Engineering Operations, Program Management, and Leveraging the Bitcoin Blockchain API's of BlockCypher.Com

Leveraging the Bitcoin Blockchain to streamline Engineering Operations (w/ BlockCypher's Secure Transaction API's) - Example:

Professional Engineering (PE) - Mechanical Exam Preparation & Video Tutorials

Free Mechanical Engineering PE Exam Prep

For all those preparing to take their Professional Engineering (PE) exam, this section is dedicated to you: Discussions of not only problems but strategy will fill this blog post. I will dedicate as much time to this as I have available.

STEM students are also encouraged to review the videos and post questions. (I will not answer simple questions or provide more detailed guidance for professionals, though. However...

There will be a section of much more advanced problems and solutions to those willing invest a little bit of Bitcoin (OK, I'll accept FIAT currency too) - STAY TUNED and GOOD LUCK on your exam!

Please note: My intention is to help here so questions/solutions I post here are well researched -  if you find ANY error, please don't hesitate to let me know right away.

Free Video Tutorials

Mechanical PE Exam Preparation - Introduction:

Bernoulli - Simple Tank Pressure Problem & Solution:

Advanced Video Tutorials Paid Subscription

Disclaimer: All prices are subject to change at ANY time. It should be known that Bitcoin is a highly volatile currency and, as such, its exchange rate will change accordingly. These online video tutorials have no warrantee and are provided on an as-is basis. Further, your access to these videos are NOT to be interpreted as a guarantee that you will pass the PE exam in ANY WAY. By purchasing access to these video tutorials, you acknowledge and accept any and all liability including that described herein.

Bernoulli - Advanced Tank Pressure and Pipe Flow Problem & Solution:

This Approx. 11 min. Tank Pressure and Pipe Flow Problem tutorial explores typical solution strategy, formulae, and common pitfalls of the Mechanical Engineering PE exam: A La Carte Price is 0.0139 Bitcoin (~ $8.00)

Access Link for this tutorial

https://www.youtube.com/watch?v=62QZ_ZscMKU

Mechanics of Materials - Advanced Sleeve and Rod Problem & Solution:

This Approx. 6 min. Steel Sleeve w/ Brass Rod Thermal Expansion Stress Problem tutorial explores solution strategy and formula used in the Mechanical Engineering PE exam: A La Carte Price is 0.0139 Bitcoin (~ $8.00)

Access Link for this tutorial

http://youtu.be/DXpA9YQlClQ

Mechanics of Materials - Advanced Eccentric Loading Fastener Shear Stress Strategy:

This Approx. 6 min Eccentric Load Fastener Shear Stress Problem tutorial explores the unusually simple solution strategy used in the Mechanical Engineering PE exam: A La Carte Price is 0.0139 Bitcoin (~ $8.00)

Access Link for this tutorial

http://youtu.be/y0sWso484JM

Dynamics - Frictionless Loop Conservation of Energy Problem & Solution:

This Approx. 10 min Dynamics tutorial reviews the concept of Energy Conservation in a Frictionless loop system with a spring, solution strategy, and common pitfalls used in the Mechanical Engineering PE Exam: A La Carte Price is 0.0139 Bitcoin (~$8,00)

Access Link for this tutorial
http://youtu.be/xRxpP3Gmsoc





More Tutorials Coming Soon!

About Pricing:

One-Time ALL Inclusive Plan: 0.10629 Bitcoin per user (roughly $60.00 @ the 2/21/2014 exchange rate). This plan allows access to ALL videos created in this Advanced Video section (including updates). This section will have 1) Sample Problems & Solutions, 2) Advanced Strategy for the Mechanical PE Exam Strategy, and 3) Ancillary advice.

A la carte: This plan allows access to each paid video created in this Advanced Video section (including its updates). See the particular video for pricing. The price WILL VARY depending on the length and complexity of the Problem & Solution.

Payment Process:

Bitcoin (BTC)

For those that like to transact in Bitcoin, simply send me an email @ JJBJManagement@Gmail.Com with your intent to purchase with an email address that I can register with YouTube (for Video access). Once I receive your email and payment, I will respond letting you know that you have access.

Of course, if there are any questions, please do contact me.

Bitcoin Payment Address:

14Gd8ewhyi1rfaKfXoMUYbRTWZgAbDmGeQ

FIAT Currency ($ USD)

TBD

Why is Electrical Switchgear Important to Critical Facilities? - A Non-Technical Explanation

Why is Electrical Switchgear Important to Critical Facilities?

(A Non-Technical Explanation)

Nick Cage on top of one of the largest critical telco buildings in the world in the movie "City of Angels"

Street-Level View of 420 S. Grand (part of The Madison Complex)

The Basics:

Electricity ALWAYS seeks the path of least resistance on its way to Ground. By ground, we literally mean the earth that we walk on. It's just one of many physical facts. For example, a lightning bolt will always bypass insulation to try to find conductive metals (or non-pure water or a golfer...) on its way to where it is going.

A Short-Circuit

An electrical short aka "Short Circuit" is a technical term that describes a condition in which the electrical current is provided a short-cut to ground. For example, if we were to place a piece of metal wire between the terminals of a small (e.g. 9 Volt) battery; that condition would be considered a "short". This is simply because the current induced by this battery is meant to flow through the circuit of the device we are trying to provide power to - NOT to go directly from one terminal to the other (the short).

Switchgear

In general, there are two basic conditions that need to be mitigated: 1) Too Much electrical current (or power) and 2) Too Little electrical current (or power). Have you ever witnessed the lightbulbs in your bathroom flicker when using a hair dryer? This is because your hair dryer is drawing a greater amount of current from your electrical circuits that other devices. Switchgear; or more precisely; the circuit-breakers (the GFCI outlet in your bathroom is a tiny circuit-breaker)  mounted inside a switchgear panel, regulate the amount of current drawn into what is called a "branch-circuit". (see the Single-Line drawing below)

Example Single-Line Diagram (ATS Interlock in Green & Generator in Orange)

In the above Single-Line diagram, the backward-looking "C"s are symbols for each circuit-breaker.

Critical Facility Power Outages, the ATS, and the Generator

In the event of a loss of Commercial Power (COMM'L SERV depicted top-center of diagram),  the integrated and interlocked ATS or Automatic Transfer Switch (interlock highlighted in Green) senses a loss of power, "disconnects" from the commercial power, and "connects to" the Stand-by Generator (highlighted in Orange). While the Generator ramps up to speed, the data center batteries discharge power to the critical circuits (those mandated per code & company regulation: Fire/Life/Safety, etc). Once the Generator is ready, the critical circuits are transferred until Commercial Power is back on-line.

Why should Nicolas Cage Care? 

Well, if he were dumb enough to stand on top of the antennas again during an LA thunder storm, he might care that these critical facilities are carefully engineered by one entire company group responsible for ensuring that ALL electrical currents go where they need to go (and nowhere else). [But, I still wouldn't recommend anyone stand near those antennas - for many other reasons]

Bitcoin - Is this the "New Gold Rush"? How can I make $$$ on this kind of investment?

Bitcoin

Data points used to estimate Bitcoin trend depicted by various traditional forecasting models starting Week Ending (WE) 5/05/2013. NOTE: Vertical Axis Removed on Purpose, see below for explanation.

  

The Legal Mumbo-Jumbo:

Disclaimer: The following information is NOT intended for the purpose of providing investment advice. It is solely up to the reader to educate her/himself on Bitcoin or any other form of trade. The information and/or any product and/or service provided as described herein is meant for educational purposes. In other words...Buyer Beware...Enter At Your Own Risk...Mark Well Me Words, Mateys!...


Vertical Axis of Graph Depicted Above: You should realize; after reading the above Disclaimer; that I purposefully removed the Y-Axis so that NOONE could construe my graph as providing ANY investment advice. However...

I am providing a tool to IMPROVE CHANCES of $UCCE$$.

The Data Target Forecasting Tool

(a 10 minute YouTube Video Tutorial - for those that don't like reading LONG Blogs)

Payment Methods (PayPal Button for Instant Download) Bitcoin Button for file delivery via email:

Pay With Bitcoin

 

(Unsure of Purchase? See Below)

The Data Target Forecasting Tool Accuracy

(a 7 minute YouTube Video Tutorial - How to Measure Tool Accuracy)

After Testing with Bitcoin data...

Remember this metric --> 7.0% <---  (taken 1/15/2014)

Remember this metric --> 4.1% <---  (taken 1/16/2014)
Remember this metric --> 2.6% (or 97.4% accuracy) <---  (taken 1/20/2014)

the Excel model achieved the above results.

So, How much $ can be made?

     Well...there have been reports of sole proprietors refusing to accept Bitcoin as payment (If I recall correctly, it was a Pizza vendor). At the time, Bitcoin was worth ~ $5.00. Had the Pizza vendor accepted the Bitcoin, as in this example, he would have made ~ $3,800.00 on the sale of one pizza [at the current price of about $950.00 per Bitcoin].

      So?...That could be just a fluke.

     I encourage you to look up Bobby C. Lee's YouTube video talk at Stanford University. He answers some of the most hard-hitting questions with regard to this "currency". Note: Bobby C. Lee is the CEO and a co-founder of BTC China, China's Bitcoin exchange - an exchange that was HEAVILY impacted by the Chinese Government's decision to disallow future exchanges through his company.

     Did this stop Bitcoin values from rising?... NO. 

Wait a second. How does the Excel model work? And will it always be this accurate?

     It works by using algorithms that are typically taught in Business & Engineering graduate schools ( in those classes that make even the sharpest minds go, huh? - not counting some of my quick-witted brethren who already know all this stuff ).

      And, NO. It may NOT ALWAYS be this accurate. It could be MORE or LESS accurate. It's always dependent on the input data - just WHY do you think certain agencies have invested so much into data-crunching machines? Not for their health, I'll tell ya!

 Okie Dokie. So how much for this Excel Modeling Software? About the same cost as a bagel & latte...$9.00
(see PayPal button below)

 Since you've read the disclaimer, you already know that my primary objective here is to spread knowledge. So below is a little of the Who, What, Why, and How of Bitcoin -->

Who?

     Satoshi Nakamoto!, that's who. Or an individual or group of people calling themselves Satoshi Nakamoto.

What?

     Have you read the White Paper by Sitoshi Nakamoto? If not, I encourage you to read, re-read, and read again. In summary, it is a cryptology-based mathematical accounting system used to ensure:

     1) Value by limiting the number of Bitcoin that will ever be available.

     2) Transparency by providing a publicly available accounting of every Bitcoin transaction ever made - to the extent that this accounting is necessary to remove transaction fraud.

     3) Ease of Use by allowing free (or nearly-free) transmission of the Bitcoin "currency" [if you can actually call it that - which remains to be seen in a government/regulatory legal sense] for any product or service offered in the world [that accepts Bitcoin as payment (or at least a BTC/local-currency exchange)]

Why?

     Well, I'm not sure but I could definitely guess.

     Included in my guesses is the theory that "Satoshi" published his (her/their) white-paper as a means to say "Look What I can Do?" - the story goes that he (she/they) simply posted the paper to a "computer-geek" web site (for developers by developers) in order to challenge them to do something with it....which, obviously, they did.

     And, now YouTube is FULL of Techno-Explorers claiming to have found The Promised Land.

How?

     Go to Bitcoin.org for a pretty in-depth tutorial on all of the ways to purchase/exchange Bitcoin for FIAT currency and/or products & services. Also listed are the many resources from which you can educate yourself on this new phenomena.

(Thank you all for your recent emails. I will be updating to PayPal (or similar) payment system soon )

     By the way - I recently received an email asking the logical question: Where do I get my data from?? (You read the disclaimer, right?). I really can't TELL you where to mine your data, HOWEVER, I can provide some pretty good sources of information. See the following:

Erik Johansson's Financial Data Blog (for Bitcoin)

     Not only does Erik's blog provide great information, he helps PROVE MY POINT. :)

Sample Screen Shots (in addition to top Graphic):

The 3-Period Moving Average Forecast vs. Actual Data:

The Linear Trend Forecast vs. Actual Data:

More Information Regarding Tool Accuracy:

Why does the Bitcoin forecasting tool work so well?

1) The tool MINIMIZES FORECASTING ERROR : The Power of Mean Absolute Deviation 

Buy Now While Supplies Last! (I always wanted to say that):

Payment Methods (PayPal Button for Instant Download) Bitcoin Button for file delivery via email:

Pay With Bitcoin

For STEM Students

STEM

(Science, Technology, Engineering, and Mathematics)

Note to Parents:

     I've created this area for your students inside of this Engineering blog with the specific intent for him or her to be provided an opportunity to compare & contrast what they are learning in school to those ideas that are used in an actual Professional Engineering context - the other areas of this Blog. This area is also meant to discuss areas that I've noticed to be somewhat difficult for the typical math & science student.

Third Degree Polynomials:

How do you factor X^3 - 27 or X^3 - 8 or X^3 - 125 or X^3 + 64 or X^3 +/- C^3?

     Many students now being introduced to Polynomial factoring have difficulty with this and many other mathematical concepts. The following tutorials make understanding these concepts much easier:

Private Online Tutorials (Produced For Family, Friends, Associates, etc.):

Cubic Equations - How Cubic Equations are Factored - A Geometric Proof

Readily Available Online Tutorials:

Cubic Equations - How To Find Roots - A High Level Overview

Cubic Equations - How To Factor Cubic Equations - An Introduction

The Hospital Operating Room vs. The Data Center: An HVAC Synopsis (ASHRAE)

     The Executive Summary

          The purpose of this blog post is to compare and contrast two types of critical facilities as they pertain to the HVAC heat transfer design strategy. The Hospital Operating Room (OR) and the Data Center Equipment Floor Space. This post is supplemented with consolidated data and information from ASHRAE (Journal and Standards) as well as my own experiential data.

 Who is the Client?

Aka, "the V.I.P.", aka "the focus", aka "the revenue stream", aka "the reason you exist".

Depending on who you ask, the revenue from a data center could range from many thousands to tens of thousands of dollars per square foot per year. Not having proper heat transfer to cool the equipment can be a risky proposition. In a hospital Operating Room (OR) where we consider the possible loss of life, I'm fairly confident that the risk is far greater.

     What are the Requirements?

As a seasoned Project Engineer will tell you, often times the client doesn't know what he or she wants. However, it is the Engineer's job to provide options, to communicate those options, and to provide possible solutions in a manner that the client can understand.

While there is an almost infinite number of variables involved; the ME is skilled at narrowing down the requirements to basic principles (e.g. Temperature, Pressure, and Flow). More specifically, here we discuss Heat Transfer, Humidity Ratio, Laminar air flow, and Air Quality.

 Heat Transfer

In general, the amount of space heat (BTU/Hr) to be removed originates from people, equipment, or the heat absorption from external sources. Although the hospital Operating Room will have heat generated from the surgeon and his or her staff, the equipment, and the lighting; by far the most extensive amount of air conditioning energy will be from the conditioning of 100% outside air required to exhaust all odors & contamination. The heat needs to be removed (or added) such that the OR is always kept at the optimum Temperature and Humidity levels as mandated by the client and codes.

As mentioned below in the airflow discussion, the Heat Transfer or Cooling Load profile in a data center (DC) is very different from a hospital OR but the underlying principles remain the same. On average, the DC equipment waste heat is on the order of 200 Watts per Square Foot with very little cooling load from technical staff (or even lighting). Taking into account experiential data on stand-by engine size and design power usage, this represents an estimate of 10,000 Sq Ft. of equipment space (or rack foot print). Of course, the required heat transfer in a typical hospital OR is minuscule compared to a data center.

 Relative Humidity (RH)

Driven by Temperature, the target RH level in a Data Center may be difficult to maintain tightly but can vary from 45% to 55%

according to the expanded ASHRAE range for Data Centers. While the hospital Operating Room (OR) requires a lower RH from 20% to 35%. OR's have typically mandated the 35% minimum but newer (ASHRAE 170) standards recognizing the removal of flammable materials within the OR require a 20% minimum which may save money depending on psychometric design.

         Laminar vs. Turbulent Air Flow in the OR

It may be obvious that the goal here is to minimize contaminated airflow over the body of an OR patient. The non-trivial issue is how. For example, how does the Mechanical Engineer design the HVAC system airflow to ensure that particulate matter is kept away from the patient? If the airflow enters the room from the ceiling and falls to the floor, there is a chance that contaminated particles from the floor are kicked up and re-circulated to the patient. To minimize contamination, the engineer must ensure that the air flow passes over the patient once and is NOT re-circulated toward the operation area but returned to the system for filtration and/or exhaustion.

The Multiple Panel System:

At much lower airflow rates than the typical system, these perforated "laminar airflow panels" are designed with the assumption of straight air movement toward the floor from the face of the outlet. The laminar airflow concept developed for industrial clean room use has attracted interest from some medical authorities. There are advocates of both vertical and horizontal laminar airflow systems, with and without fixed or movable walls around the surgical team. Some medical authorities do not advocate laminar airflow for surgeries.

The Air Curtain:

Air curtains are jets of air projected across envelope openings with the intention of reducing air exchange and the entrance of dust and insects, for example. The performance of air curtains is highly dependent on factors such as jet characteristics, wind, and building pressurization. In the OR, they are generally created using a couple of linear slot diffusers with supply plenums - designed to deliver air evenly over the length of the air slot.

Now, due to the effects of buoyancy, air entering a room at a relatively cold temperature to its surroundings start off at a low velocity but will increase its speed toward the floor. This happens much the same way as an iron ball falls to the bottom of a deep pool of water. And, if this happens, there is a much higher chance of the flow becoming more turbulent and kicking up contaminated particulate matter back to the patient.

Immunosuppressed patients (including bone marrow or organ transplant, leukemia, burn, and AIDS patients) are highly susceptible to diseases. Some physicians prefer an isolated laminar flow unit to protect the patient; others are of the opinion that the conditions of the laminar cell have a psychologically harmful effect on the patient and prefer flushing out the room and reducing spores in the air. An air distribution of 15 air changes per hour supplied through a nonaspirating diffuser (unidirectional downward airflow from the ceiling with minimum entrainment of room air) is often recommended. With this arrangement, the sterile air is drawn across the patient and returned near the floor, at or near the door to the room.

 Airflow in the Data Center

In contrast to the OR patient who is always located in the same place, the "hot spots" on the floor of a Data Center may not only be in different areas but the floor configurations of the equipment may change. Where it is critical to keep a patient clean of any contaminated particulate matter in the OR, it is critical to efficiently cool Data Center equipment by properly aligning cooling capacity to the heat sources.

Floor Space Configuration:

While the precursors to the modern data center had equipment mounted on the concrete slab with flexible duct drops hanging from the iron supports above; more modern data centers (outside of the newest modular construction) are typically designed with Hot/Cold aisle separation between inlet/outlet of the equipment cooling fan flow. As many know, the reason for this separation is to minimize the mixing of cold & hot air streams leading to inefficient cooling. As eluded to above, many variables may reduce the efficiency of heat rejection on the floor including variable equipment manufacturer / type / heat output; inconsistent and/or non-homogeneous equipment floor space planning; and surrounding structure impeding the proper flow of air.

Heat Transfer Strategy:

Of course this is an over-simplification but removing heat from data center equipment is sort of like blowing out a candle. If you blow the wrong way or not hard enough, the candle will stay lit. In essence, blowing the candle the "right way" in a data center is aligning the equipment along the floor space such that the air flow will transfer the heat efficiently; making sure that the source of the cooling is as close to the equipment heat sink as possible such as in an in-line cooling configuration; and/or ensuring that the cooling capacity is large enough to take the heat away more efficiently as is the case for liquid cooling inside the server racks. It should be noted that this type of cooling is generally not accepted due to lack of maintenance access and leak risks but is growing in popularity.

 Computational Fluid Dynamics (CFD)

CFD models of particle trajectories, transport mechanisms, and contamination propagation are commercially available. Flow patterns and air streamlines are analyzed by computational fluid dynamics for laminar and turbulent flow where incompressibility and uniform thermophysical properties are assumed. Design parameters may be modified to determine the effect of airflow on particle transport and flow streamlines, thus avoiding the cost of mockups.

Some major features and benefits associated with most computer flow models are:

• Two- or three-dimensional modeling of cleanroom configurations, including people and equipment
• Modeling of unidirectional airflows
• Multiple air inlets and outlets of varying sizes and velocities
• Allowances for varying boundary conditions associated with walls, floors, and ceilings
• Graphical representation of flow streamlines and velocity vectors to assist in flow analysis
• Graphical representation of simulated particle trajectories and propagation

          Research has shown good correlation between flow modeling by computer and that done in simple mockups. However, computer flow modeling software should not be considered a panacea for design because of the variability of individual project conditions. "It is…more difficult to model the air currents resulting from complex mix of convective, radiative, and conductive heat flows in a typical office with high induction outlets…we found very little data that draws a parallel between CFD and physical measurements in these situations" - see You Have to Prove It by Dan Int-Hout, Fellow ASHRAE (ASHRAE Journal October, 2013)

 Air Quality

Hospital operating rooms may be classified as cleanrooms, but their primary function is to limit particular types of contamination rather than the quantity of particles present. Cleanrooms are used in patient isolation and surgery where risks of infection exist.

Systems must also provide air virtually free of dust, dirt, odor, and chemical and radioactive pollutants. In some cases, untreated outdoor air is hazardous to patients suffering from cardiopulmonary, respiratory, or pulmonary conditions. In such instances, treatment of outdoor air as discussed in ASHRAE Standard 62.1 should be considered.

Outdoor Air Intakes. These intakes should be located as far as practical (on directionally different exposures whenever possible), but not less than 25 ft, from combustion equipment stack exhaust outlets, ventilation exhaust outlets from the hospital or adjoining buildings, medical-surgical vacuum systems, cooling towers, plumbing vent stacks, smoke control exhaust outlets, and areas that may collect vehicular exhaust and other noxious fumes. The bottom of outdoor air intakes serving central systems should be located as high as practical (minimum of 12 ft recommended) but not less than 6 ft above ground level or, if installed above the roof, 3 ft above the roof level.

Exhaust Air Outlets. These exhausts should be located a minimum of 10 ft above ground level and away from doors, occupied areas, and operable windows. Preferred location for exhaust outlets is at roof level projecting upward or horizontally away from outside intakes. Care must be taken in locating highly contaminated exhausts (e.g., from engines, fume hoods, biological safety cabinets, kitchen hoods, and paint booths). Prevailing winds, adjacent buildings, and discharge velocities must be taken into account. In critical or complicated applications, wind tunnel studies or computer modeling may be appropriate.

Air Filters. A number of methods are available for determining the efficiency of filters in removing particulates from an airstream. All central ventilation or air-conditioning systems should be equipped with filters having efficiencies recommended by code and/or ASHRAE standard. Appropriate precautions should be observed to prevent wetting the filter media by free moisture from humidifiers. Application of filter beds should follow ASHRAE Standard 170. All filter efficiencies are based on ASHRAE Standard 52.2. For example, a hospital OR filter of MERV 16 rating is designed to remove particulate matter in the size range of 0.3 to 1.0 micrometers. In the surgical environment, this will take care of bacteria, smoke, some viruses, and droplet nuclei.

Optical particle counters (OPCs) are widely used and likely to become more so. They are very convenient and provide real-time, size-selective data. Individual aerosol particles are illuminated with a bright light as they singly pass through the OPC viewing volume. Each particle scatters light, which is collected to produce a voltage pulse in the detector. The pulse size is proportional to the particle size, and the electronics of the OPC assign counts to size ranges based on the pulse size. ASHRAE Standard 52.2 defines a laboratory method for assessing the performance of media filters using an OPC to measure particle counts up- and downstream of the filter in 12 size ranges between 0.3 and 10 μm. Filters are then given a minimum efficiency reporting value (MERV) based on the count data.

 Other Factors

The "Black Box" or "Closed System" are analogies that Engineers like to use to define the borders through which the various inputs & outputs of the system cross. Although this discussion has been limited to either the Hospital OR or the Data Center floor space, ANY ingress or egress of air flow must be reviewed and integrated as a complete system to minimize contamination. For example, air ingress from other parts of the hospital from either rooms or from elevators must be taken into account with the use of special sterile procedures.

How Can You Save 27% on Your Heating Bill This Year??

Winter's Coming! - How Can I $ave on Heating Co$t??

     Ok, let's get practical for a sec. Mech E's that have chosen to specialize in HVAC/R are just full of equations. So, let's pull out our handy-dandy equation for Furnace Fuel Consumption. It says:

Furnace Fuel Consumption = (24 * Q * DD) / (deltaT * HV * Eff)

where,

Q** is the amount of heat being lost to the bitter cold outside in BTU per Hour ~ 85,708 BTU per Hour,

DD^^ is the number of Degree Days in the Heating Season ~ 6,696 Days,

deltaT is the difference between the outside and inside temperatures in degrees F ~ 37.2 degrees F,

HV++ is the Heating Value of the Fuel (for Natural Gas HV ~ 1,100 BTU per cubic foot)

and Eff is the efficiency of YOUR furnace (this is something you'll probably find on that yellow sticker to the side of your unit)

(I'm using the "Annual Fuel Utilization Efficiency" or AFUE) ~ 80%

Note: These estimates are for Northern Virginia but you can gather your own information @

^^www.wrcc.dri.edu

**www.calculator.net/btu-calculator.html

www.noaa.gov (available when the government re opens)

++I simply Googled the Heating Value (HV)

     Pretty simple, right? Well, not really. The heat being lost is dependent on deltaT, the time of day, the physical orientation of your home and the insulation of your house. However, you can greatly simplify your life by making a few assumptions & estimations - as you'll see, this is perfectly fine (and expected if you're an ME).

     So, the result is…(drum-roll, please)……….420,748.4 cubic feet of natural gas per annual heating season.

     So, how much can you save by turning down the thermostat to 65 degrees F during the winter?

  Q ~ 62,208 BTU per Hour,

DD ~ 4,896 Days,

deltaT ~ 27.2 degrees F,

HV ~ 1,100 BTU per cubic foot),

and Eff is ~ 80%   

     So, the result is…(drum-roll, please)……….305,384.7 cubic feet of natural gas per annual heating season. (a 27% savings on your bill)

     OK, freezing your family this winter might not be what you had in mind...BUT....if you look carefully at the equation above, there are a host of things that can be done to save on you heating bill this winter. You can calculate your potential savings by comparing the cost of a more efficient system (one with an AFUE of say 90%). You can also replace your windows with ones that have a better "U-factor"...I'll explain that when I have more time to blog again.

     Until then, Cheers!