Cost of using EBH

I can't comment on your calculations, you probably know more than I. But I'd suggest you use a Kill A Watt meter so you can show your skeptic neighbors exactly how much electricity your EBH uses. It's also handy identifying other energy suckers.

 

Your math is correct, assuming your 120 volt block heater eats 2.5 amps (ie. 300 watts) and you have it plugged in 24 hours a day.

I'll second the idea of a KillaWatt meter to show them you are not pulling much. I'll agree it's strange to see a block heater in a heated garage, even in Alaska.

Perhaps they're afraid you'll get the "gas" for your car from the electric plug. MAny people may still think Hybrids need to be plugged in.The average person probably doesn't know about the PHEV plug-in conversions, but the reality is, you COULD be getting your "gas" from the plug. How would they know, other than suspiciously higher bills ?

 

The EBH is reported to draw about 400W, though the Kill-a-Watt will pin it down.

If it won't grow legs in the community garage, I suggest adding a timer to turn the heater on about 3 hours before your scheduled departure. The heater seems to reach a point of diminishing returns beyond that, and additional preheat time probably is not cost-effective. That might serve the added benefit of appeasing the neighbors.

As for whether it is worthwhile in a 60-degree garage, I vote "yes." Starting off with a block at up to 140F instead of 60F makes a significant difference in fuel economy for the first 5-10 minutes of driving.

 

Hi Kremtok,

First congrats for installing an EBH. I also park in a condo underground garage and wonder about your circumstances as to where were you were able to plug in. My condo is a high rise with lots of units each with their own parking space. There are no plugs inside the parking garage except a GIF plug in the car wash bay.

If I could plug in somewhere I would definitely have the EBH installed. Good on you, hope you can quiet down the neighbours.

 

I'll bet you won't get your neighbors to believe you despite any arguments or calculations to the contrary. Some people are like that.

ZC1

 

I DO have a "Killawatt" meter and the block heater is a 400W one. So if you left it plugged in 24 hours a day it would consume .4 X 24 kWhrs or 9.6 kWhrs per day. At your posted costs, that's $0.09476 X 9.6 = $0.91 per day. As you obviously drive some of the time, it's less than that. I'd offer the condo. association $150 per year for the privilege of 24 hour a day block heater use, just to maintain peace in the neighborhood.

BTW, the power factor to use is "1". It's a resistor, not a reactive load.

 

Does the EBH turn on and off to hold it at 140F? If it does being in a garage would reduce the cost.

 

The EBH is just a big dumb resistor. As long as its plugged in and has power it will create heat. Best thing to do is put it on a timer.

 

While others have corrected the wattage and power factor, I'll
correct the usage. You don't need to leave it plugged in 24x7, you just
need a 2-3 hour shot before leaving. There are diminishing
returns from leaving it plugged in any longer than that.
.
_H*

 

And I wonder if that would be better accomplished through a battery pack or even an UPS instead of though 120v AC.

Kremtok or others, can you be more specific about the MPG gains? I'd like to price out the savings at the pump vs the electricity cost. While Oahu gas prices are pushing $3.75/gal, we're also paying 20.5 cents/KWHr and our photovoltaic array isn't entirely covering our energy demands.

In general, after decades of experience across the nation, I've come to the conclusion that condo associations suck. You'll probably succeed in finding a way to power your EBH without their support before you can change their behavior to support you... or you'll find rocks in your tailpipe too...

 

Let your neighbors know that since they are paying to heat the garage, they will be paying a bit less as your 140 degree engine block will act as a heater as well. Actually, depending on how the garage is heated, the EBH may cost nothing additional to the building.

 

Kremtok...human race.
Human race...Kremtok.

Look on the bright side...with those neighbors, if it weren't the EBH, it would probably be something else.

Wonder what they'll do when you start charging your electric car in that garage?

 

I've seen Eliminator PowerBox units Canadian Tire advertised and been thinking if they could be used as portable power for EBH? After Nords posted the above comment I did some further research. I'm technically challenged and hope that you'll comment on the viability of this as a solution for these condo situation or perhaps when people are away from home (like work). I found the manual for this unit on-line - see attached. The unit "has 3 household outlets to power up to 600W of appliances and electronics simultaneously". More importantly (I gather) it states in the manual that the "maximum sustained load is 480W". Since the EBH requires 400W I believe this unit could power the EBH. I would connect it to a timer and use it at home and at work for 3 hours each per day. Recharge it at night inside my unit and/or at work (have to see how long does it take). What does everyone think about this alternative?
Kremtok,
If this works forget the condo board and "unreasonable" tenants just buy this unit and charge it once a day inside your unit then charge the EBH. For a little more than the $150/yr it was suggested to pay the condo you can buy this unit (on sale this week at $180). The other part I'm not sure of it is logistics - where to put this (inside the cabin or trunk?) and how to run the wire to the EBH? Any ideas? Living it outside the car maybe risky.
Thanks in advance for everyone's comments.
Gabe

 

My first reaction is that with only 28 Ah @ 12 V, this wouldn't work. But I'm technically challenged too.

When I moved into my new townhouse last fall with nowhere to plug in, I wondered aloud in CleanMPG whether a battery/inverter combo would be feasible. This was my thought process, pasted from that post:

"Some simple math suggests I would need an absolute minimum of 100 amp-hours, assuming a 12V battery: 400(W) ÷ 12(V) * 3(hours). That then gives a complete discharge, and with daily cycles I suspect even a deep cycle battery wouldn't last a year. With 100AH, I'm sure it would take a pretty big -- and heavy -- battery, not to mention the added weight of one with greater capacity. Even so, I'm guessing it would have to be charged daily. You folks correct me if my (mostly uneducated) assumptions are wrong, but it seems that the cost of battery(s) and inverter, conversion losses partially limiting the energy consumption advantage, and the hassle of lugging the battery back and forth would make this expensive and impractical."
​

While no one explicitly verified my analysis, no one disputed it either, so I let the idea die. Having said that, I reiterate that my assumptions are mostly uneducated and I stand to be corrected.

 

If I were you, I would no longer try to plug in your Prius. Most people can be an ignorant and violent lot, depending on circumstance.

It's not worth any possible retaliation - damage to your car and especially threats against your family - to save a couple of bucks

Put the extension cord away, and forget about it. Or you may need to rig up a security camera for your car and your suite.

 

I say fight on and keep us posted.