Prev: Ping Larkin
Next: ZVS converter - snubber helpful at turn-off?
From: mpm on 19 Oct 2009 16:30
On Oct 19, 12:13 pm, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
wrote:
> mpm wrote:
> > On Oct 18, 8:54 am, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
> > wrote:
> >> mpm wrote:
> >>> On Oct 16, 5:12 am, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
> >>> wrote:
> >>>> Why not use a solar water heater then? At US latitudes they should be
> >>>> commonplace and available relatively cheaply.
> >>> It's only cheaper if you don't factor in the cost of a new roof, or a
> >>> whole new house!
> >>> You can loosely translate that as "Hurricanes".
> >> The Japanese seem to manage OK with them although they call their
> >> "Hurricanes" as Typhoons the effect is pretty much the same.
>
> >> Are you saying that US homes are so shoddily built that the additional
> >> load of a solar water heater on top would cause them to collapse in the
> >> wind of a hurricane ?
>
> >> Can't do much about tornadoes most things fly apart in those.
>
> > It's the wind force loading, not the weight that causes the problems.
> > To meet local code, it's VERY expensive.
>
> I don't remember seeing any Japanese houses fall down and we lived there
> through several powerful direct hit typhoons.
>
> > And regardless, my hot water bills are no so high as to justify the
> > risk of losing the whole house.
>
> That is a problem. Even though the capital cost is relatively low the
> total cost of hot water is tiny compared to space heating/cooling.
>
>
>
> > I wonder if Japan mandates solar use.
>
> I doubt it. This was long before AGW was even on the agenda. They like
> gadgets though and Japanese baths require copious hot water.
>
> Regards,
> Martin Brown- Hide quoted text -
>
> - Show quoted text -

Dude, respectfully, you are not listening.
Capital cost is NOT low. No matter what you compare it to.

As for the "doubting Thomas" attitude...
Shouldn't be too difficult for you to Google images of the thousands
of homes destroyed by Hurricane Andrew.

Here's one to get you started.
http://www.geocities.com/hurricanene/hurricaneandrew.htm

I submit to you that the roofs in the photos are not substantially
strengthed by the addition of a solar hot water heater.....




From: krw on 19 Oct 2009 20:06
On Mon, 19 Oct 2009 13:30:20 -0700 (PDT), mpm <mpmillard(a)aol.com>
wrote:

>On Oct 19, 12:13�pm, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
>wrote:
>> mpm wrote:
>> > On Oct 18, 8:54 am, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
>> > wrote:
>> >> mpm wrote:
>> >>> On Oct 16, 5:12 am, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
>> >>> wrote:
>> >>>> Why not use a solar water heater then? At US latitudes they should be
>> >>>> commonplace and available relatively cheaply.
>> >>> It's only cheaper if you don't factor in the cost of a new roof, or a
>> >>> whole new house!
>> >>> You can loosely translate that as "Hurricanes".
>> >> The Japanese seem to manage OK with them although they call their
>> >> "Hurricanes" as Typhoons the effect is pretty much the same.
>>
>> >> Are you saying that US homes are so shoddily built that the additional
>> >> load of a solar water heater on top would cause them to collapse in the
>> >> wind of a hurricane ?
>>
>> >> Can't do much about tornadoes most things fly apart in those.
>>
>> > It's the wind force loading, not the weight that causes the problems.
>> > To meet local code, it's VERY expensive.
>>
>> I don't remember seeing any Japanese houses fall down and we lived there
>> through several powerful direct hit typhoons.
>>
>> > And regardless, my hot water bills are no so high as to justify the
>> > risk of losing the whole house.
>>
>> That is a problem. Even though the capital cost is relatively low the
>> total cost of hot water is tiny compared to space heating/cooling.
>>
>>
>>
>> > I wonder if Japan mandates solar use.
>>
>> I doubt it. This was long before AGW was even on the agenda. They like
>> gadgets though and Japanese baths require copious hot water.
>>
>> Regards,
>> Martin Brown- Hide quoted text -
>>
>> - Show quoted text -
>
>Dude, respectfully, you are not listening.
>Capital cost is NOT low. No matter what you compare it to.
>
>As for the "doubting Thomas" attitude...
>Shouldn't be too difficult for you to Google images of the thousands
>of homes destroyed by Hurricane Andrew.
>
>Here's one to get you started.
>http://www.geocities.com/hurricanene/hurricaneandrew.htm
>
>I submit to you that the roofs in the photos are not substantially
>strengthed by the addition of a solar hot water heater.....

Think: Wing.
From: Michael A. Terrell on 20 Oct 2009 04:22

krw wrote:
>
> On Mon, 19 Oct 2009 13:30:20 -0700 (PDT), mpm <mpmillard(a)aol.com>
> wrote:
>
> >On Oct 19, 12:13 pm, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
> >wrote:
> >> mpm wrote:
> >> > On Oct 18, 8:54 am, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
> >> > wrote:
> >> >> mpm wrote:
> >> >>> On Oct 16, 5:12 am, Martin Brown <|||newspam...(a)nezumi.demon.co.uk>
> >> >>> wrote:
> >> >>>> Why not use a solar water heater then? At US latitudes they should be
> >> >>>> commonplace and available relatively cheaply.
> >> >>> It's only cheaper if you don't factor in the cost of a new roof, or a
> >> >>> whole new house!
> >> >>> You can loosely translate that as "Hurricanes".
> >> >> The Japanese seem to manage OK with them although they call their
> >> >> "Hurricanes" as Typhoons the effect is pretty much the same.
> >>
> >> >> Are you saying that US homes are so shoddily built that the additional
> >> >> load of a solar water heater on top would cause them to collapse in the
> >> >> wind of a hurricane ?
> >>
> >> >> Can't do much about tornadoes most things fly apart in those.
> >>
> >> > It's the wind force loading, not the weight that causes the problems.
> >> > To meet local code, it's VERY expensive.
> >>
> >> I don't remember seeing any Japanese houses fall down and we lived there
> >> through several powerful direct hit typhoons.
> >>
> >> > And regardless, my hot water bills are no so high as to justify the
> >> > risk of losing the whole house.
> >>
> >> That is a problem. Even though the capital cost is relatively low the
> >> total cost of hot water is tiny compared to space heating/cooling.
> >>
> >>
> >>
> >> > I wonder if Japan mandates solar use.
> >>
> >> I doubt it. This was long before AGW was even on the agenda. They like
> >> gadgets though and Japanese baths require copious hot water.
> >>
> >> Regards,
> >> Martin Brown- Hide quoted text -
> >>
> >> - Show quoted text -
> >
> >Dude, respectfully, you are not listening.
> >Capital cost is NOT low. No matter what you compare it to.
> >
> >As for the "doubting Thomas" attitude...
> >Shouldn't be too difficult for you to Google images of the thousands
> >of homes destroyed by Hurricane Andrew.
> >
> >Here's one to get you started.
> >http://www.geocities.com/hurricanene/hurricaneandrew.htm
> >
> >I submit to you that the roofs in the photos are not substantially
> >strengthed by the addition of a solar hot water heater.....
>
> Think: Wing.


And not a prayer.


--
The movie 'Deliverance' isn't a documentary!
From: JosephKK on 22 Oct 2009 08:26
On Thu, 15 Oct 2009 13:46:48 +0100, baron
<baron.nospam(a)linuxmaniac.nospam.net> wrote:

>Hi Guys,
>
>I'm doing a hobby project to build a timer that can be used to turn on a
>relay at a pre-determined time and then turn it off after a delay.
>I also want to use a temperature sensor to override the relay but only
>during the time period that is programmed.
>
>The idea is to turn on a water heater for a pre-determined period but to
>use a thermostat to control the temperature during this period.
>
>I have suggested using a relay because the heater is rated at 3.5Kw
>240/250 volts, 50hz AC. Low voltage relays are available that can
>handle this load with ease. The heater has a safety cutout built in
>that should prevent boiling dry.
>
>I am aware that I can buy programmable motor driven timers very cheaply,
>however they are limited in contact loading and I would still need a
>relay for thermostat control.
>
>I thought this might make a nice PIC project. (Ducking) :-)

Sounds more like a 22V10 task to me. But i always prefer hardware to
firm ware.
From: JosephKK on 22 Oct 2009 08:57
On Thu, 15 Oct 2009 22:17:30 -0400, "Martin Riddle"
<martin_rid(a)verizon.net> wrote:

>
>
>"baron" <baron.nospam(a)linuxmaniac.nospam.net> wrote in message
>news:hb7g70$jul$1(a)news.eternal-september.org...
>> John Fields Inscribed thus:
>>
>>> On Thu, 15 Oct 2009 13:46:48 +0100, baron
>>> <baron.nospam(a)linuxmaniac.nospam.net> wrote:
>>>
>>>>Hi Guys,
>>>>
>>>>I'm doing a hobby project to build a timer that can be used to turn
>>>>on
>>>>a relay at a pre-determined time and then turn it off after a delay.
>>>>I also want to use a temperature sensor to override the relay but
>>>>only
>>>>during the time period that is programmed.
>>>>
>>>>The idea is to turn on a water heater for a pre-determined period but
>>>>to use a thermostat to control the temperature during this period.
>>>>
>>>>I have suggested using a relay because the heater is rated at 3.5Kw
>>>>240/250 volts, 50hz AC. Low voltage relays are available that can
>>>>handle this load with ease. The heater has a safety cutout built in
>>>>that should prevent boiling dry.
>>>>
>>>>I am aware that I can buy programmable motor driven timers very
>>>>cheaply, however they are limited in contact loading and I would
>>>>still
>>>>need a relay for thermostat control.
>>>>
>>>>I thought this might make a nice PIC project. (Ducking) :-)
>>>
>>> ---
>>> View in Courier:
>>>
>>>
>>> +----------+
>>> | C O------|-----+
>>> | | NC | |
>>> | > |<--O--|--+ |
>>> +----------+ | |
>>> TSTAT | |
>>> | |
>>> | |
>>> +-------------|--|-----------------+
>>> | TIMER | | |
>>> | +------+ | | |
>>> AC>--+-| |----+ +---+ |
>>> | | | NO |
>>> | | [COIL]- - -| <--O
>>> | | | |
>>> AC>--+-| |-----------+ OC
>>> | +------+ |
>>> | [HEATER]
>>> | |
>>> +-----------------------------+
>>
>> Thanks John.
>> Your circuit is exactly what I had in mind. Its the timer and
>> temperature sensing circuits that I want to create electronic versions
>> of.
>>
>> The timer only needs to be accurate to a few minutes but needs to be
>> settable for any span within a 24 hour period. This is why I thought
>> that a PIC, with its programmability might be suitable.
>>
>> I have a rigid rod thermostat probe, but its way too coarse between
>> its
>> on/off switching points. Something around 12 - 18C between them. I
>> would hope to obtain a couple of degrees of hysteresis over say 50 to
>> 85C range.
>>
>> I was thinking diode or thermistor clamped to the bath to measure the
>> temperature more accurately.
>>
>> --
>> Best Regards:
>> Baron.
>
>A 10K(a)25 NTC and a pull up resistor on the 0-5v ADC of a pic will give
>you around 0.2c resolution.
>A good stable Vref would help too, Like a LM4040 instead of the supply
>voltage.
>
>Cheers
>
>
Fer crying out loud, we are talking about a water heater for domestic
use. 2 degrees C is plenty good control.
First  |  Prev  | 
Pages: 1 2 3 4 5 6 7
Prev: Ping Larkin
Next: ZVS converter - snubber helpful at turn-off?