Fantech CO2RT-R (item 99315)

At a glance

• In its favour
• Plain fact
• Worth knowing
• Not stated by the maker

• Not stated by the maker: Setting range not published
• Plain fact: Switches the unit to high speed above its set pointA relay with normally open and normally closed contacts.
• Not stated by the maker: Its set-point range and factory setting aren’t publishedSo we can’t confirm it can be set to 750. Ask Fantech before buying.
• Worth knowing: Fantech doesn’t show it wired to a home unitIt’s sold with commercial units, “for a single area such as a conference room”. Fantech’s 2022 product card for the HERO 200H lists it as an accessory, but no Fantech document shows the wiring.
• Worth knowing: Self-calibrates, with no off switch documentedIn a bedroom that never airs out, that can pull its readings low.
• Worth knowing: Regin lists it as discontinued

Regin, its maker, lists it as discontinued.

Setting it for a bedroom

HouseExhale’s setting: switch up at 750 ppm and back at 650, or ramp from 600 to full by 750. Never above 800.

1. Ask Fantech for its set-point range first. If it can be set to 750 ppm, set it there; if it can’t go below 800, it won’t meet the goal.

A Danish study ran a bedroom fan from about 900 ppm and the nights still averaged 835, so a control has to start below the goal. Good home CO₂ sensors are rated within about 55 to 90 ppm at 800, and the night average includes the climb after bedtime, so 750 on and 650 off leaves room for both. A control in the return duct mixes the bedroom with empty rooms, so it needs lower settings still (about 650 on, 550 off), and your monitor in the bedroom has the final word. These are HouseExhale’s numbers: no study has tested a control against an 800 night average yet.

What it works with

Its maker’s own units, as its manual says.

• 

  Fantech HERO 200H

  Listed as an accessory; wiring not documented

  195 cfm at 0.5 in.

How to add CO₂ control to an HRV or ERV · HRV and ERV units

Specs

Sensor

True CO₂ (NDIR), 0–2,000 ppm

Relay

50 V AC or 60 V DC, 1 A; terminals 3 (common), 4 (normally open), 5 (normally closed)

Power

24 V AC, or 15–35 V DC (3 W)

Mounting

Wall or wall box

From the maker’s documents, read October 17, 2026. Prices are before tax and shipping and change often.

Made by the ventilator’s maker

Sold for a maker’s own units, with the wiring in its manuals. An installer fits them.

• 

  RenewAire CO2-W (wall) and CO2-D (duct)

  Can be set under 800

  CO₂ controller with a relay, for RenewAire ERVs

• S&P SCO2-W

  Can be set under 800

  Wall CO₂ control for S&P ventilators

• 

  Zehnder CO₂ sensor (0–10 V) with the Option Box

  Can be set under 800

  Wall CO₂ sensor for ComfoAir units