Electricity bill - OT

Chad Leigh -- Shire.Net LLC chad at shire.net
Tue Feb 8 10:15:39 PST 2005

On Feb 8, 2005, at 10:54 AM, Henry Miller wrote:

> On 2/8/2005 at 10:30 Chad Leigh -- Shire.Net LLC wrote:
>> On Feb 8, 2005, at 4:19 AM, Ted Mittelstaedt wrote:
>>>> -----Original Message-----
>>>> From: owner-freebsd-questions at freebsd.org
>>>> [mailto:owner-freebsd-questions at freebsd.org]On Behalf Of Chad Leigh
> --
>>>> Shire.Net LLC
>>>> Sent: Monday, February 07, 2005 8:29 PM
>>>> To: freebsd-questions at freebsd.org
>>>> Subject: Re: Electricity bill - OT
>>>> A lot of new-built houses in the US are installing continuous
>>>> circulation systems for hot water, which greatly reduces the time
> the
>>>> HW heater is running, since when you turn on the hot water, you get
>>>> instantaneous hot water and don't have to run a ton of water before
> it
>>>> gets hot, which reduces the amount of HW wasted.
>>> This is a gimmick built to sell houses, a cool one, but only in hot
>>> climates does it make much difference.  In cooler climates the heat
>>> from the standing water in the pipes just makes the furnace run
> less,
>>> thus the savings are a wash.
>> That does not make sense.  The savings is in running the hot water
>> heater less.  Houses that care about energy efficiency have the hot
>> water pipes insulated anyway so it would not help in cooler climes.
>> The goal is to run the hot water heater less, which you achieve when
>> you constantly circulate the hot water through the hot water pipes,
>> instead of letting it get cold and have to run a ton when you  need a
>> lot of water.
> That does not make sense.  IF the pipes were perfectly insulated there
> would be no need for this loop because the water in the pipes would be
> hot.   However there is no perfect insulation, so you keep the water in
> the pipes warm by re-circulating it.  Each time water goes through the
> pipes it loses a little heat, which the water heater then has to make
> up for.   So these loops waste energy, but it is considered worth it
> because you get hot water without having to wait.

The data I saw a year or two ago showed that these were more energy 
efficient than the standard model of waiting for a minute or two for 
the hot water to purge the colder water from the pipes.  It has added 
benefits, and the benefits may be related to this (ie, constantly 
circulating water means you run it less which may be where the savings 
come in).  I do not have the data in front of me now, but it was an 
interesting proposition.  And more energy efficient.  Not a gimmick.

>>>> Also, the new
>>>> tankless HW heaters look interesting...
>>> those have been around for at least 20 years.  As most of them are
>>> electric, not natural gas, your going to pay more money for heating
>>> water with a bunch of those than with a central gas water heater.
>> The ones I have seen, the newer models, are GAS and are very
> efficient.
>>  Maybe you need to get out more?
> I've seen both types.  Both have been around for 20 years.

Computers have been around about 50 years, but to compare todays 
computers to those of 50 years go is ridiculous.   Do you not think 
that mayb e hot water technology has advanced some in 20 years?

>  Electric
> ones seem more common, but to replace a tank type water heater you need
> 80 amp service to it, which is difficult to work with so few people
> have or use them.

I was specifically refering to new technology, I believe gas based, 
tankless water heaters that are more energy efficient and can lower 
your energy needs.  To compare this to 20 year old technology is 


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