Does Switching to Geothermal Heating Make Sense?

So wondering if it would make sense to switch to geothermal heating & cooling…

Tl;dr = probably yes.

To answer this question, I grabbed and cleaned some data from Mass Energy and Environmental Affairs.  Here are the seasonal distributions of oil prices in the Boston area over the past 15 years:

oil-prices
Figure 1. Boston-area seasonal oil prices over the past 15 years. Prices are sampled weekly over the heating season, red lines are medians.

I modeled a few cases based off our oil usage in 1660 sqft and Boston-area oil prices over the past 15 years <insert piles of details & assumptions>.  MassSaves offers 0% 7 year loans and MassCEC offers a rebate.  Including these incentives, here is a snapshot of what the numbers would mean for us over a range of oil prices based on figure 1:

geothermal-vs-oil
Figure 2. Costs of switching to geothermal versus oil heating and AC.

I considered 3 cases given this model, (1) average oil price, (2) highest oil price, and (3) lowest oil price:

  1. If we switch to geothermal, against the 15-yr average oil price of $2.60/gallon we would pay $68 more per month in the first 7 years, and then break even on those extra payments 2.5 years thereafter. After the first 7 years we would only pay $58 monthly and after 9.5 years we would be saving at $194 per month compared to if we had stayed on oil.

  2. Against the maximum oil price of $4.18/gallon (which occurred between 2011-2014), we would save $65 per month in the first 7 years, and break even 1.4 years early. After 7 years we would be saving $327 per month compared to if we had stayed on oil.

  3. On the other end of the spectrum, if oil prices drop to $1.10 per gallon again (prices we haven’t seen since 2001), we would burn an extra $195 per month in the first 7 years and we could see granddoggies to the babies we don’t have yet before we break even in 27.3 years.

Since oil prices are trending upwards and unlikely to return to the lows we saw 15 years ago (considering political climate, falling prices of renewable energy, technology advances relating to energy, etc etc), it looks like switching to geothermal makes The Sense.  The only caveat is that this is so long as we can take on up to $200 per month cashflow out for the next 7 years.

References:

http://www.mass.gov/eea/energy-utilities-clean-tech/home-auto-fuel-price-info/heating-oil-price-surveys.html

http://www.masssave.com/en/residential/heating-and-cooling/offers/heat-loan-program

http://www.masscec.com/get-clean-energy/residential/ground-source-heat-pumps

Data Science is Science, Too

Two years ago today I was a Ph.D. Candidate.  I was thinking about defending and I was writing. I hoped to postdoc, or even seek nomination for a Fellows junior PI program.

Today, I hold a coursework masters degree, and I am a Data Scientist at a tech startup on Forbes 25 Next Billion Dollar Startups List.

It’s been a strange past two years.

I think someday I will be able to talk about it.  But the how of it essentially follows the story of this article: How A Dispute Led to a Grad Student’s Forced Mental Exam.

Only in my story I did not pursue any of my legal rights; I pivoted elsewhere, and elsewhere, until I landed here.  It hasn’t been easy and I still might not make it.  But today, here isn’t so bad.

Dyeing yarn! And knitting update

Long time no update on knitting projects.

I made some Westward hats, great pattern!  I plan to (and started) line hats with polar fleece so they will be soft and warm, but I hate sewing so it is very slow progress.

I have tried my hand at dyeing yarns in the past couple months and it is super fun!  It was my friend’s idea.  I’ve done it now 3 times.  It’s turned into a very scientific sort of thing with pipettes and graduated cylinders, stock solutions, and textbooks.  I don’t think I can buy dyed yarn ever again.

First time:

Second time:

Third time:

Knitting yarn holder

A major problem when knitting is that depending on how the yarn is pulled from the ball it can twist and create biased fabric.  This is bad for large garment projects because the clothes will be all twisty and not fit right.  However, many knitters don’t even realize that this is a problem.

Twist isn’t really only a yarn knitting problem.  It happens to DNA, ribbons, tape measures, garden hoses, tubing, toilet paper, everything that is basically a long string.  Imagine if you took a roll of toilet paper and pulled from the center instead of unrolling from the outside, you’d have a twisty mess that is not nearly as useful :D.

Techknitting blog has a great series about yarn twist.

To combat this problem, there are various yarn lazy susan contraptions I’ve seen around, most of which are crafted out of beautiful wood, cost lots of money, and hold only one ball of yarn or the balls are stuck in place. They also have design features that make them prone to tipping or in combination with unnecessary features to combat tipping that make the devices more unwieldy.

Toilet paper yarn holders in action
Toilet paper yarn holders in action

Following up on the toilet paper analogy, I’ve actually been using toilet paper holders for the past year. They are mounted to a pieces of wood bases and yarn balls are threaded onto the spring loaded holders. Looks ridiculous, not very compact, but works.

Since I’ve started color knitting, I think I’m ready for an upgrade. I don’t need the beautiful woodcraft look, but something that:

  • Holds multiple colored balls
  • Colors are hot-swapable
  • Reconfigurable for number of colors in project
  • Easy to transport / is not unwieldy
  • Somewhat durable
  • Works on uneven surfaces (low center of gravity, distributed load)
  • Cheap and easy to make
  • Isn’t bathroom joke fodder

Being the engineer/scientist/whatever it is that I am, I’ve been thinking about this and about how these requirements are met for other twist-prevention applications.  And I have designed something I’m pretty excited about.

Well, my love built it and it is great! Almost perfect!

Materials used were:
5″x8″ piece of MDF, 3/4″ thick
3/8″ pex pipe, cut to 12cm pieces
12″ 5/16″ threaded bolt, cut to 4″ pieces
5/16″ threaded insert nuts
1.5″ washers and rubber bands

Yarn axels were made by inserting yarn ball onto pipe with washer held in place by a rubberband. Posts were assembled by screwing threaded bolts into threaded inserts in MDF board. Yarn balls on axels fit over bolts and turn very smoothly!

Nut placement was great for 2 balls at 5″ apart. Nut placement for 3 balls was totally wrong, needed to calculate spacing better. Also need better care in drilling straight holes for nut inserts.

Yay!!!

Dandelion Trestle Love


It’s finally finished!!!!  And I LOVE it!!!

It was a rather ambitious project to make such heavy modifications but it all turned out just perfect!  The sleeves I planned were just right (if only I had followed my calculations properly the first time…) and the shoulder improvisation I did on-the-fly also turned out perfect!  I just can’t believe it all worked.

For all the gory details about the sleeves, see the first progress post; and for the much swifter shoulder process see the second progress post.

Of course, the Noro colors are beautiful and earthy — such a lovely contrast from my bolder first Trestle.  I would totally make this sweater again… maybe in cool colors?  The diagonal stitches are pretty cool I think they would make a great sweater all in one color, too.  Maybe for a men’s version, in stockinette. But how many of the same thing could I make and wear without appearing creepily obsessive?

Selfie of dandelion trestle
Selfie with bad light and messy room, but the sleeves and shoulders are so cute!

I saw another Asian person at the New Hampshire Sheep & Wool Festival!

So KC bet me that I would be the only Asian person at the New Hampshire Sheep & Wool Festival. I almost was, one other Asian woman spotted! But, I did have to go back Sunday to the Ball & Skein booth and the proprietress did remember me – maybe for being one of two Asian people?

I bought some yarn from the cutest family with adorable Alpacas! They were called Curly Q Farms, they’re not on Ravelry, but they let me pet the alpacas! The two daughters and their dad were so sweet. They suggested I buy a skein to make a hat or gloves, but I’m too lazy to wear accessories so I bought 5 skeins/1000 yds to make an In The Sky sweater. I have some Madelinetosh Pashmina in Antique Lace leftover maybe I’ll use that for a gentle contrast color.

I finally bought some yarn from Dirty Water DyeWorks. I’ve been eyeing it at Gather Here, but there were just so many colors at the booth. I bought some blue for a man sweater and some dirty off white color way aptly called Dirty Snow to make myself something. I’m actually excited because the one base is Blue Faced Leicester which I’ve never worked with before. And it’s superwash!

I found a new love in Ball & Skein yarns. The  colors were all just so beautiful and soft and lovely. I bought two reds, one skein each. Wish I had bought more but I can’t plan too many large projects at once or none would get done!

All in all, my first time going to a wool festival and I felt largely out of my demographic but well entertained. Can’t say the later was the same for him.

My Bosnian-Siberian Slipper Pattern!!!

I wrote my slipper mods into a pattern, download on Ravelry or free below!!!!! I have been working on my slippers and I think the mods have come together so nicely. I’m so excited!!

I am offering this pattern for free and outside of Ravelry (which is also free), but I ask in lieu of “payment” to please post projects on Ravelry with descriptions of your yarn, needles, sizing, etc so that other people can also benefit.  Thanks!

UPDATE: how did I totally miss that the white bands on the cuffs are totally different!? What was I thinking!!!
Continue reading “My Bosnian-Siberian Slipper Pattern!!!”

Dandelion Trestle Progress 2

Continued from Dandelion Trestle in-progress yay post

4/20/14

Sewed C’s first ever baby sweater. She was determined to make the Baby Yoda despite the seaming. Then spent a month trying to sew and later abandoning the pieces. I’m terrible at sewing myself, but I managed for the most adorable baby I know.

C's Baby Yoda
C’s first baby sweater ever knitted: Baby Yoda I just sewed it together

4/22/14

Yesterday was a knitting break. There were eggs to be dyed, and my wrist has been hurting; feels better now.

Very many stitches. Every round takes forever and a day. On the upside we’re decreasing 8 sts every other round… The first Noro ridge was really bright orange, right now it kinda looks like halloween gone wrong. Hope it works together in the end. Because each round takes forever like I said. And the sleeves took forever to do and redo (my own deficiencies caused this), so when this is done it is done and I’m not going back.

Checking out making galleries with WordPress!

Body:

Sleeves:

4/24/14

Last two evenings have had Costco trips. Managed only a handful of rounds since they’re so long.

5/2/14

Got back yesterday from trip. Thought I would work on my Trestle on the plane but it was difficult because the project has gotten kind of large and unwieldy.

Plus, I want to give my mom a pair of house slippers of the Bosnian-Siberian flavor for Mother’s Day, which is coming up. So I made the slippers on the plane. Mostly done with those.

My wrist has really started hurting! I think knitting tight stitches with a small gauge is the culprit. So I can only do so much at a time. Will have to get back to my Trestle after the slippers are done, but probably at a slower pace :(.

5/9/14

Been studying for quals ick. Today I finally went back to knitting my wrist had been getting better earlier in the week but then I helped to move a large piece of furniture to the third floor and it was hurting again :(. Been really wanting to make progress on my Trestle.

Last weekend I wrapped up the pastel Bosnian-Siberian slippers for my sister to take to my mom on Mother’s Day! But looking at the photos a couple days ago I realized a mistake from looking at the pictures :(. One slipper has 2 garter ridges of contrast color at the cuff and the other slipper has only 1 :(. Everything so sad.

Dandelion Trestle in-progress yay!

4/1/14

Starting with sleeves, modifying to make them in-the-round and recalculated!

4/2/14

Recalculated_sleeve_triangles.JPG
Sleeve triangles stuck together for in-the-round sleeves.

One night each – sleeve triangle sets ready to join. Mini sleeve swatch finished blocking maybe the 21cm wrist isn’t too wide, maybe a 19cm wrist will be too narrow hmm.

Sleeve triangle sets were worked like this (triangle increases are only at the joined edge of triangles – this is the underarm seam – the other edge is worked straight):

  • CO 3
  • (row 1) Left triangle in first st, purl underarm seam st, right triangle in third st
  • (row 2) Knit
  • (row 3) (left triangle) Knit to last st of left triangle, m1r, k1; purl underarm seam st; (right triangle) k1, m1l, knit to end
  • (row 4) Knit
  • Repeat last 2 rows until 29 sts per triangle
  • (increase row, rs) Knit to 3 sts before underarm seam st, m1l, k2, m1r, k1; p1; k1, m1l, k2, m1r, knit to end (= 31sts)
  • Knit
  • Repeat rows 3 & 4 once more = 32 sts per triangle + 1 underarm seam st, 65 sts total Continue reading “Dandelion Trestle in-progress yay!”

Sleeves for my new Trestle

Been planning about sleeves for my new dandelion trestle. The sleeves on my first trestle were way too wide for my taste, a problem that seems to crop up in other people’s project comments, too. I do like dolman sleeves, but narrow at the forearms and not billowy throughout; that’s something else another kind of sleeves I don’t like or know a name for. Since I already have a dolman-like sleeved version, I think I’ll try to make his next sweater with more normal / narrow sleeves; especially since it’s getting warmer out so excessive sleeves are unnecessary for warmth.

So I was thinking about the increase pattern of the lower sleeve triangles at a ratio of 1:3. We know that 1:1 increases, that is one increase on each end of right side rows, gives us 45-45-90 triangles. So anything increasing less frequently on one side would give us something less than 90 degrees.

I drew out the two starting triangles as they are written in the pattern approximating the angles based on the ratios of the sides and assuming right triangles for simplicity. It’s immediately obvious what’s wrong with the sleeves. The approx. 70 degree angle on the lower corner of the starting sleeve triangles tilts the forearms so they get way too wide too fast. The starting angle needs to be way way smaller.

Original sleeve schematics
Original sleeve schematics

Continue reading “Sleeves for my new Trestle”