Airport Power

" wrote in message
ups.com...
....

For the next level, figure out a way to turn it on remotely!

Bill Hale who does it with X-10 but is looking for a cell
phone solution!



X-10.com has some sort of remote call in box gizmo thingie to do this....

On Thu, 29 Jun 2006 20:56:29 -0400, "Kyle Boatright"
wrote:

I need a trickle of electrical power about a dozen times a year in my
hangar. I need it for my 125 watt preheater if I'm taking an early-morning
flight in the winter, and will use it for a .25A trickle charger if I've let
the aircraft sit for more than a week or two.

The problem is that my T-hangar doesn't have power. One of the other hangar
renters had electrical service pulled to his hangar, and sublets 15A
breakers for $15/month = $180/year, which is a bit much for me, considering
my needs are for a dollar or so of electricity a year.

Any suggestions other than either buying a small generator or paying the
$15/month?

I'm asking because the "power guy" complained last week when I ran a
dropcord to a neighboring hangar for an hour last week to run the trickle
charger...

KB


Kyle,

Where are you located and do you have an unobstructed southern exposure for
solar panels? Could you south facing solar panels on the roof of your
hangar?

In Georgia, to set up a reliable solar system that would meet the
requirements you outlined above will probably cost about $500. Maintenance
would be to check the battery water at appropriate intervals (a few times a
year).

It might be less expensive to run a line from your neighbor's hangar, and
pay him a few bucks a month.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

I would hesitate to recommend solar panels and batteries for the
purpose of generating heat - but it is certainly do-able. Were I to
decide to go this route I would find some sort
of a DC heating element to use - thus avoiding the expense and
conversion loss of running an inverter. If your winter flying is
infrequent you could figure your recharge time to be a week or more,
and thus size your solar array accordingly (and save upfront cost in
the process). I have had great success with using solar battery
maintainers in my airplane and also in a seldom-used vehicle.

This past winter I tried a different approach to preheat. AC was
available - with a long extension cord - and I had a couple of the
"cube" style ceramic heaters laying around. I picked up a couple of
dryer duct flanges and duct taped these to the business ends of the
cubes. Then I took an 8' dryer hose, cut it in half and attached the
halves to the cubes.
Feeding the heat to the engine by way of the cowl flap openings, I let
this rig run for half an hour with temperatures in the 20s. I have no
idea what the engine temperature was after this treatment, but it did
start immediately - just like in warm weather. If no AC is available,
one could power heaters of this sort with an inverter in a car. It
would take
a large one - 3 KW or so for a pair running on high. It occurred to me
that a couple of
cheap ($10 at Walmart) hair dryers might do the job just as well (the
wattage is similar - about 1500) - but I haven't had the opportunity to
try it.

David Johnson

On 4 Jul 2006 21:04:12 -0700, wrote:

I would hesitate to recommend solar panels and batteries for the
purpose of generating heat - but it is certainly do-able. Were I to
decide to go this route I would find some sort
of a DC heating element to use - thus avoiding the expense and
conversion loss of running an inverter.

For a building, I would definitely agree. For an a/c block heater, though,
one's choices are more limited. And 125W is a fairly modest load.

The issue, though, is whether the OP wants to jury-rig a heater for his
a/c, that might be only usable with a DC supply, versus perhaps he has
something already installed, which can be used at other airports, with an
AC source.

He'd really have to do some cost comparisons to determine the most useful
and economical method.

Since he already has a heater, the question would be whether purchasing or
fabricating a second heater, which would only be used in his hangar, and a
controller to avoid overcharging his a/c battery (he already has a charger)
would be more or less expensive than a small inverter and perhaps slightly
more panel than might be required without an inverter.

I still think that the economics would favor a few bucks a month to his
neighbor, and a long extension cord :-).
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

writes:

Were I to
decide to go this route I would find some sort
of a DC heating element

What kind of heating element *doesn't* work on DC?

--kyler

On Wed, 5 Jul 2006 08:06:44 -0400, Kyler Laird
wrote:

writes:

Were I to
decide to go this route I would find some sort
of a DC heating element

What kind of heating element *doesn't* work on DC?

--kyler

Obviously, any resistive load will heat up if you put DC voltage to it.

But now you've got me thinking.

What are the design considerations for converting a heating element that
has been designed to function on 120VAC to 12VDC?

For example, I have a TANIS system in my a/c which draws about 375W @
120VAC.

It consists of four heated intake bolts, and a heated oil screen. It works
very well and heats the entire engine to 75-100°F on below zero F days
(with a cover).

I'd guess, as a minimum, I'd have to rewire everything to handle ten times
the current, depending on whether or not the 120V wiring is oversized, or
not. That might (or might not) add sufficient weight to have to do a new
W&B (A&P and logbook entry required). Obviously have to change the
connectors, too. How simple would it be to attach the larger wire to the
bolts and engine oil screen?

Will the heating elements handle a continuous (DC) as opposed to an
intermittent (AC) current? Or will I need some kind of
controller/thermostat?

I'd also want to retain the ability to run on AC, so I'd need some kind of
additional connector -- probably paralleled with the AC connector.

What about the AC neutral/ground? If that gets upset in the rewiring, I'll
wind up blowing GFCI breakers when I use AC.

??
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

Ron Rosenfeld writes:

Obviously, any resistive load will heat up if you put DC voltage to it.

But now you've got me thinking.

What are the design considerations for converting a heating element that
has been designed to function on 120VAC to 12VDC?

Note that I wasn't suggesting using 12VDC. I was thinking in terms of
an equivalent voltage DC. That would not require any changes to your
installed system.

I'm really not even suggesting using DC; I was just pointing out that
the heating elements can handle it. Nine 12V batteries in series should
give approximately the equivalent power to a resistive load as 120VAC.
It could be done but it'd be a pain.

I think you'd be happier using a special-purpose (cheap,
high-efficiency) inverter on a single 12V battery. You could have a
noisy 400 Hz inverter and it would be perfectly fine for your heating
elements.

....or you could just buy a decent general-purpose inverter and use it
for powering a video projector for late-night drive-in movies at the
hangar when the weather is nice.

--kyler

Ron Rosenfeld wrote:
: What are the design considerations for converting a heating element that
: has been designed to function on 120VAC to 12VDC?

: For example, I have a TANIS system in my a/c which draws about 375W @
: 120VAC.

You wouldn't convert it. You'd just hook it up to ~125 VDC. It will work
great. You may have trouble if it has an electronic thermostat (SCR/TRIAC)
because these require the reversals of the AC voltage to stop conducting
(you can turn on a TRIAC with DC across it, but you have to interrupt
the current flowing to shut it off).
--
Aaron C.