Recirculating Pump Selection for Residential Hot Water
 

I am considering adding a hot-water recirculation system to a
residential re-piping job I am planning for my home. Due to the design
of the home (two stories with full basement and full attic), the
re-piping will serve the second floor from an attic manifold (near the
water heater)and the first floor from a basement manifold (17' distant
from the water heater). The water heater is located on the second
floor.

I need to know what pump (specs, brand/model, if possible) should be
selected for a 3/4" recirculation loop, where the lowest point of the
loop will be approximately 17' below the water heater return. Also,
where should such a pump be placed, at the top of the loop or bottom,
or does it not matter? Any other considerations?

P.S. Code does not permit second water heater in basement, due to
waterfront flood zone, so that solution is out.

Thanks in advance.

Recirculating Pump Selection for Residential Hot Water
 

On 4 Apr 2006 06:00:45 -0700, "tacker" wrote
(with possible editing):

I am considering adding a hot-water recirculation system to a
residential re-piping job I am planning for my home. Due to the design
of the home (two stories with full basement and full attic), the
re-piping will serve the second floor from an attic manifold (near the
water heater)and the first floor from a basement manifold (17' distant
from the water heater). The water heater is located on the second
floor.

I need to know what pump (specs, brand/model, if possible) should be
selected for a 3/4" recirculation loop, where the lowest point of the
loop will be approximately 17' below the water heater return. Also,
where should such a pump be placed, at the top of the loop or bottom,
or does it not matter? Any other considerations?

P.S. Code does not permit second water heater in basement, due to
waterfront flood zone, so that solution is out.

Thanks in advance.

Mine is a TACO Cartridge Circulator Model 006-84 - (very small even
though it is a 28 room home). You might want to put a dial indicating
thermometer on the return line. That will help you set the frequency
and "on" time. You can have multiple returns. The pump is controlled
by the computer on the boiler (in my case a Buderus). Mine runs a few
times each hour for a short period of time and shuts off at night. It
does not matter where you place the pump (since it's a closed system),
but near the water heater is a logical place. Obviously it makes
sense to insulate both hot water feed and return lines.

--

Larry
Email to rapp at lmr dot com

Recirculating Pump Selection for Residential Hot Water
 

Tacker-

I've only had one house w/ a hot water recirc pump. It was located
right at the water heater & plumbed into the water heater drain port.

I didn't do the installation, it was "professionally" done whne the
house was built

It was a Grundfo, as far as I know they're somewhat pricey but the one
I had ran 24/7 for the 13 years I owned the place with no problems.

here's a link to a pretty good supplier

http://www.plumbingsupply.com/circpump.html

the pump in the photo looks just like mine. the install shown has a
timer AND a thermostat..............mine just ran all the time

The site has a general installationscheme but maybe you can ask them
about your special sitiation. IMO the far left hand point of the
sketch looks like the right place for your pump, if you can easily put
it there.

pumps work best at (near) the low point of the loop (my w/h was the low
point)

ideally, the sensor for the thermostat should be at the hot water
delivery point
second choice would at the water returning to the w/h

the return water should be dumped into either the drain port? (as was
done in my install) but my gut tells me it makes better sense to dump
it back via the cold water inlet (a check valve might be a good idea)
but it probably doens't make much difference since my old install
worked fine

my pump was very low powered, you don't need much plus you want to keep
the electrical cost low.

wrt to pump specs, since it's a closed loop you really don't need much
hp, you're just overcoming the friction losses due to flow

I'd ask them what pump they sugggest, you'll just need to know the loop
length, tube material & sizes.

cheers
Bob

Do you want those Wirsbo tables?

Recirculating Pump Selection for Residential Hot Water
 

Thanks. Would love those tables via e-mail.

Recirculating Pump Selection for Residential Hot Water
 

"tacker" wrote in message
oups.com...
I am considering adding a hot-water recirculation system to a
residential re-piping job I am planning for my home. Due to the design
of the home (two stories with full basement and full attic), the
re-piping will serve the second floor from an attic manifold (near the
water heater)and the first floor from a basement manifold (17' distant
from the water heater). The water heater is located on the second
floor.

I need to know what pump (specs, brand/model, if possible) should be
selected for a 3/4" recirculation loop, where the lowest point of the
loop will be approximately 17' below the water heater return. Also,
where should such a pump be placed, at the top of the loop or bottom,
or does it not matter? Any other considerations?

P.S. Code does not permit second water heater in basement, due to
waterfront flood zone, so that solution is out.

I believe the pump goes in the return pipe near the storage tank. I believe
they are quite small pumps and if you put them in the feed they can reduce
the flow.

Recirculating Pump Selection for Residential Hot Water
 

From what I have seen, the kind of pumps HD, or Lowes has, use a smaller
hose than 3/4". What I have seen gets the pump mounted at the farthest
source for hot water, and the return line from the pump goes back to the hw
tank. The diameter would probably have to do with the distance involved. The
pump runs all the time.
Can you just recirculate from manifold to manifold? Not sure what the
lengths of runs off of the manifold are, but that would make a difference
too.

--
remove one of the @'s unless you are a spammer.
"tacker" wrote in message
oups.com...
I am considering adding a hot-water recirculation system to a
residential re-piping job I am planning for my home. Due to the design
of the home (two stories with full basement and full attic), the
re-piping will serve the second floor from an attic manifold (near the
water heater)and the first floor from a basement manifold (17' distant
from the water heater). The water heater is located on the second
floor.

I need to know what pump (specs, brand/model, if possible) should be
selected for a 3/4" recirculation loop, where the lowest point of the
loop will be approximately 17' below the water heater return. Also,
where should such a pump be placed, at the top of the loop or bottom,
or does it not matter? Any other considerations?

P.S. Code does not permit second water heater in basement, due to
waterfront flood zone, so that solution is out.

Thanks in advance.

Recirculating Pump Selection for Residential Hot Water
 

tacker wrote:

I am considering adding a hot-water recirculation system to a
residential re-piping job I am planning for my home. Due to the design
of the home (two stories with full basement and full attic), the
re-piping will serve the second floor from an attic manifold (near the
water heater)and the first floor from a basement manifold (17' distant
from the water heater). The water heater is located on the second
floor.

I need to know what pump (specs, brand/model, if possible) should be
selected for a 3/4" recirculation loop, where the lowest point of the
loop will be approximately 17' below the water heater return. Also,
where should such a pump be placed, at the top of the loop or bottom,
or does it not matter? Any other considerations?

P.S. Code does not permit second water heater in basement, due to
waterfront flood zone, so that solution is out.

Thanks in advance.


I installed one of these in my house

http://www.lainginc.com/act303.htm

about 4 years ago. I've been very happy with it runs silently and it was
very simple to install. IRC it was just over $200.

--
Art