# Heated Asphalt Driveway via Pex & Instant Hot Water?



## ED209 (Jan 4, 2010)

Has anyone tried heating a 1000sqft asphalt driveway with standard pex, using an instant hot water heater? 

A poor-mans heated driveway. 

I would like to try this but my hangups are:

1) what instant hot water heater will tolerate antifreeze running thru it?

2) how big of a instant hot water heater is needed?

3) where in depth do I bury the pex?

I want to fully recycle the water in the lines, making it totally separate from any other water source.

whadaya think?


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## Scuba_Dave (Jan 16, 2009)

Where are you located ? Makes a difference in how warm you need it
They do make driveway warming systems
I'm thinking just to melt ice etc ?
Not sure how pex would hold up to the asphalt & car traffic
And I doubt it is made for this use


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## ED209 (Jan 4, 2010)

*RE: Poor mans heated driveway.*



Scuba_Dave said:


> Where are you located ? Makes a difference in how warm you need it
> They do make driveway warming systems
> I'm thinking just to melt ice etc ?
> Not sure how pex would hold up to the asphalt & car traffic
> And I doubt it is made for this use


Hey SD, thanks for the reply,

Upstate New York, Capital Region.


I know they sell hydronic systems for instalation in concrete pads but I have yet to see one thats made for asphalt, that isnt a bank breaking electric cable system.

I figure my system would come to $1200- or less, minus Pavement.

...If it can be done.


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## Bondo (Dec 8, 2007)

Ayuh,... I'm a Blacktopper in the summer, up here in Jefferson county,...
In order to do what you want,...
You'd need to bury the pex under an inch of stone, below the level of the bottom of the blacktop...
After the tubing is installed,+ the cuts are reshimmed back to the level of the finished blacktop grade(an inch of stone,+ the depth of the blacktop), It would need to be Topped over with atleast another inch of top coat...

Do you have enough reveal to top the existing driveway with another Inch, without creating drainage issues,..??

With the expence of the installation, along with the energy bill for running it,...
I'd think you could pay a kid to shovel it for a Long time... Or, buy a snowblower...


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## PaddyKevin (May 22, 2008)

*Heated Driveway Idea*

I am in Orchard Park, outside of Buffalo, and keep thinking of this every darn winter. An idea has come to mind with using heated water. I am most interested in putting in two heated strips to take care of the areas "where the sun don't shine". They are in shade most of the day in the winter.

I was thinking of putting 50 gallon containers in the basement and then using a pond pump to circulate the heated medium up and through the system. If the tubing carries one tenth or less the amount of the water mixture then it seems to me that it might work. I would be putting these under pavers.

How is this not doable?

Thanks
Kevin


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## Lightfoot (Jan 16, 2011)

I used to own a carwash with heated bay floors. Mine was a boiler with a circulating pump (just a small one). I had thought that if the boiler ever took a dump, i might take a look at the on demand type heater, but i also wondered if it would handle the antifreeze/water mixture too. Ya don't have to get the liquid hot-just slightly warm, so I wouldn't think it would have to be a terribly large heater. I kept my thermostat in the bay floor set to come on at 38 degrees. It was a closed loop system with only a 10 gallon reserve tank feeding the boiler. The lines were in in concrete though-not blacktop. For years, my wash was the only one in town with heated floors and in the heart of winter, i was busy daylight to dark. The rest of the washes in town would close because their bays would have a foot of ice in them. 
I don't know why the system would not work under blacktop as well if the prep work was done right. I'm thinkin that you'd have to use anti-freeze mixture made for aluminum, as i believe some of the internals of the on demand heaters are aluminum. At least the one i had was. It was a paloma brand.


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## 4lambs2 (Feb 9, 2011)

*Heated Driveway*

I've been seriously considering this same project in the Pittsburgh area. I think the RV type anti-freeze would be best since it is not as thick and safer to use. I have seen "PEX" type tubing sold online which is made for outdoor/underground use. A pump would still be needed to move the water/anti-freeze through the closed system. Any idea how large of a pump would be needed? I guess it will depend on the grade and the length of tubing.


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## yellabelly (Apr 17, 2013)

That is a pretty large sqft with hydronics for just a hot water heater. The water gets cooler at the end of the loop FYI


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## jmon (Nov 5, 2012)

Thread is over 5 years old. I think they got it figured out.


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## yellabelly (Apr 17, 2013)

It didn't look like they figured it out. Did you read it?


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## jmon (Nov 5, 2012)

Yes I read it. Just figured it was over 5 years old and the op never posted an update or never did anything and forgot about it.


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