If you have worked in the steam industry long enough, you have probably noticed that Amerec generators show up in a lot of commercial specifications and contractor-preferred installations. That is not an accident. The AK Series was purpose-built for residential steam baths with a design philosophy focused on consistent steam quality, easy serviceability, and long-term reliability — qualities that matter a great deal when you are specifying a generator for a client who will use it daily for years.
This review covers every model in the Amerec AK Series — how they work, how they are sized, what makes them different from Mr. Steam and ThermaSol, and which model fits which project.
How the AK Series Works
Every AK generator uses what Amerec calls Sequential Temperature Control. The generator runs at full power to bring the steam room up to its preset temperature quickly, then cuts power by 1/3 or 2/3 of its heating elements to maintain that temperature. The result is a more consistent, softer flow of steam rather than the on/off cycling you get with less sophisticated systems. For the bather, this means a more stable, comfortable experience without dramatic temperature swings.
The tank and water level probes are stainless steel throughout, and the heating elements are removable for easy service — a practical design choice that significantly reduces maintenance cost over the generator's lifespan. All AK Series generators are ETL listed for USA and Canada and tested to IEC standards.
AK Series Model Lineup
The AK Series covers residential steam rooms from 60 to 550 cubic feet across six models. All are available in 240V and 208V, and can be wired in the field for single or three-phase power.
| Model | Room Volume (cu ft) | kW | Amps (240V/1PH) | Breaker |
|---|---|---|---|---|
| AK4.5 | 60–90 | 4.5 | 19 | 30A |
| AK6 | 80–150 | 6 | 25 | 40A |
| AK7.5 | 100–200 | 7.5 | 31 | 40A |
| AK9 | 150–300 | 9 | 38 | 50A |
| AK11 | 200–400 | 11 | 46 | 60A |
| AK14 | 350–550 | 14 | 21 & 38 | 30A & 50A |
Natural stone adjustment: If your steam room walls are natural stone (marble, granite, slate, travertine), multiply your base cubic footage by 1.75 before selecting a model. Stone absorbs significantly more heat than tile. For a full sizing walkthrough, see our steam generator sizing guide, or contact us for a custom spec.
Ganging: What to Do When One Generator Isn't Enough
For steam rooms larger than 550 cubic feet — beyond what a single AK14 can handle — Amerec generators can be ganged together. When ganged, only one generator has a control and temperature sensor connected. Secondary units mimic the primary, so the operation remains as simple as controlling a single generator. Each generator in a ganged setup requires its own auto drain valve, drip pan, and at least one ComfortFlo steamhead.
| Max Room Size (cu ft) | Total kW | Units |
|---|---|---|
| 700 | 18 | AK9 + AK9 |
| 900 | 22 | AK11 + AK11 |
| 1,100 | 28 | AK14 + AK14 |
| 1,300 | 31 | AK11 + AK11 + AK9 |
| 1,500 | 36 | AK14 + AK11 + AK11 |
The Controls: K2, K3, KT3, and K4
Every AK generator is compatible with the full Amerec control lineup — K2, K3, KT3, and K4. One control is required regardless of how many generators are ganged; additional controls can be added.
K2 Touch Screen Control — Amerec's flagship control. Wi-Fi enabled with Google Home and Amazon Alexa compatibility via the SaunaLogic app. Full touchscreen with time, temperature, and light control, 24-hour delay timer, 60-minute session timer, and 6 designer trim finishes. This is the control to specify for smart home integrations.
K3 Touch Screen Control — Same sleek black glass design as the K2 but without app or smart home connectivity. 3-button digital control, mounts inside or outside the steam room, waterproof. Featured in the Columbia Control Package.
KT3 Touch Screen Control — Same as the K3 but with a built-in sensor, requiring installation inside the steam shower rather than outside.
K4 Control — Basic on/off with a 30-minute timer. Control illuminates during operation. Simple, reliable, and the most affordable option.
Note: The Amerec K2 supports both Google Home and Amazon Alexa via the SaunaLogic app — unlike Mr. Steam's iSteamX which supports Alexa only. If a Google Home integration is a requirement, the Amerec K2 is the only residential steam control that delivers it.
Control Packages: The Easy Way to Order
Amerec bundles generators with everything needed for a complete installation into two control packages:
Glacier Control Package — includes K2 control, ComfortFlo SteamHead, ADK Auto Drain, and ADP Drip Pan. Available in 6 finishes.
Columbia Control Package — includes K3 control, ComfortFlo SteamHead, ADK Auto Drain, and ADP Drip Pan. Available in 6 finishes.
Both packages include the ADK Auto Drain — Amerec's automatic drain system that performs recommended daily draining and flushing to reduce mineral scale buildup. For hard water areas this is essential and comes standard in both packages.
How Amerec Compares to Mr. Steam and ThermaSol
Sizing method: Amerec uses a material multiplier (×1.75 for natural stone) with a maximum recommended ceiling height of 8 ft. Mr. Steam uses a more complex system with separate material multipliers and ceiling height factors. ThermaSol is the simplest — no material adjustment, ceiling height handled by moving up model sizes.
Smart home: Amerec K2 supports both Google Home and Alexa. Mr. Steam iSteamX supports Alexa only. ThermaSol does not have native smart home integration.
Steam quality: Amerec's Sequential Temperature Control is a genuine differentiator — the modulated power approach produces a consistently softer steam flow compared to single-speed systems.
Installation: All AK4.5 through AK14 generators share the same shipping box dimensions (22" × 20" × 10.5") and ship at 35 lbs — a practical advantage for tight installation spaces.
Which AK Model Is Right for Your Project?
AK4.5 — compact tile showers 60–90 cu ft. A 4×4×5 ft tile shower is a typical application.
AK6 — tile showers 80–150 cu ft. The most common size for a standard residential steam shower in tile.
AK7.5 — tile showers 100–200 cu ft, or natural stone showers up to ~115 cu ft base volume. A versatile mid-range model.
AK9 — tile showers 150–300 cu ft. The workhorse of the AK Series — covers the majority of generous residential steam showers in tile.
AK11 — tile showers 200–400 cu ft, or large stone showers. Ideal for luxury master bath steam rooms with high ceilings or natural stone.
AK14 — tile showers 350–550 cu ft. The largest single residential AK unit. Requires two ComfortFlo steamheads. For rooms above 550 cu ft, gang two or more AK units.
Why Order from TheSteamStore.com?
- Authorized Amerec Dealer: We carry the full Amerec AK Series including AK7.5, AK11, and AK14 with 208V and 240V options.
- Sizing Help: Contact us for a custom spec.
- Free Shipping: All orders over $199 ship free within the contiguous United States.
Ready to spec an Amerec generator? Browse the full Amerec AK Series at TheSteamStore.com, or contact us directly to confirm the right model for your project.