# Thread: Heater on the Cheap

1. ## Heater on the Cheap

I've got a 1500 watt inverter in the cabin of the boat. I still haven't gotten a heater yet for the boat and came up with this. Not planning on running it all the time, just take the chill off when needed. What do you guys think?

http://www.costco.com/Browse/Product...h&lang=en-US&N
r=P_CatalogName:BC&Sp=S&N=5000043&whse=BC&Dx=mode+ matchallpartial&Ntk=Text_Search&Dr=P_CatalogName:B C&Ne=4000000&D=HEATER&Ntt=HEATER&No=0&Ntx=mode+mat challpartial&Nty=1&topnav=&s=1

2. I think that this would draw some serious amps. Any idea what it draws?

3. When you ask the question I thought it would be 65 amps. When I did the math it was over 80 amps.

4. Originally Posted by spoiled one
I think that this would draw some serious amps. Any idea what it draws?
120 volts X 8.33 amps = 1000 watts

5. just buy another starting battery when you pick it up at costco, i think your going to need it.

6. You are correct if you are talking about the output current from the inverter. I assume spoiled one was talking about the battery current at 12.6 v dc not 120v ac.

7. I currently have two Alaskan Gold Deep Cycle Batteries. If I ran it let's say 15 minutes every hour, would I be able to manage.? I'm not savy with electronic issues. I have been using a hot plate to cook, hot pot for drinks and soups/ Ramen with no issues.

8. The formula for Amps is Watts divided by Volts.

In this case we know that the heater uses 120 volts and 1000 watts so we divide 1000 into 120 and see that it will draw

8.33333333 amps.

If I'm correct.

I did a quick web search and most 1500 watt inverters are only rated at 750 watts continuous use, so your heater alone would exceed the limit.

It may however should work for limited use and your inverter should have a low power shut down.

9. Originally Posted by MacGyver
You are correct if you are talking about the output current from the inverter. I assume spoiled one was talking about the battery current at 12.6 v dc not 120v ac.
Yup, that is what I was asking. At 80 amps, that will put a real hurt on your batteries. I don't believe that your outboards will even be able to keep up with the drain. You would be better off going with a small kerosene heater or a mr. heater if you don't want to go with an espar or other forced air heater.

10. We use this little cabin heater from West marine

http://www.westmarine.com/webapp/wcs...classNum=50671

It is like 79 bucks and we have a 1500 watt inverter... It is basically a glorified hair dryer...

Seems like those little propane camping heaters would be inexpensive and produce the most heat for the buck..

M.

11. Originally Posted by stid2677
The formula for Amps is Watts divided by Volts.

In this case we know that the heater uses 120 volts and 1000 watts so we divide 1000 into 120 and see that it will draw

8.33333333 amps.

If I'm correct.

I did a quick web search and most 1500 watt inverters are only rated at 750 watts continuous use, so your heater alone would exceed the limit.

It may however should work for limited use and your inverter should have a low power shut down.
Your formula is correct, but you need to look at the entire scenario. If the heater requires 1000W from the inverter to operate, the inverter must be supplied with at least 1000W. If the inverter gets its power via 12V system, the current required to produce 1000W is over 80A, like others have suggested.

An electric heater is a poor choice for a boat. A group 27 or 31 battery just can't keep up, and adding a bunch of heavy batteries to increase your reserve capacity isn't really a great solution. Buying an expensive generator to run your inexpensive electric heater doesn't make a lot of sense either.

Originally Posted by spoiled one
You would be better off going with a small kerosene heater or a mr. heater if you don't want to go with an espar or other forced air heater.
This!

Combustion is always a much more efficient method of generating heat, and a much better choice on a boat where electrical power is limited.

12. Well it sounds like looking for an easy fix is just creating another problem. Like I said, I am not electrical savy. I already have a MYBuddy Heater but hate to use it as I prefer a dry heat. I usually leave the bulkhead door open or crack a window. Last time I was in Costco, I saw that little heater in use and I was quiet impressed with the heat it puts out for 1000 watts. I was just about to pull the trigger on a Toyo heater the NS 2800 two years ago but they stopped making them.

Thanks for the information from everyone.

13. Originally Posted by palasz
We use this little cabin heater from West marine

http://www.westmarine.com/webapp/wcs...classNum=50671

It is like 79 bucks and we have a 1500 watt inverter... It is basically a glorified hair dryer...

Seems like those little propane camping heaters would be inexpensive and produce the most heat for the buck..

M.
How does that little heater do on a 50 degree day if you keep the bulkhead door closed? Also, how long do you run it?

14. Chico, the West Marine heater still uses 600W on the lowest setting, and 1500W on high. It's still going to put a serious hurt on your batteries, drawing 50 Amps on low (which is like running a shrimp pot puller). You won't want to run it very long, and certainly not without the engine running at the same time.

I don't know what you're running for an outboard, but most do not have very big alternators for keeping batteries charged. Even the Yamaha 250s put out less than 30A for charging, and even then, they don't put out the full amount until you get the RPMs up to cruising speeds.

The math just doesn't work to give an electric heater any serious consideration, if you plan on running it off your boat's 12V system.

A propane heater offers you the best heat for the dollar, but it comes at the cost of increased moisture & condensation in the cabin. To get dry heat, you'll need to bump up to an Espar type diesel heater, and they are not cheap.

15. On the other hand, we carry a ~1500 watt electric heater, cost maybe \$30 at WalMart, for use when plugged into shore power at a marina on a cold/windy/rainy day. Works great for that, and it's almost totally silent.

16. I would NEVER put a radiant heater on a boat. Way too dangerous and too many fires on boats caused by them. Get one with a tip over switch. I've got a 800/1500 watt unit that takes the chill off OK. I run it either from shore power or my gen set if out.

17. Big Buddy works great never have to take off low.

18. I found this little deal yesterday. I think I may have room to mount on the wall where the outside of the bathroom, run the vent pipe thru the bathroom to provide a little heat and exhaust just about the bathroom door. I gotta get home first, take measurements and see if it would be a practicle mounting location and ensure I have the room. The price is awesome and totally affordable IMO. I could mount a fiberglass 10lb tank on the roof tucked in the corner under my radar arc where its protected and easy access and still be 1000 bucks. I think you guys definitely talked me out of attempting electric heat. Thanks for politely slapping sense into me. What do you guys think about this system?

http://www.boatownersworld.com/dicki...aces_p9000.htm

http://www.lpgastanks.com/propane-tanks/lc10

19. I know a couple of people that really like their Dickinson heaters and/or stoves. If you have room to mount one, they'll give you lots of warm, dry heat.

I don't know that I would pay big bucks for a fancy propane tank, though. I use the Blue Rhino exchange tanks from Wal-Mart and let them worry about keeping them filled and looking new.

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