Sauna owners, How long to heat up your sauna

[Masquernom]

The name eludes me, but there was a company in the US that made a triple pane window where the middle pane was a plastic film. Works like triple pane glass, but the window is much lighter. You'd have to search for them.

Much better insulation than just double pane glass windows. Since you won't be opening the window, triple glass is probably fine though.

 

[Out-to-Lunch]

Very nice, Out-To-Lunch, thanks for the photos!

We have a family cabin in a far northern climate that we will either completely redo or build a new cabin on the property and use the old one as a guest house, and I've been imagining putting in a sauna there once we're retired and use it more.

Bruceski44's comment about watching TV through the window has me wondering...even the best glass is still less efficient than a properly constructed wall, right? I was wondering about having a big window to either watch a big TV or look out at the lake. No neighbors visible, I'm not worried about being seen, so I'm wondering about a really big window, but I'm guessing that's probably going to lose a lot of heat, no matter how much I spend on special glass/glass treatment?

I have been in (commercial) saunas with huge glass windows. It is a real treat.

Some rough calculation and googling tells me that a triple pane window will have about 1/4 of the R-value of a 3.5" fiberglass batt. (3.2 for the window vs. 11.7 for the batt. Of course, the wood cladding would also add some.) If you want, I could figure out how many watts we are talking about in each case. (If so, guesstimate a window size.)

 

[sengsational]

I built a sauna as a covid project. Started in the spring and finished in the summer. I bought a timer so that you could have it start to heat up at some point in the future. That would be good if you knew you were out hiking or something for X hours and wanted to jump right in when you got back, but I've only used the timer once. Mine is hot in about 30 minutes. It's the smallest size possible (4x4) and the heater I got is 220 and it can be used in considerably larger saunas, so it's pretty quick to heat up the room.

I made a few youtube videos about my project. The first one was primarily about how I carved out the space from the crawl space area adjacent to my basement, but includes my shopping process. The other one is about assembling the kit. Warning: These videos are very long and boring!

 

[The Cosmic Avenger]

I have been in (commercial) saunas with huge glass windows. It is a real treat.

Some rough calculation and googling tells me that a triple pane window will have about 1/4 of the R-value of a 3.5" fiberglass batt. (3.2 for the window vs. 11.7 for the batt. Of course, the wood cladding would also add some.) If you want, I could figure out how many watts we are talking about in each case. (If so, guesstimate a window size.)

That's the kind of ballpark I was looking for, thanks! That sounds pretty significant, so a significant window would have a huge impact on heat loss, no matter the materials.

Of course, if you are bored, I was imagining a large picture window, large enough to watch a huge TV through or see the lake in much of your field of vision if you were fairly close, maybe 72" by 42"?

Maybe I should consider a glass door, which would be expensive, but I could add a more insulated door that I could close if I wanted to save energy and didn't need the view. Or shutters, I wonder if that would work?

Thanks, this is a great exercise, I'll make a note to refer back to this post when I eventually ask around about estimates!

 

[Time2]

Sengsational 1, has me questioning my size. I was going for 4 x 7 or possibly 4 x 6, that is because I thought I would want to be able to lay down. I would reduce it just so it wouldn't take as much space where I plan to put it and to reduce the cost. It will probably be only me, I'm not sure it is something I could get my wife to do.



How many people actually lay down in their sauna?

 

[Masquernom]

Found some info on sauna glass;

https://www.saunatimes.com/building...ws-in-the-sauna-i-can-really-see-clearly-now/

 

[Out-to-Lunch]

That's the kind of ballpark I was looking for, thanks! That sounds pretty significant, so a significant window would have a huge impact on heat loss, no matter the materials.

Of course, if you are bored, I was imagining a large picture window, large enough to watch a huge TV through or see the lake in much of your field of vision if you were fairly close, maybe 72" by 42"?

Maybe I should consider a glass door, which would be expensive, but I could add a more insulated door that I could close if I wanted to save energy and didn't need the view. Or shutters, I wonder if that would work?

Thanks, this is a great exercise, I'll make a note to refer back to this post when I eventually ask around about estimates!

It is easier to make the calculation in metric. I assumed a temperature difference of (170 F - 32 F) = 138 F (or 77 C). That window is about ~2 m^2. Taking account of the different definition of R-value with metric units, I find a heat loss through the window of about 270 Watts. A fiberglass batt would pass about 75 W. (I took no account of the wood cladding or possible thermal bridging.)

Not sure how I feel about that. 270 W is not small, but may not really be a dealbreaker. If you pay $0.20 per kW-hour, that is about a nickel per hour.

 

[Music Lover]

Not sure how I feel about that. 270 W is not small, but may not really be a dealbreaker. If you pay $0.20 per kW-hour, that is about a nickel per hour.

5 cents an hour to gain a view. It it's used 3 or 4 hours a week and that's not even $1 a month. Even if there's no view a window is an improvement over feeling enclosed in a small box.

 

[Out-to-Lunch]

How many people actually lay down in their sauna?

My wife usually does. I sometimes do, but not always. Usually I sit with my heels up on the same bench that I am sitting on. (This is why the wider bench is so important.)

 

[Out-to-Lunch]

Found some info on sauna glass;

https://www.saunatimes.com/building...ws-in-the-sauna-i-can-really-see-clearly-now/

This is exactly what I did. Worked like a charm.

 

[Bruceski44]

How many people actually lay down in their sauna?

I like to elevate my legs after cycling but my sauna's too small to lie down in. I can lie on my back with my legs going up the wall, but it's very hard to get in and out of that position, and uncomfortable to be in for very long. I can sit crosswise on the two-person bench with my back upright and legs bent with feet on the opposite wall, but it doesn't have the same effect and is still uncomfortable.

 

[cyber888]

What does it cost to build a sauna from scratch? Or is it better to buy a prepackaged one? I would like to add one to the master bathroom to replace the tub we never use.

Mine cost $200 or less

 

[Time2]

I'm getting ideas together to build a sauna. I have concerns that if we ever move or I end up not using the sauna, I would not be able to remove it from the area where I build it. In case I want to take on a move or sell it. So I was looking at prefab units to see how I could build it so it will come apart. Each part would have to go through a normal doorway. I found this website showing assembly of prefab sections. I got some great ideas from it.
https://www.youtube.com/channel/UCG9VZ8OELBJrhNW21ZNHcdQ

 

[db79]

My 3 person IR sauna takes approx. 20 minutes to get up to temp.

 

[zinger1457]

Have you looked at these types of pre-fabed units? Takes maybe 3-4 hours to completely assemble or take apart.
https://www.jnhlifestyles.com/all-saunas/

 

[sengsational]

My wife usually does. I sometimes do, but not always. Usually I sit with my heels up on the same bench that I am sitting on. (This is why the wider bench is so important.)

Mine is too small to lay down. Always have my feet on the same level that I'm sitting at, and it's very comfortable. Having a chair-style position is possible, not as comfortable. The kit included a leaner thing, and with scraps, I built a second one.

 

[Out-to-Lunch]

Mine is too small to lay down. Always have my feet on the same level that I'm sitting at, and it's very comfortable. Having a chair-style position is possible, not as comfortable. The kit included a leaner thing, and with scraps, I built a second one.

Looks good! I usually just lean against the wall, but your leaner looks comfy.

 

[Music Lover]

My GF has a small kit sauna 42" x 42". I've moved it 3 times in the last 3 years...to take it apart and set up again takes less than a half hour.

Kits are a good choice if you want to move it at some point. Also, a sauna that size can fit in the corner of bedroom or in a tight location.

 

[ut2sua]

That is true. Mine tops out at 150°F but I can develop nearly as much sweat in it as a regular sauna. I just have to stay in a little longer.

The difference, as usually explained, is that a regular sauna heats the air, which in turn heats the body. An IR sauna's radiation goes directly into you, the same as sitting outdoors in the sun, so the lower air temperature is less relevant.

+1
I have had my unit for a few years and have enjoyed using it.
A lot less energy is used for the IR panels so your electrical bill is not going up much. The stand-alone unit is easy to set up and cost around ~1K