Saturday, September 6, 2014
Putting in a heated floor
I HATE being cold. I hate the thought of being cold. I hate getting out of bed on a cold winter morning to step on a cold floor. Even carpet can't really take the cold out of a cold floor. The most it can do is attempt to mask the cold and it doesn't do a good job of that.
So I decided to install in floor heating in the bus in an attempt to address that concern. I contacted the kind people at Pex Heating They were very helpful in getting this part of the bus build accomplished. They even designed the heating system for me free. They must have thought it was a joke. I had to submit a design request a couple times before I got a response for a heating system for a 300 square foot school bus. They're used to designing systems for houses and office complexes. So when someone emails a request for a little box of a living space, probably smaller than some of the closets in their other designs, it's understandable if they were skeptical.
They submitted their design and even contacted me by phone to see if I had any questions. Being on a budget I began ordering supplies as monies were available. I have still a few more parts to obtain before the system will be operable but I've gotten the main part, the in-floor tubing down.Here's how that went.
I started by laying down 1/2" foil faced rigid foam insulation.
Next I began laying out the sleeper sub-floor using 1" X 4" furring strips.
The tubing would lay within channels.
I laid out the 1" X 4" strips with spacers to see how the channels would end up.
The videos Pex Heat supplies give very detailed instructions.
You want to make sure you will have a return without having to cross tubing.
Being careful to round the corners where the tubing will turn.
This is the front section of the bus.
They designed the system in two zones. This is the front zone.
I wanted three zones. Their design tech said because of the size of the system I'd only need two.
I'm glad he knew what he was talking about.
This is how the tubing was shipped.
This gives you an idea of how the tubing is constructed.
Getting ready to get to work.
As you lay the tubing down it helps to anchor the turns.
Otherwise if it pulls up you will find yourself short when trying to lay everything back down.
They give very detailed videos on how to install it.
Once down it can be covered.
If you look closely at the picture above you can see the first two rows lifting out of the track. I started with the roll laying on its side and laying the tubing in the track. Then I remembered one of the videos saying the best way to lay the tubing down was to hold the roll feeding it over hand in front of you and walk on it laying it in the track. You're not putting any pressure on the tubing because you are actually walking on the 1" X 4" strips and the tubing is in the grove between them. Once I did this the rest of the tubing laid down with no problem.
Watch the videos on their website.
It was also suggested that if you were to lay a metal transfer plate over the tubing you would get a more even distribution thorough out the entire floor instead of just over the tubes. I had some of the metal ceiling I had taken down left so I used this for the transfer plate. I was mainly concerned with covering the center walking area as the sides will be covered with cabinets and furnishings.
And down goes the top sub floor.
(Above picture) As you start to cover the tubing be sure to mark where the tubing is. Once you cover the tubing it is almost impossible to tell where it is. I drew lines the full length of the bus indicating where the tubing is before I began screwing the top sub-floor down. I would not screw anything within two inches of either side of the lines. If you've done construction work before the norm is to draw lines and screw along the lines. Here I had to remember to screw away from the lines.
Lines drawn. And the screwing begins!
And that was just the front half of the bus.
Now for the back half!
Looking towards the back door.
After the floor is down in goes the pre made closets and walls.
The plan was to finish all this and be operative before I started to travel again. However due to time and financial constraints that hasn't happened. I have the main part installed and will have to finish the rest of the installation as I travel. Stay tuned and I will keep you abreast of how it's going.
There's just short of three hundred feet of tubing running through the floor of the bus. In all I lost 1-3/4" of floor to ceiling height in the bus. 1/2" rigid foam, 3/4" furring strip and 1/2" OSB. That's a small price to pay for warmed floors.
Here is where all the tubing comes up through the floor.
This will be (unlike the European version) my water closet.
It will house all the water controls for the entire bus including a tankless hot water heater.
Check back to see how I'm doing or better yet sign up to get email updates and watch me finish the bus.