safe cooking - Page 23 - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance
 Not a Member? 


Like Tree96Likes
Reply
 
LinkBack Thread Tools
  #221  
Old 04-01-2014
Puddin'_Tain's Avatar
Don't call me a "senior"!
 
Join Date: Feb 2014
Posts: 550
Thanks: 0
Thanked 21 Times in 18 Posts
Rep Power: 1
Puddin'_Tain is on a distinguished road
Re: safe cooking

Quote:
Originally Posted by barefootnavigator View Post
Its proven fact that LED causes brain cancer, Sorry
Gotta reference?
__________________
Typed on my Underwood Finger-Flight Champion portable typewriter (in triplicate, using carbon paper), sent to my basement laboratory via pneumatic tubes, transcribed by Minions on a Commodore 64 (complete with 5 1/4" single-sided floppy), and uploaded to the Internets via 14.4 kbit/s modem. Ain't modern technology grand?
Reply With Quote Share with Facebook
  #222  
Old 04-01-2014
mitiempo's Avatar
Senior Member
 
Join Date: Sep 2008
Location: Victoria B.C. Canada
Posts: 7,070
Thanks: 0
Thanked 68 Times in 59 Posts
Rep Power: 7
mitiempo will become famous soon enough mitiempo will become famous soon enough
Re: safe cooking

Quote:
Originally Posted by SVAuspicious View Post
Units are important. There are a couple of people on this thread with near saintly patience. Kudos to Puddin' Tain and GeorgeB who have been getting it right.

Units are important. If you are using units like amps/hr (or /min or /sec) you don't understand. If you use amps to measure power (W, kW) or energy (Ws, Wh, kWh, or (unfortunately since it adds voltage dependance) Ah) you don't understand. Carry the unit terms through your calculations and you'll see you the error of your ways. This is Jr High School algebra and you should understand it.

I don't intend to offend anyone directly. I hope to help you understand just how important this material is, and that if you get the units straight you will be an electrical rock star.



This is a great example. Lets walk through it.

First remember that watts are a measure of power that is NOT voltage dependent. That makes them great for dealing with voltage conversions that happen at inverters or battery chargers. Let's use my little Tappan microwave instead of the undefined one above. It is sold as a 600W microwave because that is the output of the microwave transmitter in the oven. If you read the label on the back you'll see it draws a maximum of 850 watts; the difference is due to the efficiency of the transmitter, losses in the power supply, and the control board, clock, etc. So we use 850 watts.

Actual RMS AC voltage (what you read on a volt meter) for US spec appliances should be between 117 and 120 VAC at 60 Hz (Hertz is just the frequency of the alternating cycle (AC) power). Let's use 120 to keep things simple.

850 watts (volt∑amperes neglecting power factor which isn't relevant until we talk about refrigerators, air conditioners, or other device with significant rotating loads) / 120 volts = 7 amps ON THE AC CIRCUIT supplied by the inverter. We'll go back to watts to work our way through the voltage conversion in the inverter since it is voltage independent. My Mastervolt 2kW inverter has an efficiency of 95% - actually pretty decent. 850 watts on the AC side turns into 850 watts/0.95 = 895 watts on the DC side. If my batteries are fully charged and providing 13.6 VDC the microwave will draw 895 watts / 13.6 V = 66 amps. That's a lot of amps. If I heat up a casserole for 8 minutes I'll use 66 amps * 8 minutes / 60 minutes/hr = 8.8 Ah from my 675 Ah battery bank, about 1.3% of capacity. Not bad at all.

Lets look at a spaghetti dinner on an induction cooktop. Assume 3 minutes at 1500 watts to boil the pasta water and 11 minutes to cook the pasta at a lower setting - say 600 watts. We also heat canned spaghetti sauce (I'm making this simple so we don't have to saute meat and mirepoix, and sauce and paste, yadayadayada) at about 300 watts for the same total time.

3 min * 1500 W + 11 min * 600 W + 14 min * 300 W = 15300 W∑min (aren't watts wonderful?)
Through the inverter 15300 W∑min/.95 efficiency = 16105 W∑min
Again with fully charged batteries that means 16105 W∑min / 13.6 V / 60 min/hr = 20 Ah
Not the end of the world, but that does mean that if spaghetti is representative of a cooked meal and you make two a day aboard and that if refrigeration draws about the same 20 Ah you could cook with propane and have two big refrigerators and a separate freezer and come out ahead. If that's a good trade-off for you, fine - just make the decision with your eyes open and don't kid yourself that there is some magic efficiency changing the rules of physics.

Now one watt is roughly 3.4 BTUs, so a 1500 W induction hob is equivalent to a 5100 BTU propane stove burner. It can't be different. Force 10 and Eno propane cookers (for example) have large burners that run between 8000 and 8500 BTUs. The smaller burners hover around 3400 BTU. So in our spaghetti example above, the propane stove will boil the water faster than the induction hob, but that only reduces the initial 3 minutes. It isn't relevant to heating the sauce or cooking the pasta at reduced heat.

In fairness, most propane cookers have an electrical solenoid in the propane locker that draws a surprising amount of power. Many draw about 1 A the entire time they are switched on. So our spaghetti dinner on a propane cooker consumes 14 min * 1 A / 60 min/hr = 0.23 Ah. Not much, but it should be counted.

All the efficiency claims of induction are relative to electrical resistance heating, not gas.

Exercise: look up and understand current (amps), power (W), and energy (Wh, Ah, BTU).
Nothing like keeping it simple.

1000 watts AC out of an inverter takes 100 amps DC - a bit conservative but easier numbers to use. 1000 watts for one hour out of the inverter consumes 100 AH from the batteries. That is really all you need to know.

Anonymous
christian.hess likes this.
__________________
Brian
Living aboard in Victoria Harbour
Reply With Quote Share with Facebook
  #223  
Old 04-01-2014
barefootnavigator's Avatar
Senior Member
 
Join Date: Mar 2012
Location: Salish Sea
Posts: 555
Thanks: 22
Thanked 21 Times in 21 Posts
Rep Power: 3
barefootnavigator is on a distinguished road
Re: safe cooking

Quote:
Originally Posted by Puddin'_Tain View Post
Gotta reference?
I'm really sorry, I was just teasing, i shouldn't joke about that ****.
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #224  
Old 04-01-2014
Puddin'_Tain's Avatar
Don't call me a "senior"!
 
Join Date: Feb 2014
Posts: 550
Thanks: 0
Thanked 21 Times in 18 Posts
Rep Power: 1
Puddin'_Tain is on a distinguished road
Re: safe cooking

Hmmm...alcohol stoves can't cook pasta? I must have imagined all those pasta dinners and lunches I've cooked on my boat.
__________________
Typed on my Underwood Finger-Flight Champion portable typewriter (in triplicate, using carbon paper), sent to my basement laboratory via pneumatic tubes, transcribed by Minions on a Commodore 64 (complete with 5 1/4" single-sided floppy), and uploaded to the Internets via 14.4 kbit/s modem. Ain't modern technology grand?
Reply With Quote Share with Facebook
  #225  
Old 04-01-2014
Puddin'_Tain's Avatar
Don't call me a "senior"!
 
Join Date: Feb 2014
Posts: 550
Thanks: 0
Thanked 21 Times in 18 Posts
Rep Power: 1
Puddin'_Tain is on a distinguished road
Re: safe cooking

Quote:
Originally Posted by barefootnavigator View Post
I'm really sorry, I was just teasing, i shouldn't joke about that ****.
I thought so. But ya' never know what wacky things people will believe.
captain jack likes this.
__________________
Typed on my Underwood Finger-Flight Champion portable typewriter (in triplicate, using carbon paper), sent to my basement laboratory via pneumatic tubes, transcribed by Minions on a Commodore 64 (complete with 5 1/4" single-sided floppy), and uploaded to the Internets via 14.4 kbit/s modem. Ain't modern technology grand?
Reply With Quote Share with Facebook
  #226  
Old 04-01-2014
barefootnavigator's Avatar
Senior Member
 
Join Date: Mar 2012
Location: Salish Sea
Posts: 555
Thanks: 22
Thanked 21 Times in 21 Posts
Rep Power: 3
barefootnavigator is on a distinguished road
Re: safe cooking

Quote:
Originally Posted by Puddin'_Tain View Post
Hmmm...alcohol stoves can't cook pasta? I must have imagined all those pasta dinners and lunches I've cooked on my boat.
Alcohol stove + pressure cooker =YUMMI
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #227  
Old 04-01-2014
Senior Member
 
Join Date: Jan 2009
Location: Deer Harbor, Washington
Posts: 212
Thanks: 0
Thanked 9 Times in 9 Posts
Rep Power: 6
mitchbrown is on a distinguished road
Re: safe cooking

Quote:
Originally Posted by hellosailor View Post
Coal? No good for boats, too hard to get good coal in most of the developed world, and too easy to have a monoxide problem.

But speaking of spaghetti, that's a classic "ain't gonna happen" on a 6800btu burner. Can't boil a big pot of water on that. Although, most of us were taught how to cook pasta the rich way, with a big pot of rolling boiling water. If you just bring the water to a boil, and then shut the burner and come back to stir the pasta every few minutes, it cooks up just fine. May take 20 minutes instead of 10, but it cooks just fine without the need for copious amounts of boiling water. Great way to save fuel, whatever kind it is.
FYI copied these specs from a force 10 propane marine stove.

3,400 BTUs per small top burner

8,200 BTUs per large top burner

5,100 BTUs oven burner
5,500 BTU Broiler

So you can see that the Origo alcohol stoves burners are right inline for marine stoves

Sure Marine Service, Inc. | Force10
olson34 likes this.
Reply With Quote Share with Facebook
  #228  
Old 04-01-2014
MedSailor's Avatar
Closet Powerboater
 
Join Date: Mar 2008
Location: Anacortes PNW
Posts: 2,470
Thanks: 75
Thanked 51 Times in 43 Posts
Rep Power: 7
MedSailor is on a distinguished road
Re: safe cooking

Propane = risk of boom.

CNG = risk that you can't find a fill station... or boom.

Alcohol = risk of burn (or blindness if you drink it)

Kerosene = risk of CO poisoning.

Electric and genset = risk of being murdered by your neighbor in a quiet anchorage

Wood = risk of setting fire to your boat

Diesel = risk of wood and kerosene combined

fission = risk of cancer

fusion = risk of the CIA murdering your for your technology

cold food = risk of suicide

Everything has risk. You make your choices, you CHOOSE WHICH RISK you prefer and go with it. If propane were really all that dangerous don't you think that the drunken idiots all over America that are operating poorly maintained, made in China BBQs would be blowing themselves up all time? Yet somehow they're not....

MedSailor
__________________

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


I have a sauna on my boat, therefore I win.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #229  
Old 04-02-2014
captain jack's Avatar
Senior Member
 
Join Date: May 2013
Location: frederick, md
Posts: 1,222
Thanks: 78
Thanked 38 Times in 34 Posts
Rep Power: 2
captain jack is on a distinguished road
Re: safe cooking

Quote:
Originally Posted by barefootnavigator View Post
Not me, I shut my cell phone off two years ago. But then there is wifi Dman!


i suppose, you could always start wearing a tin foil beanie to keep all the bad stuff out of your head.
__________________
The only rules that really matter are these: what a man can do and what a man can't do.---Captain Jack Sparrow


1971 Cal 27

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #230  
Old 04-02-2014
captain jack's Avatar
Senior Member
 
Join Date: May 2013
Location: frederick, md
Posts: 1,222
Thanks: 78
Thanked 38 Times in 34 Posts
Rep Power: 2
captain jack is on a distinguished road
Re: safe cooking

Quote:
Originally Posted by barefootnavigator View Post
Alcohol stove + pressure cooker =YUMMI
you've eaten alcohol stoves and pressure cookers?! that can't be easy on your teeth!
Minnewaska likes this.
__________________
The only rules that really matter are these: what a man can do and what a man can't do.---Captain Jack Sparrow


1971 Cal 27

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Solar cooking... travlineasy General Discussion (sailing related) 4 01-30-2013 03:52 PM
Solar cooking bwalker42 Provisioning 24 10-04-2012 12:51 PM
Cooking in a gale..... MedSailor Gear & Maintenance 8 02-27-2012 12:11 PM
Looking for a Cooking Author socaleditor Provisioning 1 02-06-2005 03:52 PM
cooking duffyM Provisioning 10 09-04-2003 04:28 PM


All times are GMT -4. The time now is 09:27 PM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.