Telaire Ventostat T8100-R / T8200-R

At a glance

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

• Worth knowing: 800 out of the box; lower not published
• Plain fact: Ships switching at 800 ppm, with a 100 ppm gapIts switches choose 800, 1,000, 1,200 or 1,500. 800 is at the goal, not under it.
• Not stated by the maker: Custom settings need Telaire’s T2090 softwareTelaire doesn’t publish the range it allows. Ask whether it can be set to 750.
• Worth knowing: Turn its self-calibration off for a bedroomTelaire says it should be off in rooms occupied around the clock; the T2090 software switches it.
• Worth knowing: Get an -R modelThe plain T8100 has no relay.

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 Telaire whether its T2090 software allows a 750 ppm setting. If it does, set it there.
2. If not, 800 is its lowest switch setting: the room will sit near 800 for much of the night, so pair it with a night schedule and check your nights.
3. Turn self-calibration off with the same software.

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

Any ventilator with a low-voltage input that holds high speed while two terminals are joined. Ventilator makers don’t name third-party controls: check your unit’s manual and ask your installer first.

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

Specs

Contacts

Normally open and normally closed, 0.5 A at 125 V AC, 1 A at 24 V DC

Gap

100 ppm at every setting

Power

18–30 V AC or 18–42 V DC, 0.7 W

Mounting

Wall

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

Wall CO₂ controllers with a relay

A sensor that closes a switch above its setting. Wired to a unit’s high-speed input, it runs the unit on high until CO₂ drops. Commercial products; an installer fits them.

• 

  Greystone CD2RMC

  Setting range not published

  Room CO₂ transmitter, optional relay

• Greystone CDD4A

  Can be set under 800

  Room CO₂ controller with a programmable relay

• Kele CD-AW

  Can be set under 800

  Wall CO₂ controller with a dry contact