In-floor heat

[custom1]

Re: Infloor heat

Of my outside measurement is 24x24 my wall is 6-1/2 thick I came another 2ft in with my out most loop so Im not wasting my heat to the outside so technically I heading 240.25sqft of slab. Im not looking for it to heat things to 90 Im looking for anything above 32.

I was told that the pex should be 1ft apart with that said if I added any extra to my floor it would be over lapping .

scrapart, I think you might have more than 150' of pex in the floor. Also I think your math is a little off. The inside of your space is about 23x23 and if you came in 2' from that your outer loop is 19x19 which is 361 sqft. not 240. Are you saying you kept the pex 1' apart? If so you have to have more than 150 in there. Unless I misread your post.

The other thing you are going to have trouble with is fluid speed. With just one loop the speed will be faster than if you had two or three loops to divide up the flow. The faster the fluid is moving the less time the floor has to absorb the heat out of it.

I'm not saying it wont work. It's just another thing to think about.

 

[Fastback]

If thats the case then slow it down somehow. You could get creative with a tiny 1/40th hp circulator or even restriction/flow adjusters.

 

[scrapart]

Its been a little bit I lost my Internet . I found out I do have 200' of pex in my floor. I have not done much with my setup I have yet to get the tank and valve . So Im building an addition on to my garage its going 17x10 and I can with some effort get to the out most loop of my pex on the side where my addition is going . My question it would it be fesable to cut the pex and add line to the floor of my addition? I also have access to 9 cast iron radiators that use to be in an older building could I sue these in my system?

 

[scrapart]

Re: Infloor heat

scrapart, I think you might have more than 150' of pex in the floor. Also I think your math is a little off. The inside of your space is about 23x23 and if you came in 2' from that your outer loop is 19x19 which is 361 sqft. not 240. Are you saying you kept the pex 1' apart? If so you have to have more than 150 in there. Unless I misread your post.

The other thing you are going to have trouble with is fluid speed. With just one loop the speed will be faster than if you had two or three loops to divide up the flow. The faster the fluid is moving the less time the floor has to absorb the heat out of it.

I'm not saying it wont work. It's just another thing to think about.

How could it be 23x23 when the outside is 24x24 and my walls are 6.5"thick forgot to include the osb that puts my inside at 17.5x17.5 .

 

[jlckmj]

How could it be 23x23 when the outside is 24x24 and my walls are 6.5"thick forgot to include the osb that puts my inside at 17.5x17.5 .

? ? ?

 

[scrapart]

Read what custom1 is saying then you'll understand

 

[custom1]

Scrap, I agree with jlckmj.....????

If you subtract 6.5 inches from both sides of a 24 foot wall you end up with a wall "about" 23 feet long. Actually exactly 22 feet 11 inches. You seem to be subtracting 6.5 feet from the 24 feet length.

So then when you move in 2 feet on each end from the 23 foot wall your pex outer loop is 19 x 19 which is 361 sq ft. The slab itself is still 23x23 which is 529 sq ft.

You don't want to ad pex to the outer loop. I think you will be over the 300 feet total length ballpark that most people recommend. You would be better off with a manifold and a second loop just for the new part. This would also solve the fluid speed problem and both loops would work better at getting the heat into the slabs. The loops need to all be the same length or close to it to be balanced.

 

[scrapart]

See picture on my thinking of the size.

 

[anthony666]

6.5 inches, not 6.5 feet

times 2 walls = 13 inches .. 24 feet minus 13 inches = 22'11"

 

[scrapart]

So how do I manage to get the tube from the addition to the heater ?

 

[scrapart]

I was like where did he get ft opps I see...

 

[anthony666]

I was like where did he get ft opps I see...

only my wife is perfect, i know because she tells me often

 

[anthony666]

So how do I manage to get the tube from the addition to the heater ?

run a line set of 1/2" out to the addition .. run two loops off that of about 80 or 90 feet each .. trust me, it will work

 

[scrapart]

only my wife is perfect, i know because she tells me often

So is my wife

 

[scrapart]

run a line set of 1/2" out to the addition .. run two loops off that of about 80 or 90 feet each .. trust me, it will work

So it will be ok just to have the line running along the floor it wont lose to much heat? Once I get it out to the add I have two in lines and two lines out. will I need another pump?

 

[anthony666]

So it will be ok just to have the line running along the floor it wont lose to much heat? Once I get it out to the add I have two in lines and two lines out. will I need another pump?

i dunno what you have in place already .. if nothing is yet built just run the line set off manifold for the main area .. put armaflex on the line set if you're gonna bury it in the floor .. burying it in the floor keeps things neat and well protected

if you want separate control over the addition you're gonna either have to use a zone valve or actuator, or pipe that on it's own with a dedicated pump

 

[scrapart]

Ok I have not started on my addition yet but Im collecting all my parts and pieces. In my garage I have the heater pump and pex I have yet to add the tank and air valve. To control the heat couldn't I have a low line voltage T-stat out in the addition where I want the main heat to be?

 

[scrapart]

Well I guess the help went dead. Thanks

 

[anthony666]

sorry scrap .. missed it while trying to make a living

tough to make out your diagram, try drawing it out again .. but from what i can see i would say no it won't work .. water will only flow the easiest way possible unless it's forced to flow by pumps you need to manifold the lines going into the floor and the line set going to the addition and set it up in reverse return .. google that term for an idea of what that's about

 

[scrapart]

sorry scrap .. missed it while trying to make a living

tough to make out your diagram, try drawing it out again .. but from what i can see i would say no it won't work .. water will only flow the easiest way possible unless it's forced to flow by pumps you need to manifold the lines going into the floor and the line set going to the addition and set it up in reverse return .. google that term for an idea of what that's about

Did not mean anything rude! I m just trying to do the addition the right way !

 

[scrapart]

So after reading this is how I understand my system should be like....


O if I have gave off the impression that I don't work well Im laid off for the winter .

 

[anthony666]

like this .. the blue stripey bit is each floor loop, but one of them is the line set out to the addition .. when you get the line set out to the addition do the same thing, splitting off into 2 small loops .. the way it's piped the last one out is the first one back, this equalizes the pressure in each line so the flow splits between each loop fairly evenly

it's one of those riding a bicycle type things .. when you grasp the concept it's actually very very simple, but the initial wrapping your noggin around it can be complicated

 

[tdkkart]

You want to heat both the garage and the addition to the same temps, or heat them seperately with different T-stats??
If using 2 T-stats it's easily done with either 2 pumps, or 2 zone valves.

I have my system set up using 2 pumps with internal check valves so that when pump #1 is running the check valve in pump #2 prevents loop #1 from reverse feeding loop #2 and vice-versa. It's easy to see with a picture but I don't have one here at the moment.
I also set up and "priority" relay so that only one of my pumps can run at a time since my heater isn't quite big enough to heat both zones at the same time. It is in a NORMAL winter, but not this winter.

 

[scrapart]

Ant= that ; basicly like my drawing except I need to add two manifolds out on the addition to have the two loops of 85ft . Takkart My plan is to control the main heat in the addition then when the addition is heated to 65 the garage will be what ever temp ..

 

[anthony666]

Ant= that ; basicly like my drawing except I need to add two manifolds out on the addition to have the two loops of 85ft . Takkart My plan is to control the main heat in the addition then when the addition is heated to 65 the garage will be what ever temp ..

cool .. take lots of install pics