In floor heat help.

[wolverine22391]

I have been looking and still haven't found a answer yet. I am curious on what type of pex and size you use, and why. I am also planing on installing a drive that is 162' long, 18' wide up too 130' from the poll barn which goes into a curve on the east side widening out to a 32' x 20' pad in front of the poll barn. The west side of the drive is a continuous straight edge of 162'. Thank you for your help, and advice.

 

[Bondo]

I am curious on what type of pex and size you use, and why.

Ayuh,.... In the slab I'm pourin', I'm usin' 1/2" oxygen barrier pex, as that's what it calls for in my application,....

On the wooden floor above, I used the oxygen barrier rubber hose, same size, as I was told it's quieter than plastic pex against the wood,...

You ask 'bout in-floor heatin', 'n then go on 'bout the driveway,...
Are ya thinkin' snow removal,..??
Have ya got a gas/ oil well on the property,..??

 

[Lootenny]

I used NIBCO PEX, and on their website you can submit info on your building, and they will tell you that you need X number of loops that are Y long. In general, it seems you need 1' of tubing for every 1 sq.ft. of floor space. Once you supply a copy of the receipt for having purchased the PEX, they will generate a diagram of how the loops should be laid out.

I'm sure that the other suppliers known on here such as pexheat.com, blueridgecompany.com, etc, can do the same thing. Most installations call for 1/2" PEX, though there are two companies that sell a 7/8" proprietary tubing that you can't get anywhere else. I'm not sure what the benefits and downsides of that are.

Good luck!

 

[wolverine22391]

Quote:
I am curious on what type of pex and size you use, and why.
Ayuh,.... In the slab I'm pourin', I'm usin' 1/2" oxygen barrier pex, as that's what it calls for in my application,....

On the wooden floor above, I used the oxygen barrier rubber hose, same size, as I was told it's quieter than plastic pex against the wood,...

You ask 'bout in-floor heatin', 'n then go on 'bout the driveway,...
Are ya thinkin' snow removal,..??
Have ya got a gas/ oil well on the property,..??

Yes snow removal as in in slab set up in my driveway is what I meant.

 

[wolverine22391]

My goal is snow removal, and I plan on using a wood boiler as my heat source since wood is free for me. What is an average type of spacing used for this kind of application, and does it matter what kind of pex? Thank you I am going to check out those sites

 

[Bondo]

Ayuh,.... The 1/2" pex will be just fine,.... so long as it's an oxygen barrier type,....

Yer gonna need to run antifreeze, unless ya heat it continuously,...

Spacin' could be just in the wheel tracks, or for the entire slab,....

I heat my house with a homemade outdoor wood boiler,...
I can't imagine heatin' the entire driveway too,.....

 

[shelbyz28]

I believe a lot of times the snow melt systems use 1" or larger pex to transport the huge amout of BTUs required for melting the snow, perhaps shorter loops too. There is some documentation out there how to properly design a snow melt system, but there are lots of variables; wind, outside temperature, snowfall rate, sun load....

Bottom line, keep doing your research so it has a chance of working as intended.

 

[finn]

Plan on biweekly delivery of logs to feed the beast.

 

[shelbyz28]

I wouldn't get too discouraged about the fuel usage, put the pex in right and then see how much you want to run it. Some people fire theirs up when a snow storm is forecast, some have the luxury of waiting till it's coming down, then there are business who leave it running most/all winter. That's when it gets crazy.

 

[dfiler2]

Most snow melt systems use 1/2" PEX and some driveway systems heat the entire slab and others only the wheel tracks. You may want to consider separate loops coming up the driveway so you can play around with it some. Many people also use controllers that will start circulating water as soon as the snow starts falling, others use WIFI controls to activate the system depending on the weather outlook. Even in the parking area I would pay close attention to the placement of the loops so you can melt the whole area if you want or just smaller pathway areas.

 

[wolverine22391]

Some great ideas and thank you for the help. I kind of have an idea now. Just curious why the oxygen barrier per over regular?

 

[BadgerBoilerMN]

I used NIBCO PEX, and on their website you can submit info on your building, and they will tell you that you need X number of loops that are Y long. In general, it seems you need 1' of tubing for every 1 sq.ft. of floor space. Once you supply a copy of the receipt for having purchased the PEX, they will generate a diagram of how the loops should be laid out.

I'm sure that the other suppliers known on here such as pexheat.com, blueridgecompany.com, etc, can do the same thing. Most installations call for 1/2" PEX, though there are two companies that sell a 7/8" proprietary tubing that you can't get anywhere else. I'm not sure what the benefits and downsides of that are.

Good luck!

There are no benefits...

 

[BadgerBoilerMN]

Most snow melt systems use 1/2" PEX and some driveway systems heat the entire slab and others only the wheel tracks. You may want to consider separate loops coming up the driveway so you can play around with it some. Many people also use controllers that will start circulating water as soon as the snow starts falling, others use WIFI controls to activate the system depending on the weather outlook. Even in the parking area I would pay close attention to the placement of the loops so you can melt the whole area if you want or just smaller pathway areas.

Most snow melt systems employ 3/4" PEX. Few have the skill to design or install a snow/ice melting system (SIM) using 1/2" PEX. We use it for modest systems such as Class I residential drives or sidewalks.

Wheel tracks for mild climates, perhaps.

Play around with a SIM system?

WiFi SIMS, now were getting crazy!

Do a lot of SIM systems?

 

[BadgerBoilerMN]

The PEX diameter, length and spacing is dictated by the Class of SIM system you desire and your location.

This is all documented and available from ASHRAE. No competent designer does heated driveway design long-hand, since there are several good CAD programs on the market.

Then there is the control, pumps, anti-freeze and required output.

My own heated driveway averages 17 cents per square foot per season here in sunny Minnesota.

http://www.badgerboilerservice.com/snowmelt.html

If you are using a wood boiler to melt snow you want to consider using a flat plate heat exchanger between the snow and the boiler since propylene glycol does not like to be cooked and you don't want to buy the extra PG to fill the boiler unless you must.