Water vapour, or mist, fireplaces are among the most realistic electric fireplaces available. That’s because the mist creates the effect of a live flame, with a physical presence that reacts to air movement the way a real flame would. To create the mist, regular tap water is ultrasonically vibrated into tiny droplets by a transducer inside the water reservoir. The most well-known of the water vapour fireplaces is Dimplex Optimyst, which was introduced over a decade ago. While it’s not new technology, there have been many updates over time, to get to the water-based electric fireplaces that we enjoy today. Optimyst now comes in several variations, with different features and benefits for your design projects. Below is our comparison of the various Dimplex water vapour fireplaces.

Dimplex Optimyst CDFI cassettes – CDFI500-PRO, CDFI1000-PRO

Optimyst cassettes are an update on the very first Dimplex Optimyst fireplaces. They are essentially a metal box that holds a water reservoir. Inside the reservoir, an ultrasonic transducer turns the water into mist. That mist is then pushed out through a slot in the metal top, or through gaps in the optional log kits. When the mist is hit with warm yellow light from below, it gives the illusion of live flames. This is an open-flame effect; there is no glass. However, they are perfectly safe because the ‘flames’ won’t burn. Cassettes are the only Optimyst format for which you may refill the water reservoir manually, by removing the top and filling the interior water bottle. However, we strongly recommend connecting a plumbing line if you plan to use your fireplace frequently. Optimyst cassettes have some great advantages for fireplace designers:

• Optimyst cassettes are modular – they can be used in combination to create larger fireplaces. Cassettes come in 20-inch and 40-inch lengths, which may be installed side by side to create fireplaces that are 60, 80, 100, or 120 inches long, or longer. These are ideal for large commercial installations where a safe but impressive fireplace is desired. We have seen great examples of these larger fireplaces in condo lobbies and party rooms.
• Optimyst cassettes are customizable – they can be installed into any structure that you can dream up to contain them. Because they are zero-clearance and are not producing live flames, your surrounding materials do not need to be fire-proof. There are some guidelines for the distances between the burner and the wall materials, to avoid condensation; otherwise, the sky’s the limit. They may be built into a niche, only open on the front, or they can be left open all the way around, or closed on any number of sides. This is the ultimate designer fireplace.
• Optimyst cassettes have optional heating – you only install the heater if you want it. For commercial installations in particular, this is a benefit. There’s no need to worry about someone turning on a heater when it’s not needed, because you can choose not to add one. Of course, if you have the heater installed, you can choose whether or not to turn it on, which is a huge benefit for homeowners.

Pro Tip: In order to push the mist out the top, Optimyst Cassettes need to pull air in from below the cassette. This air intake must be incorporated into your wall design and cannot be ignored. It is spelled out in the owner’s manual, with minimum air intake requirements.

Dimplex Optimyst built-in firebox with CDFI Cassettes – GBF1000-PRO, GBF1500-PRO

Dimplex GBF units incorporate CDFI cassettes into a metal casing that incorporates a heater and front glass; optional rear glass may be added for a see-through fireplace. There are 2 sizes, a 40-inch and a 60-inch width. The main advantage of the GBF units is that they bring all of the Optimyst elements together in a format that allows for them to be built into the wall like any other electric fireplace. This simplifies installation, although the requirement for air intake is still valid. Because the GBF units incorporate CDFI cassettes, the water reservoirs could be refilled manually. However, removing the glass is tedious and you risk breaking it. For this reason, we strongly recommend that you install a plumbing line.

Pro Tip: To minimize fog build-up on the front glass, we recommend cleaning the glass with a defogging cleaner (much like you would with ski goggles). This extends the length of time between cleaning.

Dimplex Optimyst Linear fireplace – OLF46-AM, OLF66-AM, OLF86-AM

After more than a decade of experience with Optimyst cassettes, Dimplex finally introduced an Optimyst fireplace that incorporates all of the features that designers and homeowners love about regular LED electric fireplaces. OLF models are linear, which is the best-selling style of fireplace at this time. They are also just under 12-inches, which is a growing subcategory for electric fireplaces. They were able to slim down these built-in fireplaces by integrating the reservoir into the firebox, and not relying on the cassette system. Dimplex has also updated some other features of their Optimyst cassettes and GBF fireplaces with the OLF models:

• Flame colours – Optimyst linear fireplaces have changeable flame colours and accent lighting; cassettes and GBF fireplaces have just natural yellow flames.
• Foggy glass – At start-up, an OLF unit uses the internal heater to warm up the glass for 3 minutes, so that the mist will not cause the glass to fog. There is also a ‘defog’ feature to clear the glass should it fog up during operation. These features don’t exist on the GBF units, so foggy glass results during most start-ups, especially in winter.
• Thermostat control – OLF models have a more robust heater than past Optimyst fireplaces, with thermostat control. Past Optimyst heaters where on-off only, and did not have as much heating capacity as the new OLF heaters.

Coming Soon! Amantii Signature with Optimyst

In a unique collaboration between rival manufacturers, Amantii has unveiled their new Signature series, which combines their own traditional insert with an Optimyst burner from Dimplex. It will be rolled out in a 38-inch size in the latter half of 2024. As Dimplex doesn’t make any of their own traditional inserts with Optimyst, it’s refreshing to see the new introduction from Amantii. The Signature with Optimyst will have multi-coloured flames, a choice of interior side panels, and Amantii’s full range of media packages to choose from. You can get a sneak peek at it in this video. Watch the Amantii shop on our website for details as soon as it becomes available.

Stylish Fireplaces knows that adding a fireplace to your home can be challenging. With an electric fireplace and their NFI Certified Hearth Design Specialists, it’s easy to create a space you’ll love to share with family and friends. Check out all the options and connect with their experts for help to find the perfect electric fireplace for you. You’ll live stylishly ever after.