How Mirror Defoggers Work and When to Specify Them
How an anti-fog defogger keeps a bathroom mirror clear, which bathrooms need one, and what the defogger adds to the electrical specification.
A fogged mirror is a small problem that generates a large number of complaints, because it happens to every guest, every morning, in exactly the bathrooms that were built to be efficient and compact.
Why Mirrors Fog
Condensation forms when warm humid air meets a surface below the dew point. A mirror on an outside wall in a compact bathroom is usually the coldest surface in the room, so it fogs first and clears last.
The guest response is to wipe it with a towel, which works once and gradually marks the surface over the life of the mirror.
What a Defogger Does
A heated pad is bonded behind the mirror. It holds the glass above the dew point while it is powered, so the surface never fogs rather than clearing afterwards.
Our HQ004 fog free model has the defogger fitted as standard, and anti-fog is available as an option across the frameless, framed and lit cabinet ranges.
Which Bathrooms Need One
Compact bathrooms where the shower is close to the vanity, wet rooms, bathrooms with limited extract ventilation, and any property in a humid climate such as the Miami market.
In a well ventilated bathroom with a separate shower room, a defogger is optional rather than necessary.
What It Adds to the Specification
The defogger is a separate heated element, so it has to be accounted for on the circuit before first fix. It can be switched with the mirror light or separately, depending on your specification.
The clear zone follows the pad, so tell us the mirror size and the area you want kept clear and the pad is sized to it.
Key Points
- A defogger keeps the glass above the dew point rather than clearing it later
- HQ004 has one fitted as standard; it is optional across the rest of the range
- Specify one for compact, poorly ventilated or humid bathrooms
- Account for the heated element on the circuit before first fix
Models This Guide Refers To
Fog Free Bathroom LED Mirror Model HQ004
HQ004 is the fog free model. A heated pad behind the glass keeps the mirror surface above the dew point, so the guest has a clear mi...
View Model Details
Lit Medicine Cabinet
A mirrored LED cabinet that replaces the mirror and the storage in one opening. Increasingly the default in North American bathrooms...
View Model DetailsWhere This Came Up in Practice
Questions About This Guide
Who is how mirror defoggers work and when to specify them written for?
Project teams, specifiers and buyers who have to make a decision about a lighted mirror rather than browse a catalogue.
Can you supply a specification sheet on this subject?
Yes. Email us the model name and we will send the specification sheet.
Does this apply to lit medicine cabinets as well as mirrors?
Unless the guide says otherwise, yes. The cabinets share the mirror, lighting and electrical specification.
Who do I contact with a follow up question?
Email [email protected] with the project details and the question.
Need This Checked Against Your Project
Send the drawing, the sizes and the functions you are considering and we will tell you what we would specify.