Archive for the ‘Projects’ Category

Copper Calculations

I’m planning on making some heat exchangers. It sounds fancy, but all I’m doing is coiling some soft copper pipe.

My goal is the most bang for my buck, so what’s the best way of arrangement of copper for dollars.

Here’s an example:

image of copper coil heat exchanger

My constraint: the water inlet and outlet are 3/4″ copper pipe.

For this analysis, I’m standardizing on a length of 50′ of coil.

The first obvious choice is using 3/4″ diameter to match the existing piping. A 50′ roll of soft copper pipe runs about $80 for 3/4″ diameter.

The main factor in heat transfer is surface area, so for a cylinder we need pi*d*h. The diameter is 3/4″ -> circumference of 2.356. For one foot, that’s 28.274 sq.in. of pipe. At $1.60 per foot, that’s 5.66 cents/sq.in.foot.

For cheaper, I could go with 1/2″ soft pipe. That would result in a faster flow though, which would give less time for heat to transfer, so I don’t know that it is a good choice. But we’ll look at it anyway.

The diameter is 1/2″ -> circumference of 1.571. For one foot, that’s 18.852 sq.in. of pipe. At $1.00 per foot, that’s 5.30 cents/sq.in.foot, a slightly better deal.

So the thinner pipe is slightly cheaper on a surface area basis. But the overall surface area is less and the water will flow faster so it won’t transfer heat as well, so that works counter to the point of a heat exchanger.

To get the same performance, we need the same cross section. Area of 3/4″ = 0.4418. Area of 1/2″ = 0.1963, or approximately half of the area of the 3/4″ diamter pipe. So if I double up the 1/2″ pipe, I can get the same flow as the 3/4″ pipe.

But what about surface area? That doubles! So slightly smaller cross section total, but (18.852 + 18.852)/28.274 = 33% more surface area. Looks like it is better heat transfer performance to have two 1/2″ pipes rather than one 3/4″ pipe.

Now let’s check the other part of the equation: cost.

The two 50′ pipes will cost double a single pipe (no, a 100′ pipe costs more than double, so I wouldn’t save anything by buying that and cutting it in half).

So 33% more performance for (100/80) = 25% more cost. Sounds like a good deal.

One more adjustment, just to make sure all the bases are covered: the area.

The 3/4″ pipe has (0.4418/(0.1963+0.1963)) = 12.5% more cross-sectional area. Which in theory would mean the water flows slower and has more time to absorb the heat.

So 33% more surface area but with a 12.5% reduction for flow rate, compared to 25% more cost for these two choices.

In conclusion, I’m going with the single 3/4″ pipe because it’s half the number of joints to solder therefore the double 1/2″ pipes are twice as likely to fail.

Iron is taken from the dust, And copper is smelted from rock.

Job 28:2

Connery-ish

There is now a Sean Connery accent option on Accenterator. Go try it out. It’s not as fun as the Australian accent generator because the vowels aren’t as dramatic, but it’s pretty good if you get the right collection of consonants in there.

If you need suggestions, here are some phrases to enter in the translator box:

  • Slow and steady wins the race.
  • This time is the last time.
  • Home sweet home is where I feel the safest.

In case you missed the link, go to Accenterator.com and click the Sean Connery button.

then they would say to him, “Say now, ‘Shibboleth.'” But he said, “Sibboleth,” for he could not pronounce it correctly. Then they seized him and slew him at the fords of the Jordan. Thus there fell at that time 42,000 of Ephraim.

Judges 12:6

German Accent

There is now a German accent option on Accenterator. Go try it out. It’s not as fun as the Australian accent generator because the vowels aren’t as dramatic, but it’s pretty good if you get the right collection of consonants in there.

If you need suggestions, here are some phrases to enter in the translator box:

  • Slow and steady wins the race.
  • What are you thinking about?
  • The only thing we have to fear is fear itself.

In case you missed the link, go to Accenterator.com and click the German button.

They called this out with a loud voice in the language of Judah to the people of Jerusalem who were on the wall, to frighten and terrify them, so that they might take the city.

2 Chronicles 32:18

Baby Names 2015

Subtitle: in which I improve the government’s records

Allow me to introduce to you the 2015 SFS List of Baby Names that Combine Similar Pronunciations. That baby name list is the place to go in case you are wondering what are the most popular baby names in 2015 regardless of how they are spelled. The Social Security baby name list does not adjust the rankings based on alternate spellings (like Catherine/Katherine), but SFS does.

It was just Mother’s Day, so the SSA released the name rankings for 2015. Last year’s new champion, Jackson is again the most popular boy’s name in the US. And it is widening the gap over Aiden – Jackson’s count is going up and Aiden’s count is going down. Not looking good for the former champ. No controversy for the girls – it’s Sophia again. Her numbers are going down, but all the top girls’ numbers are going down so that doesn’t mean much.

Some Stats

  • There was not a lot of change at the top for the boys. The top 10 names are the same, and in the same order except William and Jayden swapped spots at 7 and 8.
  • The top 8 names for the girls are the same as 2014, it’s just Mia and Emily swapped spots.
  • Noah is once again the highest-ranked boy’s name that has no spelling variations, at number 3.
  • Abigail is the highest-ranked girl’s name that has no spelling variations, at number 10.
  • Girl names still have more spelling variations than boy names (295/1000 vs. 203/1000 alternates)
  • Aiden still has the most spelling variations for the boys, but it dropped from 9 to 8. Aidyn is the one that dropped off the list.
  • For the girls, Adalynn leapfrogged the other names to claim the title of most variations – now at 7.
  • Sophia is still the runaway favorite for the girls, but the gap is closing. Sophia is on the decline

2015 Improved Baby Name List

Click on the link above and peruse to your heart’s content!

For all our days have declined in Your fury; We have finished our years like a sigh.

Psalm 90:9

Kvartal Lessons

My wife did not like our closet doors (they were large, heavy, and obtrusive), so we went to IKEA to procure an alternative method of hiding the contents of our closet.

Behold, the Kvartal:

photo of a Kvartal closet system from IKEA

I’m not going to go into details explaining IKEA’s closet curtain system and how it works, and I’m not going to give step-by-step instructions on how to install them. It was obvious enough from the instructions they provided.

What I am going to do is offer up my collection of Allen wrenches to the highest bidder.

For the Kvartal, you buy all the pieces individually. That lets you customize it to what you want. So we bought some rails, a few hanger thingies, and a few panels of fabric to go in the hangers. Oh, and the brackets for mounting the rails.

The downside with the modular approach is that, since they don’t know if you’re buying one piece or ten, they provide a little Allen wrench with each piece. It’s the same wrench, but I didn’t need 14 of them to install one closet system.

photo of a bunch of extra wrenches leftover from assembling IKEA furniture

For those who are keeping track: yes, there are only 13 in this photo. I lost one somewhere.

Sometimes, when I am assembling something, or fixing something, there will be a pile of spare parts left. In this case, I had a pile of spare tools.

Enlarge the place of your tent; Stretch out the curtains of your dwellings, spare not; Lengthen your cords And strengthen your pegs.

Isaiah 54:2

Baby Names 2014

Subtitle: in which I improve the government’s records

Allow me to introduce to you the 2014 SFS List of Baby Names that Combine Similar Pronunciations. That baby name list is the place to go in case you are wondering what are the most popular baby names in 2014 regardless of how they are spelled. The Social Security baby name list does not adjust the rankings based on alternate spellings (like Catherine/Katherine), but SFS does.

It was just Mother’s Day, so the SSA released the name rankings for 2014. Coming out of nowhere, Jackson is the most popular boy’s name in the US. The reigning champion for the last 8 years, Aiden, has been defeated. No controversy for the girls – it’s Sophia again.

Some Stats

  • There was a lot of change at the top for the boys. Not only did the top name change, but 2 names left the top 5 and were replaced with different names.
  • The top 9 names for the girls are the same as 2013, it’s just Emma and Olivia swapped spots
  • Noah is once again the highest-ranked boy’s name that has no spelling variations.
  • Girl names still have more spelling variations than boy names (291/1000 vs. 207/1000 alternates)
  • The boys still have the name with the highest number of alternate spellings (Aiden with 9 vs. Madelyn/Liliana/Layla/Kaitlyn with 6 each)
  • Sophia is still the runaway favorite for the girls, but the gap is closing. Sophia is on the decline

2014 Improved Baby Name List

Click on the link above and peruse to your heart’s content!

Now he called his name Noah, saying, “This one will give us rest from our work and from the toil of our hands arising from the ground which the Lord has cursed.”

Genesis 5:29

Tire Ladder

Inspired by Pinterest, my wife came up with some ideas for our yard. Here is the one I accomplished.

First step: acquire old tires.

This was an easy step. On my morning run I had seen four tires, abandoned on the side of the road. So I took the old minivan and picked them up. Then I went to the hardware store and got some lumber (some of that lumber is for a different project).

image of old tires in the back of a van

It’s nice having an old minivan into which I can throw muddy tires without worrying about messing anything up.
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