Empathy List Archives

TS

Terry Sutton

Tue, May 13, 2003 3:23 AM

Shortly after purchasing our boat, the Norcold refrigerator died. This forces
us to make some decisions sooner than we were prepared to make them. I've
looked through the archives, but still have more questions, so here they are.

Is there any reason not to install a regular kitchen fridge? Assuming we
have inverters and sufficient battery capacity (and sufficient space), this
seems much more economical, given that I can get a 10 cu ft fridge for under
$300, compared to a 6 cu ft Norcold for ~$1000. Are there reasons not to do
this?
If using a regular kitchen fridge is OK, would it be feasible to use a
small appliance-specific inverter (like a Prowatt 1000 or 1750) just for the
fridge? We plan in the future to install a "whole boat" inverter, like a
Freedom Marine, but other items are consuming boat units rapidly, and if we
can delay that a while it would help. My home fridge is rated at 7 amps, so I
would think a slightly smaller unit would work on a 1000W inverter, or is
there a need to have a larger margin of load vs. capacity?
If the regular fridge idea is out, what are the pros & cons of a fridge
which runs on both 110V & 12V vs. one which is just 12V? I know, for
instance, that Novakool has units which run on 12V and 110/12, but the 110/12
is more expensive. Is there any reason not to run 12V all the time?

I think the answers to these questions will help me get my arms around the
situation, though it's also possible they'll just generate more questions.

Thanks,

Terry Sutton
Silver Satin
41' President

Shortly after purchasing our boat, the Norcold refrigerator died. This forces us to make some decisions sooner than we were prepared to make them. I've looked through the archives, but still have more questions, so here they are. 1) Is there any reason not to install a regular kitchen fridge? Assuming we have inverters and sufficient battery capacity (and sufficient space), this seems much more economical, given that I can get a 10 cu ft fridge for under $300, compared to a 6 cu ft Norcold for ~$1000. Are there reasons not to do this? 2) If using a regular kitchen fridge is OK, would it be feasible to use a small appliance-specific inverter (like a Prowatt 1000 or 1750) just for the fridge? We plan in the future to install a "whole boat" inverter, like a Freedom Marine, but other items are consuming boat units rapidly, and if we can delay that a while it would help. My home fridge is rated at 7 amps, so I would think a slightly smaller unit would work on a 1000W inverter, or is there a need to have a larger margin of load vs. capacity? 3) If the regular fridge idea is out, what are the pros & cons of a fridge which runs on both 110V & 12V vs. one which is just 12V? I know, for instance, that Novakool has units which run on 12V and 110/12, but the 110/12 is more expensive. Is there any reason not to run 12V all the time? I think the answers to these questions will help me get my arms around the situation, though it's also possible they'll just generate more questions. Thanks, Terry Sutton Silver Satin 41' President

TS

Terry Sutton

Tue, May 13, 2003 5:27 AM

After a couple of conversations and some more thinking, I realize that my
fridge questions were asked wrong. I realize now that, while my fridge at
home is rated at 7 amps, it's not consuming 7 amps on a constant basis. And
when I look at the Energy Guides on new refrigerators, they tend to estimate
300-500kWh/year of electricity consumption. If my math is right, that
averages out to ~0.35-0.55 amps on average. Norcold claims their fridge
consumes 0.7 amps at 110V. So I guess my new questions are:

Does anyone know if marine fridges are significantly more or less
efficient than land fridges? I'm looking for approximations. From my
calculations above, it looks like a land fridge might fall between the
energy consumption of a Norcold and a really efficient marine fridge
(Novakool?, Seafreeze?). Is this accurate?
If energy consumption is about the same, is there a reason a land fridge
is a bad idea? Is there something about marine fridges that makes them more
amenable to marine life?

Thanks,

Terry Sutton
Silver Satin
41' President

After a couple of conversations and some more thinking, I realize that my fridge questions were asked wrong. I realize now that, while my fridge at home is rated at 7 amps, it's not consuming 7 amps on a constant basis. And when I look at the Energy Guides on new refrigerators, they tend to estimate 300-500kWh/year of electricity consumption. If my math is right, that averages out to ~0.35-0.55 amps on average. Norcold claims their fridge consumes 0.7 amps at 110V. So I guess my new questions are: 1) Does anyone know if marine fridges are significantly more or less efficient than land fridges? I'm looking for approximations. From my calculations above, it looks like a land fridge might fall between the energy consumption of a Norcold and a really efficient marine fridge (Novakool?, Seafreeze?). Is this accurate? 2) If energy consumption is about the same, is there a reason a land fridge is a bad idea? Is there something about marine fridges that makes them more amenable to marine life? Thanks, Terry Sutton Silver Satin 41' President

CA

Captain Al Pilvinis

Tue, May 13, 2003 3:05 PM

Is there any reason not to install a regular kitchen fridge? Assuming we
have inverters and sufficient battery capacity (and sufficient space), this
seems much more economical, given that I can get a 10 cu ft fridge for under
$300, compared to a 6 cu ft Norcold for ~$1000. Are there reasons not to do
this?

---==========================
I've been using a 16 cu fridge for 20 years and stuck a holding plate in
the freezer and removed the ice maker because it heats up the freezer. This
rig runs on 3 hours worth of electricity a day and the ice cream stays well
frozen. With the plate we can pull the freezer down to 20 - 30 below 0 and
the fridge down to 26 in an hours run and the lettuce doesn't freeze. We
run an hour for breakfast, dinner, and before bed. At the same time we are
charging batts making hot water and AC if necessary. We take 6 heads of
lettuce when we go to the Bahamas we use a head a week and in the 6th week
we still have salads. Go for the 10 cu...............
.

Captain Al Pilvinis

"M/V Driftwood"--Prairie 47
2630 N.E. 41st Street
Lighthouse Point, Fl 33064-8064
Voice 954-941-2556 Fax 954 788-2666
Email yourcaptain@earthlink.net
Website http://home.earthlink.net/~yourcaptain

>1) Is there any reason not to install a regular kitchen fridge? Assuming we >have inverters and sufficient battery capacity (and sufficient space), this >seems much more economical, given that I can get a 10 cu ft fridge for under >$300, compared to a 6 cu ft Norcold for ~$1000. Are there reasons not to do >this? =========================================================== I've been using a 16 cu fridge for 20 years and stuck a holding plate in the freezer and removed the ice maker because it heats up the freezer. This rig runs on 3 hours worth of electricity a day and the ice cream stays well frozen. With the plate we can pull the freezer down to 20 - 30 below 0 and the fridge down to 26 in an hours run and the lettuce doesn't freeze. We run an hour for breakfast, dinner, and before bed. At the same time we are charging batts making hot water and AC if necessary. We take 6 heads of lettuce when we go to the Bahamas we use a head a week and in the 6th week we still have salads. Go for the 10 cu............... . Captain Al Pilvinis "M/V Driftwood"--Prairie 47 2630 N.E. 41st Street Lighthouse Point, Fl 33064-8064 Voice 954-941-2556 Fax 954 788-2666 Email yourcaptain@earthlink.net Website http://home.earthlink.net/~yourcaptain

D&

Don & Louise

Wed, May 14, 2003 2:08 AM

We had a regular kitchen fridge for 12 years of good service at the dock.
But traveling it just devoured the batteries. We have recently gotten a
Planet DC 9.6 cu ft. fridge, which runs only on batteries. Fantastic so
far. I am amazed at how little battery power it uses. No business
relationship - just a satisfied customer www.rparts.com is the link.

Louise
Aboard Caper leaving Gloucester Thursday for the Hudson - Great Loop

We had a regular kitchen fridge for 12 years of good service at the dock. But traveling it just devoured the batteries. We have recently gotten a Planet DC 9.6 cu ft. fridge, which runs only on batteries. Fantastic so far. I am amazed at how little battery power it uses. No business relationship - just a satisfied customer www.rparts.com is the link. Louise Aboard Caper leaving Gloucester Thursday for the Hudson - Great Loop

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TWL: Fridge questions