Hacker Perspective: Fat Storage and Retrieval

Caveat: this information on this web page is based upon material gathered from a number of sources including the internet. Therefore, use this material cautiously at your own risk and only with the advice of a physician

Introduction

Claude Shannon was once asked "do you believe machines will ever be able to think?" to which he replied: I'm a machine and you're a machine, and we both think, don't we?" This got me wondering if some biological processes might be better explained by comparing them to technological processes.

Heating and Cooling

We start with a mechanical (non-smart) thermostat with a mode switch set to AUTO so HVAC (heating ventilation and air conditioning) system will automatically shift between heating and cooling. The thermostat is set for 22 °C (71.6 °F) with a one degree gap meaning that we will heat up to 21.5 °C and cool down to 22.5 °C

Furnaces + Air Conditioners

  1. The thermostat drops below 21.5 °C which starts the furnace
  2. Let's assume for a moment that we are heating by burning natural gas. According to this article we can expect a temperature of 1950 °C (3542 °F) which is much too hot (and dangerous) to send directly into a building. So engineers employ a heat exchanger which acts as a buffer (we want heat but not high temperature)
    Reference: diagram
  3. As the temperature of the air-side of the heat changer rises, a thermostat in the furnace energizes a large fan (blower) to direct air onto the heat changer before it is directed into the heating vents of the building.
  4. As room temperature rises, the thermostat reaches set-point telling the furnace to stop burning gas
  5.  The blower will not stop sending heat into the building until the heat exchanger cools down to a reasonable temperature. This means that a small amount of temperature overshoot is possible when in heating mode.

Heat Anticipator vs. Smart Thermostats

  1. With mechanical thermostats, a small adjustable device known as an anticipator will add a tiny amount of heat to the thermostat so that the call for heat will be terminated sooner. This is done to reduce/eliminate overshoot
  2. Smart thermostats are little computers that can track how far the temperature will fall after a heating call begins. They will then watch how fast temperature rises then will attempt to predict the correct time to end a heating call to minimize overshoot. Depending upon how well they do this job, they may shorten or length the time of the next heating call.

Flopping

  1. A poorly designed system with lots of overshoot might drive a heating system into cooling mode (provided the thermostat is equipped with an auto mode)
  2. If you are using a dump thermostat then you are out of luck
  3. If you are using a smart thermostat then it may decide to not switch modes for five, or more, minutes

Heat Pumps

  1. Since heat pumps heat (and cool) using refrigerant, they do not build up high internal temperatures so do not need to run after the thermostat is satisfied.  

 


Back to Home
Neil Rieck
Kitchener - Waterloo - Cambridge, Ontario, Canada.