>Henry
>
>Dont hit us up the side of the head with something like that and leave us
>standing here what should we be doing about power
drains.(g) Besides the
>reefer what are you referring to?
>
OK. You asked for it!
First, for all lighting fixtures - even if you are going to keep the
original incandescents, make certain that there is no corrosion in the
sockets, switches, and wire connections. That's a requirement based on the
age of the vehicle and not the original configuration. When it comes to
lighting, you lose lumens (amount of light) at about a square law rate:
half the voltage means one quarter the light output or incandescents. In
addition, the light shifts in spectrum towards red. The wire connections,
especially grounds on the GMC, are prone to corrosion which translates into
added resistance. I measured 3+ volt drops in several wire runs to lights
before I started cleaning things. With this much drop you get about half
the lumens so you end up turning on more lights.
Some of the wiring is too small for the length of the wire plus return
path. This translates into more voltage drop and lower light output. I've
considered replacing some of the 12V lighting wires but haven't done so yet.
The fridge is the biggest power drain issue in the original configuration.
Unless you run the genset a lot, the fridge will suck down the batteries
pretty rapidly. And, the 12V feed is too small for the load. Propane is a
good thing for battery life.
On the charging side, the house battery cables are too small as are the
engine battery cables. Both result in a loss of efficiency due to voltage
drop. They'll work, but it will take longer to charge batteries to an
acceptable level. The wire from the alternator to the isolation block is
too small. Try grabbing the wire when the alternator is putting out near
maximum current - it's hot. The diode isolator also dissipates a fair
amount of heat when loaded. A better solution from power efficiency is to
use latching relays or manual switches - no significant voltage and no
holding current.
There's been a lot of discussion on the list about chargers, so I won't
beat that one. ;>
Heating and cooling are two big power hogs. Assuming that you're not using
the A/C:
The original power vents are horrible air movers for their amperage. Modern
vents are more efficient and quiter for the volume of air moved. Be
cautious of multispeed vents since some of them use a series of resistors
to divide the voltage to obtain lower speeds. Best is to look for an
electronic speed control that uses pulse width modulation ( I haven't
started down that path yet). I find that having a rain sensor vent means
that I can leave the vents open during the day and not worry about water
getting in. By keeping ventilation going while we're away, we never have as
much heat to eliminate when we get back. (And you don't have to have the
vents running for benfit).
Good window shades are one of the best power reduction sources around.
Judicious control of shade position can heat or cool the coach to a good
degree. When we boondock for extended periods we put the reflective bubble
insulation in the sun-facing windows to keep heat out. Good window tinting
will do some of the same while letting visible light in.
Heating relies on a lot of power to run the fans. Good weather striping,
seals, and window seals all help. Caulk any coach body leaks to prevent air
infiltration. Make certain that interior vents can be sealed (but leave the
required ones open). Improve ceiling insulation, floors and walls. Add
cellular shades to windows to provide more insulation.
Then there are the personal management items like turn off lights when not
in use, use only as many lights as you need, etc. install some task
lighting to brighten specific areas.
As one way of relieving the burden of our old refer, we put frozen gallon
jugs of water in the fridge. We used the water as it thawed. We also use
the fresh water tank for washing and flushing only. Drinking water is
carried in 2.5 gal plastic containers from the supermarket. We don't run
the pump much that way.
I'm sure that I've missed some, but it's a start.
Henry
Henry Davis Consulting, Inc / new product consulting
PO Box 1270 / product readiness reviews
Soquel, Ca 95073 / IP reviews
ph: (408) 462-5199 / full service marketing
fax: (408) 462-5198
http://www.henry-davis.com/ http://www.henry-davis.com
