There have been posts in several threads about how much heat pumps have saved the users compared to the old systems.

How about if we dedicate a thread  to how much your heat pump has saved you?

This is a repeat of another post, but it seemed appropriate I add it here since you've asked for it.

I just had my Geo system installed in the fall.  I am trying to calculate how long it will take me to pay for it.  To figure this out, I had to estimate what my fuel oil use would have been had I kept that system.  I used my previous 4 years of fuel use and divided that by heating degree days and came up with an fuel use rate around 0.153 gallons per HDD (it ranged from 0.145 - 0.161).

I invested in sub meters so that I know exactly how many KWh's my geo system is using, so that is easy.  Subtracting what I actually spend on KWH's from what I would have spent on oil gives my savings.

Based on my oil use rate per heating degree day, I would have used over 230 gallons of oil since 10/22.  I used the cheapest price of oil on a weekly basis here in my area and assumed that I could purchase oil weekly at that cheapest rate (I understand that this is not possible).  With these VERY conservative assumptions, I still have saved almost $550 comparing what I have actually spent on electricity vs. what I estimated (conservatively) that I would have spent on oil.  (I've used almost 1,530 KWH on my geo system in the same amount of time.)

Now, this savings would have been much bigger with the price of fuel oil as it was when I purchased the geo system, but even with the fairly inexpensive price of fuel oil now (down to $2.75 this week), I am still ahead.

Attached is my spreadsheet in PDF format.  The values show usage on a daily basis which I realize is overkill.  The last column shows my daily savings over oil.  The last row of the spreadsheet gives my total savings for the time period.  At the very end is a pie chart showing me how much I have saved/paid towards my total geo installation price.

Ona, would you be willing to share the actual XLS?

Others here might also be in a similar comparison and could use your template...

My system consist of a Trane 3.5 ton, single stage scroll compressor, water to air, open loop with desuperheater. My home is about 2,300 sq ft, story and a half. It is very well insulated with 2x6 outside walls. I'm located in South East Michigan. Here is the bottom line. If the geothermal unit runs nonstop for a day, including the power for the well and heating my domestic hot water supply, it cost about $4 a day. The geothermal doesn’t run full time until the outside temp reaches about 11°F. So, if we really have a bad (very cold) month, the most I will pay for heating would be about $120 to $130. A bad month with my propane system was running about $450 a month keeping the house a 65 to 68°F. We now keep the temp set to 70° F 24 hours a day. With the propane system I also would shut off the upstairs, where now the whole house is being heated.

I would like to insulate the basement walls, as this is my last big heat loss area. I could also benefit from an air to air exchanger. When we run the cloths dryer of one of the bathroom fans, the system draws cold outside air to replace the warm air being removed. Having an air to air exchanger would recover some of this loss.

Eric, Wow that's a big savings you have there. I have 3 ton single stage compressor, closed loop with desuperheater. I used to have oil last year and spent almost $2000 and we were conservative by bringing down the theremostat to even 62. First time to have geothermal this year. I live in North Jersey with less than 2000 SF(including finished basement) and our bill this December is $275 for electric. We are keeping our between 66 and 67 degrees on 2 zones. Glad to hear you're doing great with your geothermal. My contractor adjusted the thermostat after I got my first bill so hopefully it'll get better this coming month of January although this week is 20 degrees with snow.

A few more point I should include, I have time of day use electric meter which brings the cost per kWh to 3¢. My system does not have a heat strip electric backup system. I have a propane fire place for backup. So far the only time I've needed it was ater about 3 days of -10 to -15 deg's F. Even then, the inside temp only got down the about 62 deg's F. I know a lot of folks will pull the breaker for the heat strips if their system has them. I know the heat strips really muck up the cost if they are being turned on more then needed.

danielz ~ I have no problem sharing my excel spreadsheet, but I must warn everyone before you open it that it makes sense to me, but possibly only me  :o)

I have to send the entire spreadsheet because a lot of the data in my cost tab comes from other tabs within the spreadsheet.  The point is, I could not easily pull out the cost worksheet from the entire document, so you get to see it all. 

For those of you not familiar with excel, just look at the bottom of the spreadsheet and the tab that has "$$$$" is the one that shows my cost info.  Feel free to look at the other tabs, but like I said before this may only make sense to me.  Feel free to ask if you have any questions.

Well ~ I just tried to attach and realized that my file is 125 KB - so too big to post.  I'll try to trim it down or if you would like me to directly email just let me know.

Ona, perhaps you could post it to a free upload site? Failing that an email copy would be appreciated.
craigb932001 at yahoo.com

Thanks and Merry Christmas!

Dick

Hi Ona,

 

If you do not mind, please email to [email protected] I can probably strip out the specific-user data and rebuild it as a template. (may be a day or so with the holiday)....and I'll repost...

 

Dan Z