Re: Help for the Cat shelter

[nobody@xxxxxxxxxxxx (Dave Houston)]

There are a few kits available designed for controlling toaster ovens,
turning them into programmable reflow ovens for soldering of surface mount
components. They use triacs to control a resistive heating element. I would
think they could be modified for this task as the wattage is about the same
although the tempertures are much higher in the small, convection ovens. The
price is within your budget.

     http://www.sparkfun.com/commerce/product_info.php?products_id=81

If you post to their forums asking for help controlling the temperature in a
cathouse I'm sure Nathan will offer suggestions.

One caveat - you really need a failsafe mechanical overide in case of an
electronic malfunction.

Jim Baber <jim@xxxxxxxxx> wrote:

>    I am looking for an inexpensive solution to controlling the output
>of 1500 Watt oil filled heaters in six 400 sq. ft. outbuildings.  Each
>of these buildings provides shelter for 50 to 100 domestic cats that
>this no kill animal shelter supports.  The intent is to maintain each
>building's temperatures at a minimum of 45  to 50 degrees.  (cats do
>have fur coats!)
>
>    These heaters are relatively new (6 months), but, their controls are
>of the hi - med - low type and a thermostatic control is needed since
>the cats themselves can generate a significant amount of heat in a
>building that size.  I can see a regular thermostat used to energize an
>x10 appliance switch with a relay. But I am looking for a good solution
>for less than $100 each, because this tax exempt operation does really
>need the help.
>
>    The shelter's Feb. 2005 power bill was $683 (4,517 kWh) and the Feb.
>2006 bill was $2,600 (8,014 kWh).  This in was in spite of 500 kWh of
>new solar PV.  The big problem was PG&E's "11% AVERAGE" rate increase
>(Jan. 1) was primarily at the expense of heavy users.  This was because
>of the structure of PG&E's surcharges on heavy users.  You can tell how
>badly it affected The Cathouse On The Kings
><http://www.cathouseonthekings.com/> shelter, because, the effective
>rate went up from $0.15120 to $0.32443, and that is more than a 100%
>increase for each kilowatt used.  OUCH!!!
>
>--
>Jim Baber
>Email jim@xxxxxxxxxxxxxxx
>1350 W Mesa Ave.
>Fresno CA, 93711
>(559) 435-9068
>(559) 905-2204 (Verizon IN cellphone (to other Verizon IN accounts))
>See 10kW grid tied solar system at "http://www.baber.org/solarpanels.jpg";
>See solar system production data at "http://www.baber.org/solar_status.htm";