BOATYARD
cost? Zero, unless you factor in the price of
the soap you use for periodic cleanings.
Portable coolers, by the way, come in
sizes from too heavy to carry easily, to
small enough to sling over your shoulder.
If you have an ice chest on board, there’s
a portable cooler that will fi t in its place;
if you want a miniature box to keep near
the helm, there’s one for that too. Most
refrigerator manufacturers sell portables;
the Norcold NRF 30 refrigerator/freezer
(thetford.com) is a typical full-featured
smaller (8-gallon) model, with an electronic
control panel, a stainless-steel interior, and
user-adjustable battery protection. It weighs
40 pounds empty and draws about 4 amps
at 12 volts. Cost? About $600. Dometic and
Isotherm sell similar products.ICE IS NICE
And fi nally, consider this. Mechanical
refrigeration is cool, but what’s wrong withice? Most people don’t spend weeks, or even
days, on board. If your cruising time tends
to be limited, why hassle with electric re-
frigeration, especially when there’s probably
a reefer in the galley anyway? Put food that
has to be kept cold and dry there, but dump
snacks and drinks for the on-deck crew in
an ice chest. A good Igloo (igloocoolers.com)
or Yeti (yeti.com) will do the trick, even in
the summer, with the added advantage of a
supply of ice cubes for drinks. I’m an Igloo
man myself, but Yeti ice chests supposedly
have the advantage of being bear-proof,
which I’m told can come in handy at times.
For non-boaters, of course.How Much Juice?
When the engine’s running or the shore
cord’s plugged in, who cares how much
electricity the reefer needs to stay cold? The
alternator or charger takes care of that. But
when swinging at anchor for any length of
time, running off the batteries, power usage
is more critical. Nothing sucks up amps like a12-volt refrigerator with a compressor that’s
working overtime. But how much power does
a reefer really need?
Experts estimate a marine refrigerator’s
compressor typically runs about 40 percent
of the time. I think 50 percent’s a better
estimate on a hot summer day with people
opening the door repeatedly, and it’s safer
to over-estimate power drain, anyway. Con-
sult the manual for your reefer to discover
how much power it uses; some manufactur-
ers specify watts, so divide by voltage to
get amps. (Most 12-volt refrigerators draw
between four and six amps.) Four hours at
anchor with the engine shut down means
two hours of compressor operation, and
a battery drain of 12 amps or so, over and
above the baseline drain. Anchor overnight,
say for 12 hours, and you’ll use roughly 36
amps. At any rate, keeping an eye on battery
voltage will head off power issues before
they become overly dramatic, and always
switch to one bank of batteries when there’s
no recharging taking place. That way you’ll
have plenty of juice left to fi re up the en-
gines when you need to go ashore for more
refreshments.810 Oregon Avenue, Ste. F - Linthicum, MD 21090 - Ph. 410-636-5991 - Fax 410-636-5995
WORLD-CLASS NAUTICAL EQUIPMENT