent short circuiting in the return air duct,
the furnace fan must run during ventilation mode. Interlock the furnace and HRV in accordance with
Sections 4.4 (wiring) and 10.12 (settings).
INSTALLATION NOTES:
1) When selecting an installation option, consideration should be given to the increased electrical
consumption of the furnace fan. The way that your Heat/Energy-recovery ventilator is installed may
make a significant difference to the electrical energy that you will use. To minimize the electricity use of
the Heat/Energy-recovery ventilator, a stand-alone fully ducted installation is recommended. If you
choose a simplified installation that operates your furnace air handler for room-to-room ventilation, an
electrically efficient furnace that has an electronically commutated (EC) variable speed blower motor
will minimize your electrical energy consumption and operating cost.

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2) In cases where the HRV is coupled with a central air handling system, the HRV fresh air supply duct
to the return air plenum shall be connected at a sufficient distance upstream of the plenum connection to
the furnace. This allows proper mixing and ensures appropriate air temperature at the furnace heat
exchanger in cold weather. For fuel-fired mid and high efficiency furnaces a minimum temperature of
15.5º C (60º F) is recommended at the heat exchanger. (Check the furnace manufacturer’s
specifications).
3) To ensure quiet operation of ENERGY STAR qualified HRV/ERVs, each product should be installed
using sound attenuation techniques, such as using a flexible connector between the unit and the rigid-
pipe supply and return ducts.
4) Installing a user-accessible control with your product will improve comfort and may significantly
reduce the product’s energy use. Most building codes require a centrally located control with an on/off
switch.
3.3. Ducting to The Outside
Between the weather hoods and the HRV you must use fully insulated ducting with an integrated
vapour barrier. Insulated ducting with an integrated vapour barrier must also be used on all runs
passing through unheated areas. This will help avoid condensation problems and energy losses.
The minimum RSI value of insulation should equal that of the local building codes.
3.3.1. Weather Hood Installation
1. Insulated flex duct slides over the
galvanized sleeve of the weather hood.
2. Use sheathing tape (red) to join the inner
duct to the hood's sleeve.
3. Tape the vapour barrier to back of the hood
without compressing the insulation. Caulk
or foam seal around the collars and hoods to
eliminate air and water leaks.
4. Locate the hoods for easy access to the bird
screen for cleaning purposes.
5. Be sure to use exterior sealant along the top
and side edges of the hoods, tooling the
sealant to ensure a good seal.
Make the insulated duct that connects the weather hoods to the HRV as short as possible to minimize
airflow restrictions. Avoid sharp bends and stretch out the inner lining of the flex duct as much as
possible to reduce static pressure and maximize airflow. For runs over 12’, increasing flex diameter 1”
to next size up will reduce pressure drop in the duct.
3.3.1.1. Locating the Weather Hoods
There should be a minimum of 6’ (feet) of separation between the fresh air and exhaust hoods. Supply
hoods should be a minimum of 18” (inches) above the ground level. Exhaust hoods should be at least 4”
(inches) above the ground level. Holes through the wall should be 1” larger than the collar on the hood,
to allow for insulation. Fresh air hoods must be 3’ away from any other appliance exhaust vent or
furnace vent.

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In addition ASHRAE Standard 62-99 recommends the following. Ventilation systems should be
designed to prevent the reintroduction of exhaust contaminants, condensation or freeze-ups and growth
of microorganisms. Make-up air inlets and exhaust air outlets shall be located to avoid contamination of
the makeup air. Contaminants from sources such as cooling towers, sanitary vents, vehicular exhaust,
and street traffic should be avoided. Consult local code requirements for minimum distances.
3.4. Mounting & Noise Control
For maximum efficiency, the HRV should be installed in a heated
area. The HRV is designed to be hung from the ceiling by way of the
anti-vibration straps supplied. Avoid hanging the HRV directly below
a bedroom or other quiet area.
Connecting To Other Equipment - Residential Applications
Interconnection with a forced air furnace duct system is
permissible (see Section 4.4); however, your Nu-Air HRV is not
intended to be connected to any other equipment or appliances.
Flexible ducting may be desired in some installations for noise
abatement. To ensure effective air flow, use only as much
flexible ducting as necessary and keep it taut.
3.5. Ductwork
An engineer or other qualified person should design the duct
system.
Duct runs should be straight with minimum bends and elbows.
Ensure joints are tight-fitting and sealed with duct tape or sealer.
Use galvanized duct whenever possible. Although flexible duct
can be used, its use should be restricted to areas indicated (to
outside hoods and in unheated spaces).
All ducting must be supported every 3’ or less.
Be sure to seal all pipe joints with foil tape or a duct sealant.
When possible, form elbow joints so that they are as straight as
possible.
3.6. Drain Connections
Access to a drain or sump is required to handle the HRV condensate. Care should be taken to run the
condensate tube where it cannot freeze.
For best results, Nu-Air recommends the following steps be followed when installing drain kits on residential
HRV's.
1. Apply the rubber O-ring supplied to the flange of each drain spout (A)

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2. Insert the drain spouts through the holes in the drain pan (B)
3. Use the provided nut to tightlysecure the drain spout
4. Cut two lengths of drain hose (E) long enough to avoid kinking
5. Attach the hose to the drain spout by sliding it over the spout until it is tight to the bottom of the speed nut.
Repeat for the other side
6. Secure the hose to the spout with the plastic tie wraps (D)
7. Install the Tee (F) in either of the two ways shown in the drawings below
8. Attach the free end of the hose to the left fitting. Repeat for the other side
9. Use the remaining hose to form a "P" trap and terminate at the top of the tee
10. Pour approximately one cup of water into the drain assembly to form an air seal. This prevents gasses
from being drawn into the HRV/ERV
Note for Single-Drain Units
Your unit might be equipped with just one drain and one drain plug. For these models, use the drain hose to
form a P-shape after connecting the hose to the drain plug (the arc of the P should be wide enough so as not to
cause a kink in the drain hose). Fix the P-shape with one of the (two) plastic cable-ties provided, taking care not
to pinch the hose when tightening the cable-tie.

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3.7. Balancing the System: High and Low Speed
Balanced air flow between the supply and exhaust air streams is essential to the performance of an HRV
or ERV. With the Windsor Series, changing motor speeds or balancing is quick and simple with two
buttons recessed slightly into the unit’s cabinet. NO BALANCING DAMPERS ARE REQUIRED. Be
sure to close windows and doors, and turn off all exhaust fans/appliances during the balancing
procedure.
For High-Speed Adjustment/Balancing, use the following procedure:
1. Use any means to initiate high speed (e.g. ES-M1, R—Hi jumper wire, or 24V R—Hi control)
may be used.
2. Press and hold either the FRESH air or EXHAUST air pushbuttons (not both) for 3 Seconds.
Releasing the push-button places the unit in SPEED ADJUST MODE.
3. Now press the corresponding pushbutton to
adjust the fresh air fan or the exhaust fan,
thereby changing the air flow. Each press
will reduce motor speed until the default
minimum is reached, at which point the
motor will return to its peak speed.
Allowing a brief pause between presses
(about 0.5 seconds), you will press the
adjust button about 70 times before reaching
minimum speed. During the balancing
procedure, you can switch between
adjusting the fresh air motor or exhaust air
motor.
4. To exit balancing/speed adjust mode, stop pressing buttons for 10 seconds. This will place the
unit back in operating mode with the new speeds saved to the circuit board’s memory.
Low-Speed Adjustment/Balancing. If low speed adjustment is desired, use a jumper wire or remote
control to put the unit into low speed (R—Lo) and follow steps 2-4.

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The equipment recommended for balancing your system is easy to use, reliable and cost
efficient.
Once the HRV system is installed and the vapour barrier is completed, ensure the
following:
Close all windows, doors and fireplace dampers
Turn off any exhaust systems such as dryers, range hoods, bath fans and central
vacuums.
With multiple-speed forced air furnaces in Extended or Simplified systems, the
furnace should operate at continuous low speed.
To balance the HRV, you will need a device to measure air flow. It is recommended to
use either a magnehelic gauge or an air meter, both of which are available from Nu-Air.
Depending on the device you are using, follow one of the two procedures below:
Magnehelic Gauge:
1. Disconnect the flex connector from the rigid duct before any branch ducts and
Compress the flex duct and insert the flow grid. Tape the joint between the flow grid
and ductwork.
2. Set the HRV on high speed. Mount the magnehelic gauge level and plumb. Join the hoses from the
flow grid to the magnehelic gauge. The needle of the magnehelic gauge should read positively.
Switch hose connections if the needle falls below zero.
3. Record reading from gauge and adjust the motor speed to the desired CFM.
4. Repeat the procedure for the next duct. Adjust motor speeds until air flow
readings are equal or within 10% of each other.
Air meter (Nu-Air Part Number 100460):
The 460 air meter is available from Nu-Air wholesalers and can be used to
quickly balance the HRV in less than five minutes.
1. Drill a ¼” hole in both the supply and exhaust ducts on the warm-side of the
machine at least 12” away from the HRV and any elbows, tees, etc.
2. Set the HRV on high speed.
3. Take a pressure reading in each duct and record the results.
4. Go back to the duct having the higher reading, and adjust the airflow down
until the pressure reads to within 10% of the other air flow.
5. Use tape to reseal the holes.
6. To convert pressure readings to airflow (cfm or L/s) refer to the instructions
and table included with the air meter.
4. CONTROLS
Your machine is equipped for remote controls. Options include humidity sensing, off-on control,
intermittent and continuous modes, recirculation as well as high speed control from the dehumidistat or
timer(s). You can also interlock the furnace blower to the HRV. Various means of controlling the
system are described below.

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4.1. Main Board Features
The following sections outline some of these features and explain the board in greater detail. A qualified
technician must do any service work done within the electrical panel of the HRV.
Powerful Transformer
A virtually unlimited number of ES Series controls can be connected in either series or parallel. Up to
six (6) WIN-20 Timers can be connected in parallel.
Circuit Protection
Field mis-wiring of 24 V controls, may cause the board fuse to trip. If this happens, remove the control
wires and allow fuse to reset (may take a few minutes). Check manual for proper wiring connections.
220 V/50 Hz compatibility
Factory adjusted jumper setting for 220V/50Hz geographic areas.
Variable Low- and High-Speed Motor Control
As discussed and illustrated in Section 3, speed adjustment of each motor in both low and high speed is
possible using the FRESH and EXHAUST air pushbutton switches, located on the side of the unit.
12-Volt and 24-Volt Control Options
Because the unit comes complete with a 24 V (up to 10 wires) terminal block and an additional 12 V (4-
wire) receptacle, thus your unit can be operated by a variety of control means and strategies.
Intelligent Defrost Cycles
Your unit will adjust defrost frequency and duration, based on outdoor temperature: -5º C (23º F) -15º C
(5º F), -20º C (-4º F) and -27º C (-17º F).
5th Port, Recirculation and Defrost.
A temperature sensor is located in the fresh air stream before the core. When the outdoor air temperature
is measured at -5º C (23º F), a timed defrost cycle is initiated. For example, at -15º C (5º F) NU145 will
run normally for approximately 37 minutes and then shut off the exhaust air fan for 6 minutes,
meanwhile closing a damper to incoming outside air. Closure of the damper allows the unit to then draw
air from a neutral space through its (top) 5th port and circulate this warm indoor air (not from exhausted
areas) through the heat recovery core to defrost it. Timed cycles repeat until the temperature rises above
- 5º C (23º F). Defrost has priority over all functions, i.e. commands from all remote controls will
start/resume after a defrost cycle.
Neutral Pressure Defrost, Clean Recirculation
In defrost and cycle modes, ES Series H/ERVs do not induce indoor negative pressure nor do they
recycle exhaust air; rather, they redistribute ambient room air. This feature makes your ES Series HRV
ideal for drawing air from super-heated areas, e.g. where a fireplace or woodstove operates, and
distributing this heat to other areas of the home. Consult Section 4.2 for ES recirculation controls.
Backdraft Protection
When the machine is set to Standby, the damper automatically closes off the fresh air port to prevent
the potential of unwanted drafts while the machine is not in operation.

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Selectable Furnace Interlock
The installer may choose between interlock whenever the HRV/ERV is on or only when the HRV/ERV
is operating in high speed (see illustration 10.12).
4.2. ES Series Controls (12 VDC)
Mix and Match Controls. Because the unit circuit board is equipped with
separate, removable terminal blocks to accommodate both ES Series and
Windsor Series controls, both types of control may be used in the same
installation.
All ES Series Controls (sold separately) connect to the 12V (4-wire)
removable terminal block. See Section 10.14 for the wiring diagram
which applies to ALL ES Series controls.
ES Series Mxand Txcontrols are equipped with a touch pad and 3 LED’s. The touch pad is used to
select mode of operation or turn the appliance off. The LED’s indicate which mode of operation the
HRV/ERV is operating in.
ES Series controls can be used in any combination and in virtually any number, and can be wired in
series or in parallel. The user may toggle through and select any function, even if this interrupts a
current mode or cycle.
4.2.1. ES-T1 –20/40/60 Minute Timer
This timer is used to make the unit operate in high speed for 20, 40 or 60 minutes and is typically
installed in bathrooms, kitchens and workspaces. You may toggle between functions or even cancel a
high speed run by tapping the touch pad.
4.2.2. ES-M1 Control
1. No LED: HRV/ERV is OFF
2. Stby: Unit is in standby, ready for a
command
3. Lo: Unit operates in low speed
continuously with high speed
override from timers or sensors.
4. Hi: Unit operates in high speed
continuously
4.2.3. ES-M2 Control
1. No LED: HRV/ERV is OFF
2. Stby: Unit is in standby, ready for a command
3. Lo: Unit operates in low speed continuously
4. 20 Lo/40 Stby: Unit cycles between 20 minutes continuous low and 40 minutes standby.
Selecting operation with ES Controls
is easy: Just tap the touch-pad!

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4.2.4. ES-M3 Control
1. No LED: HRV/ERV is OFF
2. Stby: Unit is in standby, ready for a command
3. Lo: Unit operates in low speed continuously
4. 20 Lo/40 Rec.: Unit cycles between 20 minutes continuous low and 40 minutes recirculation.
4.2.5. ES-M4
1. No LED: HRV/ERV is OFF
2. Stby: Unit is in standby, ready for a command
3. Lo: Unit operates in low speed continuously
4. Rec.: Unit operates in full-time recirculation (Lo) with no outdoor air exchange.
4.2.6. ES-M5
1. No LED: HRV/ERV is OFF
2. Stby: Unit is in standby, ready for a command
3. Lo: Unit operates in low speed continuously
4. Rec.: Unit operates in full-time recirculation (Hi) with no outdoor air exchange.
4.2.7. ES-DVC
The ES-DVC offers a complete package of control options in one control unit.
Features:
LCD Screen
4 touch-sensitive navigation pads
Intuitive user interface
Attractive low-profile case
Bilingual text settings: select English or French in just a few seconds
On-board humidity sensor
5% increment RH bar: accurately read and set relative humidity levels
Built-in timer
90-day runtime filter alert
Programming option for non-recirculation units
Functions:
Off, Standby, Continuous low speed, Continuous high speed, Intermittent high
speed (with humidity call) Continuous recirculation, 20 Lo/40 standby, 20 Lo/40
recirculation, 15-30-45-60-minute timer

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4.3. Windsor Series Controls & Other 24 V Control Options
All Windsor Series and other 24V controls (sold separately) connect to the 24V (10-wire)
removable terminal block. See Section 10 for wiring diagrams.
Mix and Match Controls. Because the unit circuit board is equipped with separate, removable terminal
blocks to accommodate both ES Series and Windsor Series controls, both types of control may be used
in the same installation.
4.3.1. Standard Dehumidistat (Part # DSTAT-1)
With this basic control the system is designed to operate on a low speed for continuous ventilation. The
dehumidistat will switch the HRV to high speed when the relative humidity of the air around it exceeds
its set point. When the indoor humidity falls below the set point, the machine drops out of high speed.
The standard dehumidistat can be complemented with Win-20 timers or ES Series controls. See Section
10.15 for wiring diagram.
4.3.2. Windsor Control (Part # WIN-1)
The Windsor Dehumidistat Control provides the same humidity control as the Standard Dehumidistat,
with the added functionality of a 3-position switch from which the operator can select three operating
modes. See Section 10.16 for wiring diagram.
1. OFF - disables all functions.
2. STANDBY - HRV is on standby (intermittent). High speed ventilation on demand from the
dehumidistat, or remote timers. i.e. Automatically resumes Standby mode after demand is
met.
3. CONTINUOUS - continuous low speed ventilation. HRV cycles to high speed on demand
from the dehumidistat or timers. i.e. Automatically resumes Continuous mode after demand
is met.
Also, the Windsor Control has a two position switch from which you can choose:
Constant - locks the motors in High speed
Standard –normal operating mode enables functions 2 and 3 above.
While it offers several convenient features and operating modes, the Windsor Control can be combined
with the ES –T1 20/40/60 or WIN-20 timer to further customize system functions.
4.3.3. Windsor Timer (WIN-20)
Install in bathrooms, kitchens, workstations or other locations where high-speed ventilation control is
needed. The machine will run at high speed for twenty (20) minutes and then return to its previous
operating condition. Up to six (6) timers can be connected in parallel. See Section 10.17 for wiring
diagram.
4.3.4. Remote On/Off Switching and Spring Wound Timers
Basic RNC control can be achieved using a standard, DEDICATED light switch. Mechanical (spring-
wound) timers, CO2, or occupancy sensors may also be used. See Section 10.18 for wiring diagram.

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4.4. Furnace Interlock
For simplified (return/return) duct systems, it is mandatory that the HRV be interlocked with the furnace
blower such that the furnace fan runs when the HRV is on to distribute supply air throughout the space.
For extended exhaust systems, furnace interlock is recommended. Refer to local building codes.
5. START-UP
Ensure the controls are connected in accordance with Sections 4, 10.
For electrical hook-up, plug into a 120 volt receptacle.
Ensure that the machine is piped to an adequate drainage source, i.e. through the drain hose
supplied.
6. OPERATING HINTS
When a dehumidistat is used, set it at the desired level. Look for signs of excessive humidity or
dryness. Let your windows be your guide.
Winter Operation –40% - 50% is recommended. Lower settings may be necessary in colder
zones to keep windows free of condensation.
Spring/Fall Operation- 50% - 60% is recommended
Summer Operation –For air conditioned homes run the HRV as recommended for winter
operation, i.e. continuous low speed or use a 20/40 setting. In homes without air conditioning,
there is no need to run the HRV during the day when windows are open. If the HRV is connected
to the bathrooms(s) or kitchen, use the standby setting. The normal dehumidistat summer setting
is 65%-80%.
STANDARD FURNACE INTERLOCK
ALTERNATE FURNACE INTERLOCK
If the standard interlocking method has the unwanted effect of bringing on the
AC, i.e. thermostats that do not isolate “G” from “Y”, use the alternate method
shown above.
UNIT 24 VAC REMOVABLE TERMINAL BLOCK
COOLING SYSTEM
FURNACE 24 VAC
NC
I
NO
R
C
TL
TS
SB
Hi
LO
THERMOSTAT TERMINALS
Y
R
G
W
W
G
R
C
Y
UNIT 24 VAC REMOVABLE TERMINAL BLOCK
COOLING SYSTEM
FURNACE 24 VAC
NC
I
NO
R
C
TL
TS
SB
Hi
LO
THERMOSTAT TERMINALS
Y
R
G
W
W
G
R
C
Y

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7. MAINTENANCE
CAUTION: Disconnect power before servicing.
7.5. Filters
Dirty filters can reduce ventilation efficiency, result in unbalanced airflow and damage or shorten the
life of the motors. Vacuum every three months. Polyester filters should typically be replaced every 1-3
years. Permanent electrostatic filters are available from your Nu-Air dealer. Filters remove easily by
opening the front cover.
7.6. Fans
When cleaning the filters, take the opportunity to vacuum any interior surfaces including the fan blades.
No other service is required as these fans are designed to operate continuously without lubrication.
7.7. Condensate Drain
Twice per year wipe clean the condensate drain pan. Check the condensate drain and tubing to ensure
they are free flowing. The tubing must have an "S" or loop that traps a quantity of water to prevent air
from entering the HRV via this tubing.
7.8. Heat/Energy Recovery Core
Polypropylene or aluminum core (located behind the cover) should be removed and cleaned at least once
a year, using a mild detergent in cold water. To remove the cover of the machine, unlatch the two
latches; slide the door to right to release from hinges. Fiber-media core must not be washed, rather
vacuumed at the interval stated above.
7.9. Exterior Hoods
Regularly check the outside vents and clean any obstructions such as
grass, leaves or other debris. Do not replace the screen with mesh
smaller than 1/4" as this will restrict airflow. During winter operation,
ensure snow and frost does not build up and restrict or block openings.
7.10. Grills & Duct Work
Clean the grills when they are dusty or greasy with soap and water.
Check for punctures in the insulation jacket on the fresh air and exhaust
air ducts. Repair any punctures using foil tape.
8. ANNUAL SERVICING:
Your HRV should undergo annual general servicing by an accredited contractor. This servicing should
include the following:
a) The six maintenance items above.
b) A general check for proper operation. Controls and electrical connections should be inspected.
c) Verification that intake and exhaust air flows are properly balanced.
d) Re-balancing as necessary.