On 2015-10-20 12:17 PM, sf wrote:

> Most people locate their furnace, water heater and air conditioner
> centrally, so run length isn't an issue. As far as how long it takes
> for hot water to hit the faucet,


Most people don't have a say in where the furnace and heater go. They
are there when they buy the place, and they are usually installed to
maximize space. My former neighbour is the only person I know who had
a furnace moved. When they switched to gas the furnace was much smaller
than the previous old oil furnace. The moved it to the corner of the
next room and gained an open room.

One needs to consider the location of the rooms to be plumped. If they
are all one one side of the house it makes sense to have the heater
located there. If they are at opposite sides of the house it doesn't
make much difference in the amount of material because you can go from
one end to the other or from the middle to two ends and it will be about
the same amount of piping There won't be much difference in the amount
of heat lost through radiation but it there will be a difference in the
time it takes to get the hot water. The further the water runs from the
heater the longer it will take to purge the cold water and get the hot
there.



> the size of water heater isn't your
> problem (unless you take long showers) - but the size of your pipes
> is. Either your pipes are corroded or just plain too small. Reroute
> them to a direct run and/or replace them with a larger size and your
> hot water will reach the faucet faster.



Larger diameter pipe will not make the hot water come faster. On the
contrary, there will be more cold water in the pipes to be purged. I
suppose you could run massive pipes and huge fixtures, but there is
limited water pressure and the big restriction is at the faucet. The
more cold water there is sitting in the pipes, the longer it is going to
take to get hot.