Switching to Steffes ETS unit
![](https://secure.gravatar.com/avatar/120ede69fffefccb27b8697366e5e841?s=52&d=https%3A%2F%2Fimages.greenbuildingadvisor.com%2Fapp%2Favatars%2F200x200%2Fm.png&r=g)
I think I asked this question on here some time ago, but can’t remember the general take on it… In the next few weeks I have to A) Replace my 10 year old oil tank at a cost of $1700 OR B) Get rid of my forced hot air system altogether and install a Steffes ETS unit at a cost of $3140 (plus I can get time of day rates/use).
My question is what do I do!! I am just looking at oil receipts now and in the last year they have went from $0.70/litre to $1.01/litre! My home is around 750SF, Moderately insulated with pink fluffy stuff, and I burn on average of 1425L of fuel per year.. Depending on the price of oil/winter temperatures that is anywhere from 1000-1500.
Any thoughts? Please let me know if I left out any useful information… My thoughts on pros are no more furnace upkeep, no more oil tank replacement, no more chimney (which currently leaks all around the flashing), time of day rates which I can really take advantage of! Cons are cost of the ETS unit upfront, and……?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
![](https://www.greenbuildingadvisor.com/app/themes/greenbuildingadvisor/dist/img/modules/detail-library/thumb1.png)
![](https://www.greenbuildingadvisor.com/app/themes/greenbuildingadvisor/dist/img/modules/detail-library/thumb2.png)
Replies
For GBA readers who are confused by Mark's question, here's what he left out:
1. "ETS" stands for "electric thermal storage unit."
2. Steffes Corp. is a manufacturer of electric thermal storage units. Here is the link.
3. These units are electric resistance heaters. If they are operated at night, using off-peak electricity, then can cost less than electric resistance heaters operating during the day, IF the homeowner has the ability to sign up for time-of-use billing.
4. Whether or not this makes economic sense depends (among many other factors) on the electric rates being offered by the local utility.
Mark,
No one can answer your question unless you tell us what nighttime electric rates are offered by your local utility to homeowners who sign up for time-of-use billing.
Here's some advice: if you aren't sure of the thermal performance of your home's envelope, you might want to invest in a home energy audit. Be sure that the auditor you choose comes with a blower door and an infrared camera.
Sorry Martin, the rates offered in my area (nova scotia, Canada) are 12cents/KWH, and 6 cents during off peak times. I tried to post the link to it, but it triggered the spam filter on here.
I had an energy audit done, but there was no infared camera in it. The air changes are were around the 16.5 mark, but I have done a fair bit of air sealing since then but have not had my blower door done for a second time.
Mark,
You burn an average of 1,425 liters of fuel oil a year at a cost of about $1,250.
1,425 liters = 376 gallons
376 gallons of fuel oil contains 52,218,469 BTU. If your furnace is 80% efficient, that provides you with 41,774,775 BTU of heat.
To get 41,744,775 BTU of heat from an electric resistance heater requires 12,240 kWh of electricity.
If you buy all your electricity at night, that much electricity will cost you $734. That's less than the $1,250 you are paying now. If you switch to electricity, you'll save $516 per year. Your investment of $3,140 will have a simple payback period of 6 years.
However, this entire analysis is based on unchanging energy costs. If electricity costs rise faster than oil costs, the switch makes less sense.
Here's your older question:
https://www.greenbuildingadvisor.com/community/forum/energy-efficiency-and-durability/20525/oil-forced-hot-air-vs-ets-room-unit
A high-efficiency heat pump just might be a better investment, especially if you run it off-peak.
The heat pumps and/or mini splits are a great idea but are simply out of my reach financially. These ETS units seem to be the cheapest way, especially since I get time of day use with it. NS power will only give you time of day use if you have some place to store the electricity (slab, ets unit, etc..). As I said now is the best time for me to consider it because I have to pay $1700 minimum if I keep my furnace. The pay back for an ETS unit seems that it will pay for itself rather quickly if you factor in the $1700 I would have spent anyway. Thanks for the help all!