Are you doing this to add a continous loop of hot at the sink? You will
definitely get the hot water quicker, but you will have loss. Your HWH may
cycle a little more than usual.

That being said I would definitely use copper, and pray that the copper
under slab is insulated. We are replacing alot of radiant tubing inn
concrete slabs due to breakdown of the pipes from the concrete ( at least I
think that is why it is breaking down) too late had a long week brain is
dead. Why not just put in a point of use hot water heater under the sink.
Depending on your electric rate that may be alot cheaper.

--
Bob Pietrangelo


www.comfort-solution.biz
On Time or Your Service Call is FREE
Preventive Maintenance Specialist




"Harry Everhart" wrote in message
...
I am going to be running a hot water line up and over from the water
heater to a kitchen sink about 90 feet away. Presently the water goes
through a 3/4 copper pipe buried in the concert slab. I am going to run
a 1/2 inch overhead pipe covered by insulation. I am doing this to get
hot water faster - and not lose a lot of heat to the concrete slab.

I am the guy that was asking how much water is in a 1/2 inch by 100 feet
copper tube.

I went to Lowes and Home Depot and talked to the help there. I have
always used copper in the past sweating my own fittings. Both places
asked me to consider CPVC - it is much cheaper and they said easier to
work with. Is it durable?

They also showed me coils of copper tubing - in K and L category. What
is the difference in K and L copper tubing? It is more expensive than
CPVC - but you would have only one coupling overhead - not like the CPVC.

They also showed me union joints that join CPVC and copper.

I appreciate comments on this job.

Harry