Posted by Richard W. on August 19, 2009, 10:34 pm
>>
>>
>>
>>
>>
>> >>a vehicle AC/heating mechanism would be a Thermoelectric/ Peltier
>> >>Cooler.
>>
>> > Unless there have been some recent advances, Peltier heat pump
>> > systems
>> > have lower efficiency than a good mechanical system. Since any
>> > practical
>> > battery car will need an AC system, making it a 2-way heat pump to add
>> > heating capability s a logical choice compared to resistance heating.
>>
>> > Vaughn
>>
>> If there is no heat in the outside air then a heat pump doesn't work. You
>> will need some sort of heating devise. Gas or electric.
>>
>> My neighbor has a heat pump for his house, when it's 18 F out side his
>> heat
>> bill is about the same as mine and I have an electric furnace.
>>
>> Richard W.
> There's heat pumps and heat pumps. The one's trying to extract heat
> from air are going to fail in cold weather (ie 25degF or less) when
> you need them. The ones we have in the UK have a heat exchanger buried
> in the ground where the temperature is more constant. ( either
> trenches or a borehole)
> At around 30degFoutside, the coefficient of performance (COP) is
> around 4. ie you get 4x the electricity you put in out as heat.
We can get the underground ones here to, but at a much higher price.
Richard W.
Posted by Bob F on August 19, 2009, 8:23 pm
vaughn wrote:
>> a vehicle AC/heating mechanism would be a Thermoelectric/ Peltier
>> Cooler.
> Unless there have been some recent advances, Peltier heat pump
> systems have lower efficiency than a good mechanical system. Since
> any practical battery car will need an AC system,
I have no real need for AC. I use the AC in my car maybe 3 times a year. I could
survive fine without it.
Glad I don't live where you do.
Posted by clare on August 20, 2009, 3:40 am
On Wed, 19 Aug 2009 04:42:07 -0700 (PDT), Neo
>> The battery. In cold weather, they don't work well. In the climate
>> of places like North America in Winter, they may not work at all.
>> & BTW, how do you heat them or provide A/C?
>> It's gonna be a Summer car only!
>It is true that in extremely cold temperatures batteries do not
>operate af full efficiency.
>Also in extremely hot temperatures there is a risk that a battery may
>explode.
>Under hi load conditions a battery may generates heat and gases that
>need to be dissipated;
>both the Honda Insight and the Toyota Prius have static battery
>cooling vents for this.
>For cooling and heating the cabin the all electric Aptera uses a
>heatpump.
>Another possible albeit I have not heard of it being used for a
>vehicle
>AC/heating mechanism would be a Thermoelectric/ Peltier Cooler.
Too inefficient and complex to get the BTUs required.
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>>
>>
>>
>>
>> >>a vehicle AC/heating mechanism would be a Thermoelectric/ Peltier
>> >>Cooler.
>>
>> > Unless there have been some recent advances, Peltier heat pump
>> > systems
>> > have lower efficiency than a good mechanical system. Since any
>> > practical
>> > battery car will need an AC system, making it a 2-way heat pump to add
>> > heating capability s a logical choice compared to resistance heating.
>>
>> > Vaughn
>>
>> If there is no heat in the outside air then a heat pump doesn't work. You
>> will need some sort of heating devise. Gas or electric.
>>
>> My neighbor has a heat pump for his house, when it's 18 F out side his
>> heat
>> bill is about the same as mine and I have an electric furnace.
>>
>> Richard W.
> There's heat pumps and heat pumps. The one's trying to extract heat
> from air are going to fail in cold weather (ie 25degF or less) when
> you need them. The ones we have in the UK have a heat exchanger buried
> in the ground where the temperature is more constant. ( either
> trenches or a borehole)
> At around 30degFoutside, the coefficient of performance (COP) is
> around 4. ie you get 4x the electricity you put in out as heat.