My Experience with the Envi Heater

Marc Bilodeau/ Product Reviews, Tiny House

I considered using the Envi Heater as a primary heat source when plans for the tiny house were coming together. In the end, I decided to go with a wall mountable HVAC unit as a primary heat source. Thankfully, it has been running quite well over the past year. However, I have an Envi Heater in the tiny house as a secondary heat source. During my research on possible heating and cooling solutions, I discovered that many people use the Envi Heater for their tiny houses and extra rooms.

I did some experimentation with the Envi Heater when the tiny house was just over half done. Although, that experiment was somewhat flawed because the tiny house still needed a little bit more insulation work. Now that the tiny house is 95% complete, it is a good time to revisit this experiment.

Installing the Envi Heater

This heater is very easy to install. The packaging contains the heater and a template to help align the unit properly on the wall. Other than a couple of tools, the heater comes with everything you need to install it. Two screws hold the tabs that lock the heater in place. Fortunately, it is difficult to install the heater incorrectly because it won’t turn on until the tabs are in the proper slots behind the heater.

The Envi Heater has two different options to power the unit. One is to plug the unit into an outlet, and the other is to hardwire it into the wall. I have a unit with a standard electrical cord. Regardless, the installation takes no time at all. This heater is the perfect size for a tiny house or a small room since it takes up very little space.

Envi Heater as Advertised

At 475 watts, this unit requires less power than other heating solution. Furthermore, this low watt convection heating doesn’t dry out the air thereby decreasing the humidity.

My roughly 180 square-foot (~16.7 square-meter) tiny house is slightly larger than the room sizes the unit is designed to heat. However, the heater is powerful enough to heat a 130 to 150 square-foot (~12.1 to ~14 square-meter) room.

An analog dial controls the temperature. At the maximum setting, the temperature of the air from the unit is about 190F (~88C). The unit is silent while it is running. Thankfully, there is a red light above the power switch to indicate that the unit is on.

The Conditions of the Experiment

As with any experiment, I set some conditions to properly compare the results against the capabilities of the Envi Heater. The experiment started on Wednesday afternoon on March 27th and ended about the same time on April 10th.

First, everything in the tiny house is off except the ceiling fan, Google Home, smart plugs, neurio sensor, temperature sensors, and the magic mirror. The ceiling fan is continuously circulating air around the tiny house.

Secondly, the Envi Heater is set to its maximum temperature. This will show how well the heater works when the outside temperature changes over the entire two weeks. Ideally, someone would keep the dial at a level so the heater would turn on and off to maintain the temperature. However, I am using the heater as a secondary heat source, and the heater is plugged into a smart plug. Therefore, I keep the heater at its highest setting. Then, I can use voice commands to turn the heater on and off as needed.

Lastly, the tiny house is empty. No one is living in the tiny house, nor are there blinds in the windows to help deflect the outside cold.

How Did the Envi Heater Do?

Outside Conditions

First, the outside conditions changed quite a bit over the two weeks. The wind was calm (4 mph / ~6 kph) to very windy (30 mph / ~48 kph). Temperatures fluctuated between 24F (~-4.4C ) and 61F (~16C). Furthermore, several nights and days were just above or below freezing (32F / 0C).

Inside Temperatures

With the outside temperature swaying over a wide range, the inside temperatures range was 61F (~16C) to 83F (~28C). As a reminder, the Envi Heater remained on the whole time. Therefore, it would remain running regardless of the inside temperature. Ideally, the dial would be set appropriately, and then turn off when the temperature reached a certain point.

Overall, the inside temperatures stayed in the low to mid 60s (~15.5C to ~18.3C) when the outside temperatures dipped below 32F (0C). Conversely, the temperature easily climbed above 80F (~27C) when the outside temperature reached 60F (15.5C). However, if the outside temperature stayed between 40F (~4.4C) to 45F (~7C), the Envi Heater has no issues keeping the tiny house around a comfortable 70F (~21C) temperature. This means the Envi Heater could be ideal for climates with milder winters.

Power Usage

The Envi Heater touts a low power usage of roughly 475W. During the two weeks, the power usage fluctuated between 490W and 580W. However, there are a few caveats.

First, the spike between March 29 and March 30 is when the ceiling fan was turned on. This also shows up as a brief drop of the inside temperature around the same time.

Secondly, between April 1 and April 2 the power usage was higher. I accidentally told my Google Home to turn on the great room lights (the home automation is still a work in progress).

Lastly, there is 61W in use because of the sensors, smart switches, magic mirror, neurio, ceiling fan, Google Home, and smart outlets. If I remove from the data that usage and the other two caveats mentioned above, the Envi Heater used between 460W and 520W. This is both above and below the advertised 475W. Certainly a factor for those planning a solar, wind, or hydro-based electrical system. Regardless, this is much lower than other heating systems. For comparison, a small desk size space heater (which isn’t designed for an entire room) can easily use 1500W. This makes the Envi Heater quite impressive related to power usage.


It does get a lot colder in Maine. In fact, I may re-run this experiment next winter when the temperatures are in the single digits and below zero. However, the range of temperatures during this two week time frame show enough variation to see how well the Envi Heater performs when temperatures range from below freezing to 60F (~15C). Overall, I like the Envi Heater and would recommend it to anyone. I believe it will do well to heat the tiny house in any morning or night from mid-spring to late fall.

In summary, the Envi Heater is a great product. It will work well as a secondary heat source in the tiny house. In fact, it may do well as the primary heat source for climates with winters that average in the upper 30Fs to low 40Fs (~3C to ~6C). It’s quiet, compact, and uses less energy than most heating units.

Click here to learn more about the Envi Heater. Click here for a great video review.