PIV & MIV AIR SOURCE
VENTILATION UNIT INSTALLATION GUIDE
AFTER INSTALLATION THE END USER SHOULD KEEP THIS GUIDE FOR FUTURE REFERENCE
DO NOT THROW AWAY
Safety
Read and understand these instructions before beginning installation. The unit should be installed by a competent person.
Location
Check there is space for the unit in your chosen location. The unit must not affect the operation of open-flue appliances. Consult local regulations or a qualified gas engineer. The external vent location in relation to externalflues from appliances e.g. boilers. You must ensure the vent is positioned a minimum of 1 metre horizontally or below a flue and when the supply vent is above a flue.
The open sides of the diffuser must face a minimum 1m unobstructed path away from any smoke detectors. If the diffuser cannot be repositioned, up to two sides can be closed using the plastic blanking plates. In this configuration the open sides must face a minimum 1.5m unobstructed path away from any smoke detectors. If using the 100mm diffusers, no blanking plates are supplied and the diffusers must be repositioned.
In properties with a floor above 4.5m fire diffusers must be fitted a minimum of 1m away from the smoke detectors instead of the included plastic diffusers.
Partition walls between buildings must be complete with any breaks filled.
In properties with a floor more than 4.5m above ground level the unit must be wired into a smoke alarm (see page 16 for wiring information).
The appliance is considered suitable for use in countries with a warm damp equable climate, but may also be used in other countries.
Wiring Regulations
All wiring must comply with Building Regulations and the current IET Wiring Regulations (BS7671 in the UK) or equivalent standards for other countries. The final installation should be examined and tested by a qualified electrician.
This product is not suitable for use with a Type AC RCD
Electrical Connection
The unit must be earthed and a suitable isolator with a minimum contact separation of 3.0mm must be used to provide insulation for the unit.
The unit must be able to be disconnected from the mains supply after installation. When wiring the unit, the included unswitched use spur should be incorporated in the fixed wiring.
The power supply cable running into the unit must remain the supplied flexible cable (not a solid core lighting cable). If the power supply cable becomes damaged, it must be replaced by EnviroVent, an authorised service agent for your region/country, or a similarly qualified person in order to avoid a hazard. Do not remove or tamper with any electronic components inside the product.
Users
The unit is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities or lack of experience and knowledge, unless they have been given supervision and usage instruction by a person responsible for their safety. Children should be supervised to ensure they do not play with the unit. Cleaning and user maintenance must not be performed by children.
Diagrams
PIV AIR SOURCE
MIV AIR SOURCE
INLINE DUCT CONFIGURATIONS
Use one of three options to connect the inline duct to the outside of the property (extra parts not supplied):
- Straight duct to a wall mounted vent or grille.
- Angled duct to a roof tile vent.
- 90 degree bend duct to a straight roof vent.
KEYPAD
- Airflow 1
- Airflow 2
- Airflow 3
- Airflow 4
- Temperature <19 °C
- Temperature >19 °C
- Temperature >25° C
- Top button
- Numeric Display
- Bottom button
WIRING
The local isolator must be connected to the mains as part of the fixed wiring. Connect the N, L and E cores of the power cable to the matching terminals on the local isolator.
PIV Air Source box contents
- 1x PIV Air Source unit
- 1x Loft Filter
- 2x Flexible filter rods
- 1x 150mm Inline filter
- 1x 200mm diffuser (+ 2x blanking plates)
- 1x Instruction guide
- 1x Diffuser mounting template
- 1x Flexible duct (1m x 200mm dia.)
- 1x Unswitched fuse spur
- 1x Remote control (Remote Control units)
- 8x Foam pads
- 4x Washers
- 4x Screws 10g x 3”
- 4x Screws 10g x 1.5”
- 4x Screws 8g x 1.5”
- 4x Screws 8g x 1”
- 4x Plasterboard plugs
- 1x Roll of fixing tape
MIV Air Source box contents
- 1x MIV Air Source unit
- 1x Loft Filter
- 2x Flexible filter rods
- 1x 150mm Inline filter
- 2x 100mm diffusers
- 1x Instruction guide
- 2x Flexible ducts (3m x 100mm dia.)
- 1x Unswitched fuse spur
- 1x Remote control (Remote Control units)
- 8x Foam pads
- 4x Washers
- 4x Screws 10g x 3”
- 4x Screws 10g x 1.5”
- 4x Screws 8g x 1.5”
- 4x Screws 8g x 1”
- 4x Plasterboard plugs
- 4x 100mm duct fixings
- 1x Roll of fixing tape
Pre – Installation Checklist
- Does the unit fit through the loft hatch?
- Check there are no obstructions in the hallway or landing where the diffuser is to be fitted and in the loft space above.
- Ensure the loft has adequate cross-flow ventilation to provide a supply of fresh air to the unit.
- Check that all partition walls are intact. Seek building advice if any are missing or broken.
- Check for flued appliances drawing air from the loft, the user should be made aware of any of these.
- Check that any flue passing through the loft is undamaged. Seek building advice if any are damaged or broken.
- Repair any ceiling gaps which allow air leakage into the loft.
- Ensure any loft water storage tanks are covered and sealed.
About PIV & MIV Air Source units
Positive Input Ventilation (PIV) and Multiple Input Ventilation (MIV) units create fresh and healthy living environments by supplying filtered air into a property at a continuous rate through ceiling mounted diffusers.
The diffusers are normally installed in a hallway or landing area.
The units have been developed to improve indoor air quality and reduce condensation and mould problems.
In conditions between 19°C – 25°C the units will increase air flow rate by 10%. Above 25°C the PIV & MIV airsource units automatically switch to bringing air directly from outside to avoid bringing hot air into the property from the loft space.
The PIV unit uses a single 200mm diffuser to provide air into a hallway or landing area.
The MIV unit uses two 100mm diffusers to provide airflow to separate locations within the building. It is normally required for applications where:
a) The hallway is small.
b) Limited heating is available.
c) The loft hatch fills the hallway ceiling.
d) Airflow is required in a remote area such as a bedroom.
Installation
- Place a dust sheet below the required ceiling diffuser position and check the ceiling below and loft space above are unobstructed.
- a) For PIV units mark a 222mm diffuser hole using the template.
b) For MIV units mark two 105mm diffuser holes (see page 9 for positioning information). - Wearing a dust mask and eye protection, cut out the hole/s.
a) Screw the feet of the unit onto two 25mm x 50mm wood battens using the four 10g x 1.5” screws. (Battens not supplied).
b) Position the unit with anti-vibration pads and washers onto the loft ceiling joists as in the diagram.
c) Screw the unit to the ceiling joists using the four 10g x 3” screws.
d) If the loft insulation sits above the joists and impedes the unit, create a raised wooden platform to mount onto
- Insert the diffuser spigot into the ceiling hole so that the diffuser outlets face towards the walls then mark the four fixing holes.
- Attach the duct to the spigot of the diffuser and seal the connection using the fixings supplied.
- Insert the diffuser spigot into the hole then fix it in place. Use the four plasterboard plugs and four 8g x 1.5”. Then clip the diffuser cover into the diffuser spigot.
- Attach the flexible duct to the spigot on the unit and ensure it is pulled taught. Seal the connection tightly using the fixings supplied. Cut the duct to length if required.
- 9a. INLINE FILTER (all units)
1. Insert the inline filter into a 350mm long section of rigid 150mm diameter duct (not supplied) on the inlet side of the unit.
2. Connect to the filter with a section of flexible duct approximately 300mm long (not supplied).
The connection must be removable, to allow the filter to be replaced. Connect this to an external vent (see page 5 for examples).
9b. LOFT FILTER
1. Insert the two flexible filter rods into the holes in the lid so they cross in the middle.
2. Attach the loft filter over the rods. Line up the Velcro edge on the filter with the matching Velcro edge on the lid and ensure it is attached all the way round. - With the mains supply isolated, wire the power cable into the unswitched fuse spur then wire the unswitched fuse spur into the mains supply (see wiring diagram on page 5). Use two of the 8g x 1” screws to attach the spur to a loft joist.
- The units can be wired to a heater enable switch (not included). Wire into the connection located under the unit (see Page 5, cable not included) and fit it in an accessible area. Do NOT wire into mains or any other power source. Use two of the 8g x 1” screws to attach the switch to the wall
- Reconnect the mains supply at the local isolator. After a few seconds air will begin to flow from the diffuser (see page 16 for air flow rate settings).
Fire Safety
Fire Kits
For installations with a floor more than 4.5m above ground, a compatible fire kit must be fitted. The kits listed below contain all the extra parts and instructions required:
| Order Code | Description |
| KIT-PIV-SMOKE-200 | 200mm fire-rated diffuser for PIV units only |
| KIT-MIV-SMOKE-125 | 2x 125mm fire-rated diffusers for MIV units only |
Smoke Alarms
For installations with a floor more than 4.5m above ground, the unit must be wired into a smoke alarm in order to switch the unit off upon the detection of smoke.
The unit can be wired into an existing smoke alarm (check compatibility with the smoke alarm manufacturer). All wiring should be completed by a competent person.
To test the installation, press the TEST button on top of the smoke alarm and keep it pressed until the PIV unit switches off (LEDs on the board go out).
SMOKE ALARM WIRING
Keypad Settings
Top button
-Press to show the current air flow setting.
-The corresponding LED will illuminate on the keypad.
-Further presses scroll through the air flow rate settings 1,2,3 and 4 on a loop.
-Adjust this according to the size, type and occupancy of the property.
Bottom button
-Press to show the total running time.
-The numeric display will illuminate to show the total amount of time the unit has been running e.g. ‘1234’ (hours).
Wired comfort heater enable/disable
A switch to enable/disable the heater function can be connected up to 3 metres away from the unit. This must be a volt free contact.
Do not wire the cable or switch into the Mains. When the switch is pressed on, the comfort heater function is enabled and the system will maintain the incoming air temperature at 10 °C. When the switch is pressed off, the automatic comfort heater function is disabled.
Running costs
Please scan our QR code to see the annual running costs of this product.
Or visit: envirovent.com/annual-running-costs
Performance Figures – PIV INLINE
| House size setting | Max air flow rate (l/s)a | Power usage (Watts)b |
| 1 | 28 | 2.7 |
| 2 | 38 | 3.8 |
| 3 | 46 | 5.4 |
| 4 | 56 | 8.3 |
Performance Figures – MIV INLINE
| House size setting | Max air flow rate (l/s)a | Power usage (Watts)b |
| 1 | 22 | 3 |
| 2 | 29 | 4 |
| 3 | 35 | 5 |
| 4 | 43 | 8 |
a Diffuser installed without blanking plates fitted.
b Power usage shown with heater function disabled.
c Figures calculated at incoming air temperature below 19 degrees C.
Spares/Accessories
| Item Description | Order Code |
| Replacement coarse particle filter | FILTERMIVAS-COARSE |
| Filter – (PIV/MIV AIR SOURCE, PIV/MIV INLINE) | 1ACFILTASSY150 |
| 200mm diffuser | 1DIFPIV |
| 100mm diffuser | 1DIFEVLSML1 |
| Fixing kit | FIXINGKITEVL-R |
| Heater switch* | HEATER ENABLE SWITCH |
| Smoke alarm** | 1ACSMOKEALARM-KIT |
*Additional two core cable required.
**Additional four core cable required.
Maintenance
EnviroVent recommend that filters are checked regularly and replaced as required. The unit should be isolated from the mains when replacing or cleaning filters.
Areas with high particulate matter for example industrial areas, or higher-grade filters will become clogged quicker and will need replacing more frequently. Spare and replacement filters must be genuine EnviroVent parts.
Failure to maintain the unit as recommended may breach the terms of the warranty. See full warranty terms and conditions for further information.
Warranty
We appreciate you choosing this quality EnviroVent product, which is designed and manufactured to the highest specification in Harrogate, North Yorkshire. We are confident that you will be delighted with the performance of the system and the resulting improvement in air quality in your home after the installation of the unit. This unit is covered by a full 5-year warranty. There is no requirement for maintenance within the first 5 year period other than general cleaning. The warranty covers any defect or break down that arises due to faulty materials or construction. Please note that a receipt will be required as proof of purchase.
Any units bought from an unapproved source, including but not limited to auction websites, are not covered by this warranty.
Your unit serial number
For warranty conditions and exclusions, visit www.envirovent.com/warranty
What should I do if I have a problem?
You should not dismantle or remove any parts of the unit other than those instructed in this guide. Tampering with the unit will void the warranty. For further assistance, please call 01423 810 810.
AFTER COMPLETING INSTALLATION, PASS THIS GUIDE ONTO THE END USER FOR FUTURE REFERENCE
DO NOT THROW AWAY
Leading Manufacturer & Supplier of Innovative & Sustainable Ventilation Systems
E&OE | MKT ENV360 – V12 – 27.02.25
Due to our policy of continuous innovation and improvement EnviroVent reserves the right to alter products specification and appearance without notice.
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EnviroVent Ltd
Harrogate West Business Park
Unit 1 Bardner Bank
Killinghall
Harrogate
HG3 2SP
T / 01423 810 810
E / info@envirovent.com
W / envirovent.com
Boxed unit weight: 9.2kg
Unboxed unit weight: 7.1 kg
Documents / Resources
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envirovent PIV and MIV Air Source Ventilation Unit [pdf] Installation Guide PIV and MIV Air Source Ventilation Unit, MIV Air Source Ventilation Unit, Air Source Ventilation Unit, Ventilation Unit |