Low energy heating

[FF]

For folks that worry about power consumption , an electric sheet will usually warm up the bunk in 10 or 15 min.

After that your bunk mate can take over.

AS we are Not Political correct , we call the sheet the "Fat Girls".

I read the folks in Alaska bring dogs into their igloo on very cold nights , more dogs on colder nights.

As the heat controller is 1 - 8 so the operating question is how many fat girls tonight?

A warm bed is a true luxury item!

 

[Wayfarer]

Forgive me please but, all these additional 12vt accessories we have been talking about require 12vt and X# of amps.

Just keep piling on the blankets and dont forget to put a blanket on top of the bottom sheet.
Dont really need electric mattress warmer or electric blanket. Snuggle close to your bunk mate. SMILE

With a face like mine, heated blankets are a lot easier to come by than bunk mates, lol.

Thanks to OCTed for suggesting the blanket a year ago. It's been a handy thing to have aboard on many occasions. The one I have doesn't seem to like my inverter though, unfortunately.

 

[O C Diver]

With a face like mine, heated blankets are a lot easier to come by than bunk mates, lol.

Thanks to OCTed for suggesting the blanket a year ago. It's been a handy thing to have aboard on many occasions. The one I have doesn't seem to like my inverter though, unfortunately.

Consider a very small stand alone pure sine wave inverter. Most electric blankets are under 300 watts and the consumption is intermittent depending on the controls. Probably can be had for under $100.

https://theinverterstore.com/product/300-watt-pure-sine-power-inverter/

Ted

 

[Wayfarer]

Consider a very small stand alone pure sine wave inverter. Most electric blankets are under 300 watts and the consumption is intermittent depending on the controls. Probably can be had for under $100.

https://theinverterstore.com/product/300-watt-pure-sine-power-inverter/

Ted

That's a good idea. I'd spent half a second thinking about upgrading my inverter/charger to a pure sine wave unit, but I hadn't considered adding a standalone inverter.

 

[Joe Pica]

Now that the chill has set in in N. Florida, time to start talking heat.

One way to heat yourself (literally) overnight on battery power is with a heated mattress pad. We have a queen pad with separate left-right controls.

I did an experiment last night and measured the power consumption of the pad. It was amazing to me. Outdoor temps got down to 38F. Morning inside the boat was 50F with no boat heat running. Double quilt/blankets on the bed.

The mattress pad ran for 10 hours at #1 (of 10) setting on left side and #3 (of 10) setting on the right side. The bed was downright COZY. The warmth from the pad was very noticeable. For all that time, we consumed a total of 120 watt-hours of energy at the inverter-supplied outlet. This is a mere 10Ah at 12V plus inverter inefficiency - say 11-12Ah total. For TEN hours of sleeping warmth! Wow!

Now,

• Yes, the boat is cold when you get up to pee.
• Yes, the boat is cold when you get up in the morning.
• You need an inverter.
• I would guess manufacturer's products vary - ours pulses the heat on and off over time to the setting selected.

But, WOW, an entire night of heat for 12 amp-hours!!! The comfort-to-power ratio is so good because the heat is applied directly to your body instead of heating up all the airspace in your cabin and having to have it make its way to you.

Just another option/data point for anyone who occasionally needs low power options on battery-only.

Cheers

Ray, You should run that new truck diesel heater and heat the entire boat. Then not chilled when getting up.

 

[rsn48]

Assuming 12 volts, that would also be drawing 10 amps, which over the course of an hour would be 10 amp-hours.

I haven't read all the responses but I may be late to the party. Speaking in terms of inverters, it takes energy to make energy, something that burns 10 amps will require more than 10 amps.

The one formula I have seen, and I'm not to sure how accurate it is, 183 amps to burn 1000 watts for one hour. So 100 watts for one hour would be 18.3 amps, taking into consideration the inverter needing to make energy from energy. This sounds a bit high to me.

 

[backinblue]

My take? 50 degrees inside the boat is ideal sleeping temp! Then again I live in New England, not FL!

 

[O C Diver]

Assuming 12 volts, that would also be drawing 10 amps, which over the course of an hour would be 10 amp-hours.

I haven't read all the responses but I may be late to the party. Speaking in terms of inverters, it takes energy to make energy, something that burns 10 amps will require more than 10 amps.

The one formula I have seen, and I'm not to sure how accurate it is, 183 amps to burn 1000 watts for one hour. So 100 watts for one hour would be 18.3 amps, taking into consideration the inverter needing to make energy from energy. This sounds a bit high to me.

Watts are watts regardless of voltage.

If you have a 150 watt electric blanket it will consme approximately:
150 watts ÷ 12 VDC = 12.5 amps
12.5 amps × 1.2 inverter conversion = 15 amps

Now the important part to understand is that almost nobody runs them at full output. Most blanket controls have a scale from 1 to 10 that's pretty close to the tenths of power consumed and wattage produced. At 10 you consuming 10 tenths of the power. At 1 you are consuming 1 tenth of the power (1.5 amps). Most evening I have it set on 1. In the mid 50s (degrees) it's 2. In the 40s it's 3.

#1 = 15 watts consuming 1.5 amps
#2 = 30 watts consuming 3 amps
#3 = 45 watts consuming 4.5 amps

So even with the inefficiency of the inverter conversion, the amperage consumption is very reasonable.

Ted

 

[caltexflanc]

We find a memory foam mattress topper below and a down comforter above to be just right, when we lived on board year around. When we go tent camping using our deluxe air mattress, just the comforter and flannel sheets is just as effective. Both solutions require zero energy consumption.

 

[Juggerknot]

Good observation. I'm certain my wife will be shopping for a heated mattress pad after reading this post! O C Diver has talked about using a electric blanket..are they the same?

No, they aren't interchangeable. The heated mattress pad apparently uses a more resilient type of heating element that resists the wear and tear of being slept on. I love mine, money in the bank when it gets chilly!

 

[boathealer]

Ray, You should run that new truck diesel heater and heat the entire boat. Then not chilled when getting up.

I still don't trust it enough yet to leave it on while sleeping.

Also, it really is only to take the chill off in the salon, there aren't enough BTU's for the whole boat.

?

 

[catalinajack]

Our typical temp at night is 46 - 50 degrees in Galesville, MD, ten miles south of Annapolis. Unless the outside temp goes below 20 degrees we do not turn on any sort of inside heating.. We have no need of an electric blanket. Our foam mattress and heavy down comforter is more than enough. In fact on moderately cold nights - outside temp 50 degrees or more - the comforter is too much. We are native New Englanders.

My take? 50 degrees inside the boat is ideal sleeping temp! Then again I live in New England, not FL!

 

[backinblue]

Our typical temp at night is 46 - 50 degrees in Galesville, MD, ten miles south of Annapolis. Unless the outside temp goes below 20 degrees we do not turn on any sort of inside heating.. We have no need of an electric blanket. Our foam mattress and heavy down comforter is more than enough. In fact on moderately cold nights - outside temp 50 degrees or more - the comforter is too much. We are native New Englanders.

Same here and agree with you. However, if you live in FL, 50 may seem unbearably cold!

 

[Daveo]

Here’s another “new” idea. I’ve been astounded at how well a standard hot water bottle works. Using the cheapo 2 liter Chinese imports from Amazon that come with a removable knit “sweater” around them. I ignore the warning labels and fill with boiling water. Still not too hot, presumably due to the sweater. Throw it in the bunk before retiring and it warms it up nicely. The most astounding thing, to me, is that it’s still warm eight hours later. Both a pleasure to go to bed with and a joy to wake up to! And, at less than ten bucks “https://www.amazon.com/AQUAPAPA-Gal...=1608082302&sprefix=Hotwater,aps,180&sr=8-26”, a cheap date. What could be better?

 

[O C Diver]

Here’s another “new” idea. I’ve been astounded at how well a standard hot water bottle works. Using the cheapo 2 liter Chinese imports from Amazon that come with a removable knit “sweater” around them. I ignore the warning labels and fill with boiling water. Still not too hot, presumably due to the sweater. Throw it in the bunk before retiring and it warms it up nicely. The most astounding thing, to me, is that it’s still warm eight hours later. Both a pleasure to go to bed with and a joy to wake up to! And, at less than ten bucks “https://www.amazon.com/AQUAPAPA-Gal...=1608082302&sprefix=Hotwater,aps,180&sr=8-26”, a cheap date. What could be better?

While I like the idea and give you points for thinking outside the box, on my boat, boiling water is generally done in the microwave or electric stove top. So really not a savings of battery power for me or firing up the generator.

Ted

 

[Goingplaces]

alternative to running HVAC

And of course this saves wear and tear and the much more expensive marine HAVC system!

 

[DDW]

Just saw the BedJet on another forum. Interesting concept, but the video is hilarious. Most entertaining marketing video I've seen in a long time.