Calculating the cost of heat?

[bank5]

That would probably work. But take a close look at other potential problems, especially water pipes in external walls, the garage, and in the crawlspace. The repair bill after one frozen/ruptured pipe would pay for a lot of electricity.

I should have mentioned that I live NC so I'm not too concerned about the pipes freezing. The average low for the coldest month is 30 degrees and high is 49 degrees.

 

[bank5]

Here's what I noticed after tracking it today.

Consumption w/ heat off: 2 kW per hour
Consumption w/ heat to bring it from 58 to 68 degrees: 16 kW (took 1.75 hours)
Consumption w/ heat stuck at 68 degrees: 5 kW per hour

So it took an extra ~8 kW to bring the heat up from 58 to 68 degrees compared to leaving it on constantly. To keep the heat constant consumes ~3 kW so leaving the heat off overnight is probably worth it.

These numbers are very rounded though and I've had some holiday cocktails so my math might be off

 

[REWahoo]

These numbers are very rounded though and I've had some holiday cocktails so my math might be off

One other consideration you need to factor in is the outside temp. Not sure what they were at the time you did your test but if your setback temp ends in the early AM when temps are at their lowest, it might take more than 1.75 hours to do the job.

EDIT: Plus, will your consumption actually be 2 kW per hour if you set the thermostat to 58? Once the temp drops to that level the heat pump will come on to keep it there.

Bottom line - I don't think your test results give you enough information to determine your savings.

 

[NW-Bound]

I agree with REW that while you might save some, you would need to repeat the experiment under the same conditions, with and without the set back, instead of extrapolating from the above observations.

My own solution is much simpler: I leave the thermostat for the central air fixed at 45degF year round, whether I am there or not. Given your moderate temperature, you do not need heating at all.


OK, OK! I admit, I do have to change from Bermuda shorts into long pants. And we do use a space heater for the master bedroom, plus an electric blanket to keep warm.


Before you start to call us Mr & Mrs Scrooge, I will hasten to add that we have passive solar heating, which does heat up the interior to 70-80 degF in the late afternoon. But it is true that even in the winter, I need to sleep with a small fan blowing a light breeze on my face.

 

[bank5]

One other consideration you need to factor in is the outside temp. Not sure what they were at the time you did your test but if your setback temp ends in the early AM when temps are at their lowest, it might take more than 1.75 hours to do the job.

EDIT: Plus, will your consumption actually be 2 kW per hour if you set the thermostat to 58? Once the temp drops to that level the heat pump will come on to keep it there.

Bottom line - I don't think your test results give you enough information to determine your savings.

Yeah, it's definitely not a definitive test. Just a rough estimate. The outside temp remained right around 46 degrees when I did the tests. Without the heat on, the indoor temperature of my house stayed at 58 degrees all day. I also tried not to use too much emergency heat during the set back (only increasing the heat a few degrees at a time). I'm planning on doing the setback tomorrow morning so it will be interested to how much energy is used then.

 

[NW-Bound]

I think I may save more money by using "alternative fuel heating". Specifically, I mean internal combustion of ethanol by ingestion method.

Seems like bank5 has had an early start on me, so I will get off my laptop now to head out to my bookshelf where my trusty bottle of Cognac is kept.

 

[RunningBum]

I should have mentioned that I live NC so I'm not too concerned about the pipes freezing. The average low for the coldest month is 30 degrees and high is 49 degrees.

I can remember a pipe freezing, in my Cary, NC, house once. It does get really cold once in awhile, and in many houses the pipes aren't protected well enough, so you should be at least aware of the possibility. Luckily I noticed it before the ice expanded and burst the pipe, and was able to put a space heater next to the kitchen sink and warm the pipes until they thawed.

 

[bank5]

I think I may save more money by using "alternative fuel heating". Specifically, I mean internal combustion of ethanol by ingestion method.

Seems like bank5 has had an early start on me, so I will get off my laptop now to head out to my bookshelf where my trusty bottle of Cognac is kept.

Here's a mulled wine recipe that we like to make around the holidays - Mulled Wine Recipe : Ina Garten : Food Network

It's not too high on the ethanol but does a good job heating you up.

 

[bank5]

I wound up picking up this one - Honeywell TH6220D1002 - Honeywell - FocusPRO Programmable Thermostat (2H/2C)

The setback doesn't use as much energy as I thought so I think it will pay for itself after a couple of months.

 

[NW-Bound]

Here's a mulled wine recipe that we like to make around the holidays - Mulled Wine Recipe : Ina Garten : Food Network

It's not too high on the ethanol but does a good job heating you up.

Ina Garten is a mellow and classy lady whose show on FoodTV I have watched a few times. Though I prefer my fuel in a high-octane grade (I actually only have 3 or 4 drinks a week ), I might try mulled wine some time, so my wife can join in; she does not drink at all. I would try without the honey first though. Seems like the apple cider would provide enough sweetness.

 

[brewer12345]

I am jealous of the low heating costs mentioned. We usually use between 500 and 600 gallons of heating oil a year. It is close to $3 a gallon this year, so...

 

[W2R]

I am jealous of the low heating costs mentioned. We usually use between 500 and 600 gallons of heating oil a year. It is close to $3 a gallon this year, so...

Let's see - - just to be aggravating, if I subtract my average summer natural gas usage from each month's natural gas usage, I come up with a total heating bill of $153 for the entire year of 2008 as opposed to your $1500-$1800.

This is not to say that post-Katrina New Orleans is the "poster child" for a low cost of living area, though. It is not, any more. Oh well. At least our heating bills are still low.

 

[Moemg]

I am jealous of the low heating costs mentioned. We usually use between 500 and 600 gallons of heating oil a year. It is close to $3 a gallon this year, so...

It is a trade off . My heating bills are almost non existent but my air conditioning bills make up for it .

 

[brewer12345]

It is a trade off . My heating bills are almost non existent but my air conditioning bills make up for it .

I get decent sized AC bills, too.

We will be relocating upon FIRE...

 

[W2R]

I get decent sized AC bills, too.

We will be relocating upon FIRE...

I think that is a really smart idea, if you can find a place with a lower cost of living where you would like to live in FIRE. Where are you thinking of relocating?

 

[NW-Bound]

I get decent sized AC bills, too.
We will be relocating upon FIRE...

And as I remember,a beefy real-estate tax bill too! I was shocked when I found out how high RE taxes are elsewhere outside of AZ. It is understandable if a state does not have income or sales taxes, but when they hit you with all of the possible taxes, I would have to wonder where it all went.

 

[brewer12345]

I think that is a really smart idea, if you can find a place with a lower cost of living where you would like to live in FIRE. Where are you thinking of relocating?

Very likely somewhere sunny out West. We really like CO (where DW grew up) and NM. In the intervening years, we will also investigate places like ID, eastern WA, possibly AZ, etc. Lower cost of living and a sunny climate are high on the list (the latter looms large in the winter as I am sliding further into SAD with each successive winter).

Yes, NW. My modest 3 bed, 2 bath house on a quarter acre in a middle class town runs me $8k/year in RE taxes (for a house that recently appraised at 360k). Price of admission for the largest labor market in the world for what I do. Eventually I will no longer need access to the labor market and it will not be worth the price.

 

[NW-Bound]

The tax you quoted is about 2.5 to 3X that in AZ.

Is the high RE tax peculiar to areas across the water from NYC?

I have been through NJ only twice and, knowing little about the state, do not imagine that the rest of NJ population would have an income level that high to afford the taxes.

 

[brewer12345]

The tax you quoted is about 2.5 to 3X that in AZ.

Is the high RE tax peculiar to areas across the water from NYC?

I have been through NJ only twice and, knowing little about the state, do not imagine that the rest of NJ population would have an income level that high to afford the taxes.

It is higher in some areas than others, but way above national average rE taxes are a feature of the entire state.