Low Voltage DC Heating Blanket Can Keep You Warm When the Power is Out.


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Doctor Aaronson, Omaha, Nebraska's OTHER Oracle. Dr. Michael Aaronson is a kidney physician specializing in Nephrology and hypertension.

heating blanket low voltage dc warms freezing cold home magnify

SoftHeat Luxury, low-voltage, heating blanket plugged into a Duracell Powerpack 600 with a Kill-a-Watt meter to determine the amount of watts and volts that are required to use the product to heat the room.

I'm so happy to offer yet another approach to stay warm when the power goes out. Today we will utilize the concept of radiant heat, using a low-voltage warming blanket that connects to a battery-powered, electrical generator to keep you and your family comfortable for a period of time during an emergency. Let's get started.

After getting burned in the past believing theories that may or may not be true, I paradigm shifted my approach on life in general from acting on theory to trying a concept to see if it works and then, only if proven, taking action. Said another way, as you will see, you want to make sure something that you think will work, will indeed work. Because if you don't confirm ahead of time, you will either get burned or be left out in the cold...

As pertains to this blog: the theory I had was that I could generate enough heat for a short period of time (3-6 hours) using a number of different approaches so that my family would be warm enough when the power goes out to stay in the house until the power went back on, avoiding the hotel. I started the experiment by plugging in a ceramic space heater to my back up battery power source to see if I could generate some heat.

ceramic space heater 1500 wattduracell powerpack

"All of the rumors keeping me grounded. I never said. I never said that they were completely unfounded" -- MORRISSEY

No heat was produced because the ceramic space heater requires 1500 watts of energy to work. The requirement is way more power than my electrical generator can produce. My generator can provide a maximum of 450 watts of continuous current for a very short period of time. Perhaps there was another option? After weeks of research, I found, found, found the scientific principles that explain why radiant floor heating works. I wondered if I might successfully apply these principles to my predicament: to warm the house when the power is out, and electricity from the wall is not available.

Let's get on the same page. As shown in the figure below, you can see that it takes less heat to warm a room using radiant as opposed to forced air heating. In forced air heating, the heat that is generated has to travel a long way to reach its target which requires time, more energy, and higher temperatures. On the other hand, radiant floor heat doesn't have to travel far to reach its target. Therefore this type of heat, distributed evenly at ground level, requires less energy in order to get the work done. From Wikipedia (from my offline Wikipedia on Android -- read more): "The internal air temperature for radiant heated buildings may be lower than for a conventionally heated building to achieve the same level of body comfort, when adjusted so the perceived temperature is actually the same."

why it takes less heat to heat a room using radiant as opposed to forced air heating
An explanation of why it takes less heat to warm a room using radiant as opposed to forced air heating.

My charge: to prove to the world the concept that I could power a heat blanket with a backup battery to create the radiant heating environment shown above. I proceeded to plug my Sunbeam electric blanket into the power source and waited to see what happened. After a short period of time I felt the heat from the floor. Great Scott! It worked! I shouldn't have been surprised, though. Since, my powerpack has a continuous power rating of 450 watts, it can handle the 180 watts required to run the heat blanket -- much less than the 1500 watts required to power a ceramic space heater.

What did surprise me was how quickly the battery drained. Using the Kill a Watt (see related by clicking on the red, down arrow above), I noted that the particular blanket I was using (which is phenomenal when there is electricity readily available) required 180 watts to run. As you will learn, using the table provided below, with these parameters, my particular Sunbeam electric blanket will generate radiant heat for less than 1 hour -- not enough time to allow the power company to restore power in times of real emergencies, such as winter storms, tornadoes, or hurricanes.

So I searched for a more functional option to give me more time and found a blanket that worked at a low wattage. This product might be the cure to my problem! A low voltage-requiring blanket might provide enough warmth for a long-enough time to effectively keep me, Baby Aaronson, and the rest of the family warm and cozy. Perhaps we can weather the storm!

It turns out that there are different types of low wattage-requiring heat blankets available on the market. You can purchase both AC and DC powered options. It's complicated, so I will get to the point: I went with the AC low wattage option, namely the SoftHeat blanket, so I could use the blanket all the time and get the most utility out of it.

AC blankets plug into the wall and come with a standard plug. DC blankets are good for cold cars and usually come with a car adapter. I wanted a plug in version so went with AC. Therefore, the SoftHeat electric blanket met my requirements. That said, please note: my specific set up starts with DC power generated from the Duracell battery. That power is converted into AC power via an inverter located inside of the machine. The blanket plugs into one of the available AC outlets located on the Duracell battery. Next, electronics in the blanket takes that AC power and converts it back to DC power which runs the blanket at low voltage.

The electric blanket controller converts the AC power to DC to allow for low wattage output to the blanket:

a low voltage heating blanket requires 14 to 18 volts to heat

My low voltage heating blanket requires 14 to 18 watts to heat. Please note that if you purchase the King-sized blanket you will use 2 controllers which will require 36 watts to heat (18 + 18 = 36).

Here is a close-up view of the contraption working splendidly:

close up view of a working unit duracell battery powered low voltage ac warming soft heat blanket

The electric blanket is spread out on the floor. It is a king size and has 2 controllers. The controllers are plugged into the AC outlets located on the Duracell battery. The blanket is heating the room through radiant heat. The electric blanket is powered by the battery. How long will it work before the battery runs out?

In order to get a feel for how long heat will emanate from the floorboards, consider the following table which describes how many watts it takes to run a particular appliance and the estimated run time using the Duracell battery shown above.

Table: AC Appliances and Run Times using the Duracell Powerpack 600
Run time
Clock radio
26 hours
Fluorescent Work light
13 hours
Portable DVD player
12 hours
Softheat Heated blanket 1 controller
about 5 hours
Softheat Heated blanket 2 controllers
about 3 to 3 1/2 hours
Laptop computer
3.5 hours
Portable cooler
2.5 hours
Table lamp with incandescent bulb
3.5 hours

Must not miss take home point: My last blog demonstrated the use of human-powered energy generation, via a hand crank or a bicycle generator, to create between 12-50 watts of light and heat using a light bulb. I explained why it works. If you are tired and do not want to exercise to create heat, another method to create emergency heat is to connect the Duracell battery to either an incandescent bulb or an infrared bulb to create light and heat. As shown above, a 40 watt bulb will produce approximately 3.5 hours of warm heat.

infrared bulbincandescent bulblfluorescent bulb
Infrared bulbs produce more heat than incandescent bulbs which produce more heat than fluorescent lights which produce more heat than LEDs.

Another important point: there are many backup electrical power options. I chose the Duracell for a few reasons. First the price was right compared with the other options -- that at the end of the day are probably better. I didn't know if my theory was going to work, and I already have a jump starter. So I went with the product I felt was most likely going to work (which is described in great detail following the link in the related section up above), because I didn't want to fail and lose hundred of dollars. Capice?

Also, the Duracell has the ability to connect to my solar panels. This feature was important to me because when the power goes out, a grid tie will not help you -- it will not work. Once the storm settles, the sun will come out, and solar power is a method to provide energy while you wait for the power to come back on. (Read more about my cost effective approach to saving money on your electrical bill by reading: How to Cost-effectively Connect a Monocrystalline Solar Panel to a Grid Tie Power Inverter and Generate Free Electrical Energy.)

duracell powerpack 600 has an input for solar power
Duracell Powerpack 600 has an input for solar power.

That said, there are many options out there when it comes to purchasing back-up energy power. You might want a battery back up that provides more juice for a longer period time. Perhaps you want to buy a real portable generator that is gasoline powered? Just make sure you don't use a gasoline powered or propane powered generator inside the house. Remember, the goal here is to stay alive. ;-)

"Warm lights from the grand houses blind me" -- MORRISSEY.

Conclusion: radiant heat affords you the opportunity to remain in your home longer than you otherwise would be able to. When considering the cost of staying at a hotel for the night, this proven concept may be worth trying. Enjoy!





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