I was speaking to a friend back home this morning and one of our usual discussion points came up - 'why do I like working for Microsoft so much'...it may not seem like I do sometimes (I'm a moaner) but I really do. I tried to explain all the usual stuff, cool things to play with, responsibility which you rarely get anywhere else, great place to work etc...but in the end what it really comes down to is the people who work here.Now I'm not going to get into a Mini-MSFT type discussion, its not perfect but it's pretty damn good being here. A prime example came up this morning on a discussion list, where we were discussing of all things high utility bills and whether baseboard electric heaters or oil filled radiators are more efficient. In most places this would never be resolved...not at Microsoft!. Incidentally I have the permission of the person who wrote this post to put his reply on here...usually we can never post internal discussions publicly. This reply is from Harsh:

"The difference is in a variable called the Power Factor. High school physics says electrical power is P= V*I.

However, in actuality, not all current is converted into power, and some is lost to impedance. Hence, actual power equation looks like

Where Φ is the angle by which the Voltage vector leads the current vector. Aka phase angle

The reason for the different equations being that the first equation holds for linear impedances such as pure resistors. Whereas all real world loads have resistance along with Inductance which adds the phase angle between current and voltage.

Ideally cos Φ should be 1 for perfect efficiency. However, in real world scenarios, power companies mandate that all appliances have cos Φ as close to 1 as possible. Standard appliances range from 0.8-0.95. This is done by adding capacitance to compensate for the loss due to inductance. Since impedance Z is measured as

Z = R+jX where

Higher the X higher is the angle, and hence lower is the power factor.

With base board heaters, the load is pure inductance + resistance, since these are the primary heat generating components. Inductance always lags by 90 (current lags voltage by 90), so higher inductance means the phase angle is closer to 90 than to 0. So base board heaters operate at power factors that are in the range 0.2-0.4

If you add that in the equation, this means, for the amount of power drawn, the conversion of current drawn to heat is very inefficient.

With portable heaters or space heaters, they add capacitance in parallel with the inductance circuit. Capacitance ensures that the phase angle is leading by 90 (current leads voltage by 90). And ends up compensating for the inductance. Also, by its nature, a capacitor is a energy storage device, and ends up reducing the overall power drawn, along with also increasing the efficiency with which the power/current drawn is converted to heat.

So even though the mechanism that creates heat is the same, base board heaters are more inefficient as compared to space heaters."