The 2nd and most important reason to have a fan in your steam room is to get rid of the thermal barrier (I don't remember the last time I went into a steam room without my fan).
Most people sit in a steam room that is stagnant. It's just still, steam vapor where most of the intense heat is near the ceiling. It's expensive too. Wasted steam. When people sit in a steam room there is a "thermal barrier" of humid air that was warmed by your body heat (not the steam). This heat is from the body's cooling process to transfer heat out of the body. The reason people get so hot and have to get out of the steam room before their session is over is because this thermal layer makes it hard for the body to sweat. This stops the sweating process that the body is trying to cool itself down.
Using a fan creates forced convection. Before fans, we used to do towel waving to bring the heat from the ceiling trap down. The fan will totally blow away the thermal barrier of your skin where it is insulating you. It's an experience most people with steam rooms never experience and it's sad.
When using a fan it increases the sweating since the thermal barrier is removed and heat can transfer from the body to the air. The body can now evaporate and the body's normal cooling process can happen
This allows fresh, slightly cooler air to replace it. This process, called forced convection, significantly increases the rate of heat transfer from your skin, making you feel cooler.
NOTE: IF THE 200 RULE IS BROKEN AND THE ROOM IS WAY OVER 100% HUMIDITY AND THE TEMPERATURE IS OVER 100 DEGREES (This is when the steam is wet and sticky and full of condensate). I wouldn't bother with a fan if the steam quality is this poor. Many people who don't size their generator right and have a cheap low psi generator to start with can have this problem.
Note: When most people are relaxed in a steam room they are not getting the real benefit of heat shock proteins, lipolysis, skin cleansing, full body vasdilation (3 degree artificial fever). If there is not enough HSPs produced from the response to the steam (stress), the benefit of hormesis is not going to happen. When my body is in a 3 degree artificial fever, my body creates enough HSPs to repair and recover from any injuries or sore muscles I have. My body has to be in a vasodilation state for enough time to repair.
Having a fan in the steam room can make even a "sweet spot" temperatur of 110 to 114 degrees feel brutal depending on the fan speed. The temperature stays the same but the stronger the fan is blowing away the insulation layer (thermal barrier) around the skin the hotter it will feel. A 16 inch fan on high will feel way hotter than a 12 inch fan or having the 16 inch fan on medium speed. The faster the speed the faster the steam's latent heat is transferred to the body leading to quicker artificial fever.
Most people just sit on their steam room bench getting little or results they think they are getting. It is borderline uncomfortable to increase the heat transfer from the steam to your skin quicker than it would by just sitting in a stagnant steam room. It takes getting used to for most people. 99% of my customers who decide to get a steam room in their home who have been going to gyms and spas never even heard of disrupting the insulation layer the entire session in their steam room. Once most people use a floor fan to mix thermoclines and a separate fan to get rid of the thermal barrier they don't want to waste time in a steam without it. Kinda cold plunging for the first time, it's not going to be relaxing and comfortable but the benefits outweigh it. Almost anyone will tell you this.
YES, YOU NEED 2 FANS TO GET THE BEST EXPERIENCE. JUST HAVING ONE FAN IS GOOD BUT 2 FANS MAKES IT AN EXCELLENT EXPERIENCE.
Anyone who cares about heat shock proteins and anti-aging should want to get into the habit of whole body steaming with 2 fans. Every time I go to a gym people complain that I bring my fan on the bench. Once I explain how getting rid of their insulatating thermal layer over their skin will help them they thank me instead of what used to happen when I kept to myself and all the sudden the gym manager came in the steam room and told me to remove my fan from the room. It is a waste of time to sit in a steam room with stagnant steam. Forced convection the entire session will change your entire steam room experience.
Floor Fans - I NEVER DO A STEAM SESSION WITHOUT A FAN
I use a floor fan to blow down the hot steam from the ceiling so the entire room is around the same temperature - full body steam therapy. They are ip67 rated and can handle steam. It give the room a high relative humidity and keeps the room at the same temperature the entire session. If you have a ceiling in your steam room over 8 foot high or taller I recommend a fan.
Why have a fan?
First, don't use a fan if you have a steam generator that has less than 95% steam vapor. Condensate does not feel good when blown on me.
If using a fan, know the CFM of the fan (cubic feet per minute). If you have a 250 cubic foot room and a fan that has a CFM of 80, then it won't be strong enough to bring the ceiling thermocline done to give full body vasodilation (full body steam therapy).
With the proper marine grade floor fan, you should no longer have problems with cold spots and hot spots in your steam room.
Having a fan blowing on you is not the same as a a destratification fan that mixes the thermoclines of steam. When the fan blows directly towards the body, this creates a heat co-efficient (opposite of a windchill factor). It makes the steam feel way hotter. When people have a bad back it can help by putting the fan right behind your back or on the side of you blowing on your back. If the steam is too wet it will feel stingy. If the steam is dryer, it will feel amazing.
I love putting low iron oxide Himalayan salt under my steam head. It is so clear it almost looks like quartz.
The more clear the salt is the less iron oxide. I prefer the purist salt I can get.
I don't use this type for my steam room.
At the gym, I always go in before my workout and an hour later the salt is hot and ready to give off ions. You can take an Ion Meter to measure the ions in the steam room before and after. I bought mine on Ebay for about 30 bucks.
pic of green pic on 200 rule page on biohack sauna
Note: when the body can't sweat due to the thermal barrier (without using a fan) water soluble toxins can have a hard time being released from the skin. The pores are being blocked by the insulation layer if the fan is not blowing this layer away.
Note: if I can stay in the steam room more than 15 at a time then the relative humidity is too low. Anyone using a steam room in their home unlike a gym where you can't control the temperature and humidity as much I believe should have an understanding between humidity and temperature. (At least understand the '200 Rule".
If the steam room is at 115 degrees, I want to make sure the humidity is no more than 85% (115 +85 = 200).
Many people like what is referred to as a "Bio Steamroom". This is when the temperature is much lower and the humidity is high.
Know your attitude towards your steam room. There are 2 types of attitudes you can have when going in the steam room: Are you the type that wants to relax and enjoy the steam and just chill out? You aren’t concerned about health benefits even though you know you are getting them. The other way to view your steam room is as a workout or detox tool. You are trying to biohack and maximize the benefits of the steam the best you can. Many people don’t like being borderline uncomfortable during their steamroom session. Most people don’t have the discipline.
