A small economy.

[NW-Bound]

... My reward for all this? Hmmm, let's see... the 6 bulbs ( 4 CFLs and two 4W night light bulbs to provide a resistive load for the old timer) add up to about 60W total, so one hour x 60W x 365 days/year is 21.9 kWh, or ~ drum roll...... $2.40 per year. Well, that's pretty anti-climatic. But it was a one time deal, so why not?

Hopefully, the set up will last so that you do not have to jump through hoops again to save $2.40/year.

Here's something I am pondering, when I dig down into my electric usage. Below is a chart showing the daily usage in a summer hot day that I already posted in a concurrent thread about solar energy. You can see the effect of the A/C starting to kick on at around 10AM, and it doesn't let off until 10PM. Actually the A/C runs on/off throughout the night on a hot day like this (minimum temperature still at 90F), but the duty cycle is lower during the night.



Anyway, look at the dollar chart, and one can see the shocking effect of the off-peak/on-peak difference in costs. It's the difference between 7.41c and 22.26c/kWh.

So, suppose I program the thermostat to cool the home down 1 deg in the hour preceding the rate change, then raise it back after the rate change. The precooling will delay the A/C running for a bit after the high rate kicks in.

I think the above will save me more than your $2.40/year.

 

[ERD50]

...

Anyway, look at the dollar chart, and one can see the shocking effect of the off-peak/on-peak difference in costs. It's the difference between 7.41c and 22.26c/kWh.

So, suppose I program the thermostat to cool the home down 1 deg in the hour preceding the rate change, then raise it back after the rate change. The precooling will delay the A/C running for a bit after the high rate kicks in.

I think the above will save me more than your $2.40/year.

I would definitely do that. I'd go as far as you can handle comfortably, like even 5 degrees cooler? Not only are the rates cheaper, but it is cooler in the AM meaning the A/C is running a bit more efficiently. You'll lose some of it, but at that rate difference I think it would pay off.

Now you need some of that phase change material, cool it in the AM and let it absorb heat from noon to seven.

What else can go on a timer? A fridge will stay cold for hours, but they aren't using anywhere near what A/C uses, but they are also kicking out heat that the A/C must pump back out again. Some industrial installations make ice at night, and use that for the next day's cooling.

Is a swamp cooler a possibility for you (as a supplement)? Or do water shortages limit that?

-ERD50

 

[NW-Bound]

I am doing 1 degree delta to start. I don't know about 5 degrees. When you are accustomed to cooler air, raising it in the afternoon will make it that much more miserable.

Swamp coolers are not too useful when we are in the monsoon season. When the air gets humid, a swamp cooler may cool the 115F air down to 85F, but loads it with humidity. An A/C dry output may be tolerable at 85F, but a swamp cooler output at 85F will make you miserable.

By the way, I keep mine at 78F around the clock, but am thinking about varying it +-1F.

 

[imoldernu]

Am not into the tech part of this, but the individual homes (now 79 of them) in our CCRC, each have three coach lamps... one on each side of the garage, and a pole lamp in front.
In our HOA benefits, maintenance of these lamps is included. Because of the location on the garage and the design of the lamps, replacement requires a ladder, and the dismantling of the top... a process that for just one light, takes at least five minutes... We had an unofficial "lamp patrol"... people who on their way home at night, would notify the HOA manager, who would then inform the maintenance group that a light had to be replaced. A separate trip for each bulb change.
Last year, the decision was made to replace all of the lamps with energy efficient bulbs.
I can only guess at the savings, but know that since the changeover, no bulbs have needed replacement.

 

[daylatedollarshort]

I don't know about lasting 22 years, but we started the switchover to LEDs a few years ago and have not had to replace a single one of them, which was not true at all for CFLs. I'm taking a pile of old CFLs to Home Depot today for household hazardous waste (mercury) recycling.

 

[Mulligan]

This sounds dumb, but it really has saved me some money ( or officially this year it will ). I got this idea from an internet article on energy costs. Last year I bought a window A/C unit for my bedroom. I like a cool house at night because I prefer a thick blanket when sleeping. Before I go to bed I turn house thermostat off and crank the bedroom unit up. The house naturally cools down slowly overnight while the bedroom stays ice cold. I figured about $25 a month savings in AC costs for the $100 unit. This year the savings goes into my wallet as it has paid for itself now.


Sent from my iPad using Tapatalk

 

[NW-Bound]

No, not dumb at all. I do that in the winter with a small electric heater in the master bedroom, and keep the central heat thermostat in my boondock home down to 45F. Yes, you get that right. 45F.

But for cooling, I am reluctant to hang window A/Cs for aesthetic appeal. And it is particularly tougher now that I have installed wonderful and expensive dual-pane low-E windows. I guess if I really want to, I can find a way to vent the exhaust of a portable free-standing A/C.

 

[Mulligan]

No, not dumb at all. I do that in the winter with a small electric heater in the master bedroom, and keep the central heat thermostat in my boondock home down to 45F. Yes, you get that right. 45F.

But for cooling, I am reluctant to hang window A/Cs for aesthetic appeal. And it is particularly tougher now that I have installed wonderful and expensive dual-pane low-E windows. I guess if I really want to, I can find a way to vent the exhaust of a portable free-standing A/C.

My bedroom window is facing woods in backyard. If it was a front facing window facing my cul de sac neighbors I would not have considered exposing myself to being such a cheapo!


Sent from my iPad using Tapatalk

 

[daylatedollarshort]

This sounds dumb, but it really has saved me some money ( or officially this year it will ). I got this idea from an internet article on energy costs. Last year I bought a window A/C unit for my bedroom. I like a cool house at night because I prefer a thick blanket when sleeping. Before I go to bed I turn house thermostat off and crank the bedroom unit up. The house naturally cools down slowly overnight while the bedroom stays ice cold. I figured about $25 a month savings in AC costs for the $100 unit. This year the savings goes into my wallet as it has paid for itself now.

It sounds smart. We don't have a good spot for a window A/C in the bedrooms, but maybe we should look at ceiling fans. I do have low energy room heaters flagged on Amazon to purchase before next winter. There is no point in heating the whole house overnight.

I bought a personal heater for one of the kids to use at work as they kept it kind of chilly, and it cranked out a surprising amount of heat for something like 300 watts or less.

 

[NW-Bound]

For heaters, radiant heat (infrared) falling on your skin will feel a lot warmer than the same amount of wattage that is used to heat the air. Other than that, any 300-watt heater will deliver the same 300 watts of heat into the room.

A/C's and refrigerators on the other hand vary in the amount of electric energy they use up in order to move the heat from a colder source to a hotter heat sink, i.e. fighting the natural heat flow.

 

[ERD50]

It sounds smart. We don't have a good spot for a window A/C in the bedrooms, but maybe we should look at ceiling fans. I do have low energy room heaters flagged on Amazon to purchase before next winter. There is no point in heating the whole house overnight.

I bought a personal heater for one of the kids to use at work as they kept it kind of chilly, and it cranked out a surprising amount of heat for something like 300 watts or less.

Agree on what NW-Bound said about electric heaters - watch out for claims of 'efficiency', or 'low energy use' (that just means low heat output), - other than the infrared effect, they are all the same. And watch out for that real scam where they claim that the oil-filled ones are better because they give off heat even after they turn off (yes, the heat they absorbed as they warmed up - no free lunch in the world of thermodynamics!). And of course, the ones made by the Amish are much better!

I'm curious if a window unit A/C or electric room heater makes sense - they might in some cases, I don't know. I considered the room heater by my computer, as it's just me in a big house all day, but the difference in paying for electric heat versus lower cost NG heat just didn't seem to provide any benefit, or maybe even a cost.

For A/C, make sure the vents are getting plenty of air flow to the room you want cooler (edit/add - a duct-booster fan might make sense?). A ceiling fan helps a lot, IMO. I'd say it provides the equivalent of ~3~ 4 degrees of thermostat setting. It also can help to keep the central air fan set to "ON" rather than "AUTO" - the blower fan will switch to a lower speed when the A/C cycles off, but that helps keep the cool air circulating. Our bedroom is upstairs, and this really helps, especially on not-so-hot nights - the thermostat is downstairs, so when the A/C cycles off, the cool air drops and keeps the A/C off, but the hot air rises to our bedroom. Circulating helps.

But a window unit could make sense I think, but it's hard to estimate just how much less the main unit would run, versus (I assume) a probably lower efficiency window unit. And the initial cost of the window unit, install it, the noise?

Those ductless units are becoming more popular, do they make sense? I haven't looked in a while, but IIRC, they are more aesthetic than a window unit, and the noisy compressor is outside.

-ERD50

 

[Mulligan]

Agree on what NW-Bound said about electric heaters - watch out for claims of 'efficiency', or 'low energy use' (that just means low heat output), - other than the infrared effect, they are all the same. And watch out for that real scam where they claim that the oil-filled ones are better because they give off heat even after they turn off (yes, the heat they absorbed as they warmed up - no free lunch in the world of thermodynamics!). And of course, the ones made by the Amish are much better!



I'm curious if a window unit A/C or electric room heater makes sense - they might in some cases, I don't know. I considered the room heater by my computer, as it's just me in a big house all day, but the difference in paying for electric heat versus lower cost NG heat just didn't seem to provide any benefit, or maybe even a cost.



For A/C, make sure the vents are getting plenty of air flow to the room you want cooler. A ceiling fan helps a lot, IMO. I'd say it provides the equivalent of ~3~ 4 degrees of thermostat setting. It also can help to keep the central air fan set to "ON" rather than "AUTO" - the blower fan will switch to a lower speed when the A/C cycles off, but that helps keep the cool air circulating. Our bedroom is upstairs, and this really helps, especially on not-so-hot nights - the thermostat is downstairs, so when the A/C cycles off, the cool air drops and keeps the A/C off, but the hot air rises to our bedroom. Circulating helps.



But a window unit could make sense I think, but it's hard to estimate just how much less the main unit would run, versus (I assume) a probably lower efficiency window unit. And the initial cost of the window unit, install it, the noise?



Those ductless units are becoming more popular, do they make sense? I haven't looked in a while, but IIRC, they are more aesthetic than a window unit, and the noisy compressor is outside.



-ERD50

It probably depends on the variables. For me it is cheaper, but I like sleeping room temp in mid 60s because I like a comforter blanket on. If I could sleep say in 73-74 degree temp like I have it on during the day I doubt it would be worth it. Im one of the few oddballs who would turn down the ac before going to bed from 74 to 67. If you like sleeping with a backgound noise, the window unit makes a perfect background noise. An article I read went into details of the math behind the 220 system versus one room 110 unit and showed a lot of savings to be had but of course those variables assumed had to be the variables you would need.


Sent from my iPad using Tapatalk

 

[NW-Bound]

I have looked at window ACs, and they are not bad at all in terms of efficiency, even the inexpensive ones. I have seen EER of at least 10, and that's not shabby. A small 5,000 BTU unit can keep a bedroom cool at night, and that takes only 500 Watts if running non-stop, compared to the central AC at several tons of cooling and many kWs. I just cannot find a nice way to mount one.

 

[Mulligan]

I have looked at window ACs, and they are not bad at all in terms of efficiency, even the inexpensive ones. I have seen EER of at least 10, and that's not shabby. A small 5,000 BTU unit can keep a bedroom cool at night, and that takes only 500 Watts if running non-stop, compared to the central AC at several tons of cooling and many kWs. I just cannot find a nice way to mount one.

I just pulled the top window down on it and pulled out its wings. Stuffed the perimeter with foam. Its appearance looks fine on the inside. On the outside it looks like a mountain zit on a teenagers forehead!


Sent from my iPad using Tapatalk

 

[NW-Bound]

I understand what you say, but that works for a narrower window, which opens vertically.

I am looking at my large bedroom window (6'W x 5'H) right now, the fancy dual-pane whose movable half slides sideways. Installing a window AC means having a big vertical opening that must be filled somehow, voiding all the wonderful insulating quality.

 

[Mulligan]

I understand what you say, but that works for a narrower window, which opens vertically.

I am looking at my large bedroom window (6'W x 5'H) right now, the fancy dual-pane whose movable half slides sideways. Installing a window AC means having a big vertical opening that must be filled somehow, voiding all the wonderful insulating quality.

Those are so fancy NW, I do not know what you are describing. If you can afford those windows, you can afford the 220 rumbling through the night without a window unit!


Sent from my iPad using Tapatalk

 

[NW-Bound]

Imagine a large window that opens sideways, like a glass patio door. Window ACs are not meant for them.

A smaller bedroom has two smaller vertical windows. I guess I can install an AC there, and move into it if another energy crisis hits.

 

[MooreBonds]

I understand what you say, but that works for a narrower window, which opens vertically.

I am looking at my large bedroom window (6'W x 5'H) right now, the fancy dual-pane whose movable half slides sideways. Installing a window AC means having a big vertical opening that must be filled somehow, voiding all the wonderful insulating quality.

They do have portable air conditioners....(aka a form of a dehumidifier)

Portable Air Conditioners - Air Conditioners - The Home Depot

 

[NW-Bound]

You still need to mount the hot air exhaust, which is typically mounted at a window that is partially opened. That vent mount is installed in the same manner that you mount a window AC, like Mulligan described.

 

[NW-Bound]

Speaking of windows, I just replaced 12 of 21 windows with the "fancy" low-E type. The other 9 are already dual-pane (but not low-E). Besides the superior insulating property, the windows also block all infrared. I still have blinds and shades on them, but these windows need no sunscreens. The house interior is brighter, and I need no light during the day.

I am waiting to see how much I will save on cooling/heating costs. The payback [-]may[/-] will take more than a decade, probably two.

PS. The nice thing about better windows is that they eliminate hot spots in the house near the windows, and the temperature inside is more uniform. And I already mention the better lighting through them.

 

[NW-Bound]

... look at the dollar chart, and one can see the shocking effect of the off-peak/on-peak difference in costs. It's the difference between 7.41c and 22.26c/kWh.

So, suppose I program the thermostat to cool the home down 1 deg in the hour preceding the rate change, then raise it back after the rate change. The precooling will delay the A/C running for a bit after the high rate kicks in.

As I made the above post, I just finished programming the thermostat to do what I thought of. And here's the result.

First, let me show you the dollar cost of the day before yesterday, 6/11/2015. The effect of the rate going from 7.41c to 22.26c at peak hours, a 3X increase, was quite dramatic.



Here's the consumption cost of yesterday, 6/12/2015, after I programmed the thermostat. See anything wrong?

 

[ERD50]

As I made the above post, I just finished programming the thermostat to do what I thought of. And here's the result.

First, let me show you the dollar cost of the day before yesterday, 6/11/2015. The effect of the rate going from 7.41c to 22.26c at peak hours, a 3X increase, was quite dramatic.

Here's the consumption cost of yesterday, 6/12/2015, after I programmed the thermostat. See anything wrong?

Hmmm, I assume weather and sunshine was roughly the same? And watch out for the shift in scales.

The increase before peak looks about as expected. The drop in peak is way more than expected. And what is the peak at ~ 9PM?

Was there some human intervention? Like, wow, it's cold in here, turn the thermostat up? Then later, wow, it's warm in here, turn the thermostat down?

At first I though maybe it was a weekday versus w/e thing, maybe different rates, but I see that is Thursday and Friday.

Do you have an answer, or do I need to update the "I don't know" thread?

-ERD50

 

[aja8888]

As I made the above post, I just finished programming the thermostat to do what I thought of. And here's the result.

First, let me show you the dollar cost of the day before yesterday, 6/11/2015. The effect of the rate going from 7.41c to 22.26c at peak hours, a 3X increase, was quite dramatic.



Here's the consumption cost of yesterday, 6/12/2015, after I programmed the thermostat. See anything wrong?

NW, just curious, but where are you getting the cost and usage data from?

 

[NW-Bound]

Heh heh heh... One just can't fool an engineer in technical matters...

The intention was as I described earlier: instead of 78F around the clock, decrease the temperature to 77F an hour before the rate increase to precool, then to go back to 78F at the rate increase. I would expect to save pennies a day, or a few dollars a year, something that just barely beats ERD50's $2.40/yr saving.

At about dinner time of 6 PM my wife complained that she felt hot. I thought it was warm, but assured her that it was just her. At 9 PM, she again complained of being hot. This time, I felt it too, so ran up to the thermostat upstairs to look. 85F. Holy cow! And the thermostat was in "override", meaning the normal program was interrupted and replaced with a fixed and manually entered 85.

How did that happen? I couldn't figure that out. To enter that mode required several button presses, and somehow I messed that up. Nobody else messed with that thermostat but me. Or did the thermostat hickup somehow?

Anyway, after I took it out of override mode, the AC ran non-stop for 1.5 hours to cool it back down to 78F. Hence, the peak at 9 to 10 PM.

Now, with this exercise, I learned that my AC consumes 5.8 kW, the 6.5 kW during that hour minus the "ambient" 0.7 kW due to the two fridges, fans, and lighting.

For a 5-ton AC, that's an EER of 10.3. I guess it's still OK for an AC that's 12-year old.

 

[NW-Bound]

AJA8888, the graphics were captured off the user's screen when I log on to my utility's Web account. They have smartmeters in my area that report hourly usage, and their Web site keeps that data going back 3 years.

This data is excellent, and I looked into it in detail just recently. The homeowner can study his usage pattern and learn a lot. For example, by comparing the 12-month costs before and after my pool pump change, I found out how much the variable-speed pump saves me a year ($260).