How pumps work


Hot Water - Why Does it Take so Long?

Do you have to stand naked and shiveringthe same length.Â
waiting for the shower to get hot?ÂIn the winter it will take longer than
Why does it take so darned long to getin the summer, since the ambient
hot water to the fixture?temperature will be lower. The colder
There are a number of variables involvedthe ambient temperature the more heat
in getting the hot water from your waterthe pipe will suck out of the water and
heater to your fixtures. Obviouslyso the longer it will take.Â
the distance from the water heater toInsulating the pipes does help a little.
the fixtures is a major factor in how In the old days you could get shower
long it takes to get hot water. Anotherheads that would permit flows of over 7
important factor is what kind of pipe isgallons per minute…but now days
used in your plumbing system? Is iteverything is low flow. Most showers
galvanized iron pipe, copper pipe,now are limited to 2 gallons per minute
copper tubing, plastic pipe or maybeand many faucets are below 1 gallon per
some kind of plastic tubing?Âminute. This adds significantly to
Since the material that the pipe is madethe time it takes to get hot water.
out of can absorb heat from the water itThere are ways to speed up the delivery
is important as well. Other factorsof hot water to your fixtures. Use a
include whether or not the pipes arepump. A number of manufacturers offer
insulated, the ambient temperaturevarious types of hot water pumping
around the piping, and the speed of thesystems designed to provide speedy hot
water through the pipe.water to your fixtures.Â
One last thing to consider is what typeThe oldest style system just uses a pump
of water heater you have. If you haveto circulate hot water in a loop,
a storage type water heater where therethrough the hot water piping and back to
is a big tank full of hot water justthe water heater. With that type of
waiting to fill the pipes, you will getsystem you have nearly instant hot
it much faster than if you have awater. However, the circulating hot
tankless water heater. The tanklesswater loses a lot of heat energy so it's
heater has to first heat the water,expensive to run. Another problem is
before it can send it to you, increasingthat usually running a pipe from the
how long it takes.last fixture back to the water heater is
A gallon of water will fill 63 feet ofvery expensive.
 ½ inch galvanized iron pipe, 36Another option is a demand type hot
feet of  ¾ inch galvanized pipe, orwater system. With a demand type
20 feet of 1 inch galvanized pipe.Âsystem the cold water piping is used as
In the case of type K copper pipe, athe return line back to the water
gallon of water will fill 88 feet ofheater. When you want hot water you
½ inch pipe, and 44 feet of ¾ inch"demand" it by pressing a button. The
pipe.Âpump turns on and circulates the water
This means that if you run your faucetthrough the piping until hot water
at 2 gallons per minute, and you have 1reaches the pump. When the hot water
inch galvanized pipe, the water willreaches the pump it shuts off to prevent
travel 41 feet per minute. However,filling the cold water lines with hot
if you have ½ inch type K copperwater. Now you have instant hot water
pipe, the water will travel 176 feet perwhen you turn on the tap or shower, and
minute, quite a difference.you did not wastefully run water down
So the smaller the diameter of the pipe,the drain while you waited. With the
the faster the hot water will reach theright pump, the hot water can get to the
fixture, given the same flow rate.Âfixture twice as fast as normal too.
Since galvanized pipe has a much thickerIf you have to wait for lengthy periods
wall than the copper pipe and is muchto get your hot water, then by using a
heavier, it will absorb more heat energyhot water pumping system you will save
from the hot water as the water flowstime, water and energy. Some such
through it. So if you have galvanizedsystems claim water saving of up to
pipe it will take longer for you to get10,000 gallons a year for a family of
hot water than if you had copper pipe offour.



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