Home Ownership (misc.consumers.house)

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Posted to misc.consumers.house
external usenet poster
 
Posts: 55
Default Hot Water on Demand

Hot Water on Demand

Waiting for hot water at the sink or shower can waste thousands of
gallons of that precious resource every year. The wealthy have long
been able to overcome this problem through the use of highly expensive
hot water recirculation systems that were built into their hot water
heater. These systems are different than our own. Where we have a hot
and a cold line recirculation installations have two hot lines and one
cold. Three lines instead of two plus a recirculation pump at the
water heater. With this elaborate system, hot water is almost
instantaneous at every fixture in their home. The thermostatically
controlled pump shuts off when water in the line is hot end to end. As
soon as the water cools, the pump starts again. Short of adding an
additional water heater, this technique has, for years, been the most
cost-effective method of getting instant hot water to all plumbing
locations in the home – helping to cut down on wasted water by
eliminating the wait for warmth. By the way, there is a caveat. It
sure is nice not having to deal with 38-degree water at 5 A.M. on a
chilly winter morning. Instant hot is very cool – if you get the pun.

Over the last two decades Hot Water on Demand systems have flourished.
Everyone has gotten into the act. These systems have become simplified
beyond belief and cost really has come down while installation has
become something that most modestly skilled DIY’ers can do themselves
in an hour or two.

Auxiliary Water Tanks:
When hot water on demand is mentioned some think of a small auxiliary
water heater placed beneath the sink that provides hot water at all
times. A secondary water heater if you will. These work well to solve
the problem at a given sink. However, shower water – where most waste
occurs – cannot be so easily retrofitted with such a unit. Another
drawback to auxiliary heating tanks is that electrical is required for
each unit – usually a dedicated circuit because of the great amount of
current required to heat the water. Important to keep in mind that
these units usually only handle one sink per. If you have 3 or 4 sinks
you’ll be looking at a cost of at least $2,000 in heating units and
electrical installations – not practical in our estimation.

Pump Systems:
Our idea of hot water on demand is a bit different than adding tanks.
Why not – we’re guys – we like adding motors instead. Also, our choice
of new technology utilizes that once used by only the wealthy, but
with a couple of really cool twists that what’s new so inexpensive to
purchase and so easy to install. And all without hot water pipe number
two we might add. The theory is a brain twister because it is so very
simple. There are two types that we like.

Grundfos Comfort System
Our first choice is one that involves the installation of a motor at
the water heater and a small plastic pipe under the sink known as a
crossover:

• First, a very small high speed, low volume (extremely quiet pump) is
added to the outgoing hot water line at your water heater. We took
about 20 minutes to install ours. The pump is regulated by a simple
timer that causes it to run during those times of the day or night
when you feel you will want hot water on demand. We had to use an
extension cord to provide 110v power to our unit. The pump can be set
up to run for as little as15 minutes once a day or 24/7 – you choose
when you will need or want the convenience of automatic hot water when
you turn on the faucet.

• In these systems there is no need for a secondary hot water line.
Instead there is a 6 inch long plastic “crossover” pipe that connects
to the faucet which lies farthest from the water heater – and thus
impacting all fixtures in between. The crossover connects the hot and
cold water lines together and contains a check valve so that the cold
water won’t back up into the hot water line. The crossover is also
thermostatically controlled and when it senses cold water in the hot
water line it opens and lets the water silently run into the cold
water line (and back into the water heater). This simple process
continues until the hot water arrives at the faucet. Instant hot water
at every location in your home with 2 simple additions – a pump and a
crossover. When the crossover senses the heat it shuts off. The
process repeats when the water cools (as long as the timer is set in
the on position). What could be simpler?

The Metlund D’Mand System
Another on demand system the Metlund D’Mand system works especially
well with thankless and hybrid water heaters. In fact it is the only
one we know of that does. This system differs from the Grundfos in
that it requires the pump to be installed under the sink (rather than
at the water heater). Interestingly, the pump, thermostat and the
crossover in the Metlund unit come in a single package (as a combined
unit) making installation quicker and by far the least complicated. As
with the Grundfos the Metlund needs a 110v power source.
Unfortunately, with the Metlund you will probably have to add one
since we don’t usually find outlets under sinks.

A manual switch is provided with the standard unit so that the pump
can be turned on only when needed or wanted. An optional remote relay
allows the use of a wireless control that turns the unit on from
anywhere in the home. For example: you get up in the morning and
before hitting the potty (or during) simply hit a remote relay and the
system starts and runs only as long as it takes to heat the water all
throughout the home – showers sinks – everywhere. Water gets hot and
the Metlund system shuts off. Now that’s cost effective hot water
management. And not one drop of water spilled with either of the tow
types of recirculation units. User management or not this system is
truly the most “on demand” of them all. Metlund’s mid-priced unit, the
S-70 runs about $400 bucks with one remote control and one manual
switch.

The Grundfos kit with a pump and a crossover retails for about $450.

It should be kept in mind that both of the systems that we have
mentioned recommend a single installation. However, in our home we
have two crossovers, because the water heater lies in the middle of
our plumbing system rather than at one end. So here’s how the prices
play out when two units are needed:

Metlund
$400..................First Unit
$400..................Second Unit
$200 each.........Electrical
$1,000...............Total Cost

Grundfos*
$450...................First Unit
$50.....................Second Unit
$0.......................Electrical
$500...................Total Cost
*System does not work well with on demand or hybrid water heaters.

Although the Metlund come out more expensive in the short haul the
Grundfos will cost more money over the years because it runs by timer
rather than on price demand.

http://www.onthehouse.com/wp/20090318
Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
On-demand water heater [email protected] Home Repair 12 February 1st 07 04:54 PM
Alamo demand water softener [email protected] Home Repair 0 December 28th 06 01:18 AM
On demand hot water SteveB Home Repair 2 November 14th 05 02:09 AM
on demand electric water heater gcroix Home Repair 3 February 2nd 05 03:44 PM
Water softener timer or 'on demand' for well water? darford Home Ownership 0 August 13th 04 07:11 AM


All times are GMT +1. The time now is 12:02 PM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"