Question:
I am very interested in conservation, green living, living independent of the grid, etc. Has anybody compiled a list of simple energy saving measures that have a reasonable return on investment (<5 years). I’d like to start spending a couple hundred dollars a month to upgrade my house. Getting my wife’s approval, and to really justify it to myself, I need to have confidence that it is a good investment. Anybody done any work on this? I have a 1600 sq. ft. house in central Texas. Standard 2×4 construction. Gas heat, waterheat, and stove. Already switching to compact flouresents as the incandesents burn out. No programmable thermostat but that is because my wife is at home with my daughter. I can get info for our water, electricity, and gas useage if anybody wants to lend a hand or advise. What would really be fun is implement some improvments that will save money in the long run with minimal impact on our lifestyle. My wife will be a reluctant partner in this effort so minimal impact on our lifestyle will be essential.
Response:
Jim Baber comments: > I am very interested in conservation, green living, living independent > of the grid, etc. Has anybody compiled a list of simple energy saving > measures that have a reasonable return on investment (<5 years).
Chris, You are very optimistic, those are good goals, but the idea of living independent of the grid is not very practical particularly in a short term ROI. The practical short term measures are conservation measures: 1 Change as many lights to florescent (use t8 florescent with electronic ballast) or the compact florescent bulbs to replace all incandescent bulbs 2 Insulate the house as much as you can to as high a R rating as you can, seal all the windows and doors as well as you can, (caulking is cheap and quite effective in stopping expensive drafts winter or summer) 3 In my home, built in 1954, replacing all the windows with dual pane and coated windows was effective, but quite expensive. If I had done the work myself, it would have been much cheaper, and I could have done it myself, had I known how simple a job it was. It was a lot easier than I had imagined, but you would need to watch someone do it once. 4 In this area, although daytime temps are over 100 frequently (98 days last year), since the evenings usually are under 75 by 10PM running a wholehouse fan or 2 is much better cost wise that my air conditioner. and you can get a good wholehouse fan for under $200. Mine saved about 7,500 kW last year by itself. Just don’t turn it on until it is cooler outside than in (they do sell neat differential thermostatic controls for this, but I look at 2 thermometers because I’m cheap). 5 Plant deciduous shade trees on the south and west side of the house. The leaves help the insulation in the summer, but are gone in the winter to let the sun help heat you. Also, if you are in one of the dry parts of Texas the summer transpiration through the leaves can raise the humidity around the house. As far as going off grid for power, I have to admit that I do not see any way that can be done in a short payback. I have a very good performing grid tied Solar PV system now, but my payback will be 6.2 years after I turned it on, and the grid tied systems are much as 1/3 cheaper than off grid. I have to be honest and add the only reason my payback is that good (and it is the best I am aware of), is because I am in California, and at the time I installed it the state had a $4.00 / W rebate (worth $40,000 to me) and the state also had a 15% income tax credit for the year installed. (worth a $6,000 reduction in my state income taxes) The size of the system is such that with the NET metering and the fact that we are on the Time Of Use rate structure, our power bill was reduced from $4,900 to less than $72. (this is a minimum hookup charge) We do still get about 21% of our power from the grid, but because the time of use metering is so advantageous to solar generation, we stay well ahead of the power company as far as $ are concerned. > like to start spending a couple hundred dollars a month to upgrade my > house. Getting my wife’s approval, and to really justify it to myself, > I need to have confidence that it is a good investment. Anybody done > any work on this? > I have a 1600 sq. ft. house in central Texas. Standard 2×4 > construction. Gas heat, waterheat, and stove. Already switching to > compact flouresents as the incandesents burn out. …….
My house is 2 separate building 16 ft apart totaling 4000 sq. ft. (A 1200 sq. ft mother in law house behind the main house) We have 3 central A/C units and are all electric except for heat. > thermostat but that is because my wife is at home with my daughter.
I am retired and am home most of the time, but I do use the setbacks, but not over 80 daytime summer or under 67 winter days, 63 for sleeping. (it hasn’t been above 50 here for 8 days in the 30s at night) The only reason I mention that is to correct some misconceptions about California. > I can get info for our water, electricity, and gas useage if anybody > wants to lend a hand or advise. > What would really be fun is implement some improvments that will save > money in the long run with minimal impact on our lifestyle. My wife > will be a reluctant partner in this effort so minimal impact on our > lifestyle will be essential.
Good luck, the WAF factor is important, the solar system took a 2 year sales approach, now she brags about it, but still kids me a lot about things like the astronaut recognition factor — Jim Baber 1350 W Mesa Ave. Fresno CA, 93711 (559) 435-9068 (559) 905-2204 (A no charge Verizon IN cellphone to other Verizon IN accounts) See our 10kW grid tied solar system at "www.baber.org"
Response:
Living here on Great Barrier Island (www.thebarrier.net), where we have no reticulated supplies of any kind, I can say with some authority that the most rapid energy saving measure is simply getting into the habit of using lights only when neccessary and always turning them off after you. The other habit to cultivate is always turning appliances off at the wall when not in use. If you have a freezer, run it through a timer so that it gets 3 1-hour on-cycles during the day and none at night. Televisions and computer monitors are energy soaks, esp. the latter. I’ve replaced all my comp. monitors with LCD screens for quite a dramatic saving in power. (But then I normally have 2 or 3 machiness running for several hours a day). Cheers, Charles – Hide quoted text — Show quoted text – > Jim Baber comments: > I am very interested in conservation, green living, living independent > of the grid, etc. Has anybody compiled a list of simple energy saving > measures that have a reasonable return on investment (<5 years). > Chris, You are very optimistic, those are good goals, but the idea of > living independent of the grid is not very practical particularly in a > short term ROI. > The practical short term measures are conservation measures: > 1 Change as many lights to florescent (use t8 florescent with > electronic ballast) or the compact florescent bulbs to replace all > incandescent bulbs > 2 Insulate the house as much as you can to as high a R rating as you > can, seal all the windows and doors as well as you can, (caulking is > cheap and quite effective in stopping expensive drafts winter or summer) > 3 In my home, built in 1954, replacing all the windows with dual pane > and coated windows was effective, but quite expensive. If I had done > the work myself, it would have been much cheaper, and I could have done > it myself, had I known how simple a job it was. It was a lot easier > than I had imagined, but you would need to watch someone do it once. > 4 In this area, although daytime temps are over 100 frequently (98 > days last year), since the evenings usually are under 75 by 10PM running > a wholehouse fan or 2 is much better cost wise that my air conditioner. > and you can get a good wholehouse fan for under $200. Mine saved about > 7,500 kW last year by itself. Just don’t turn it on until it is cooler > outside than in (they do sell neat differential thermostatic controls > for this, but I look at 2 thermometers because I’m cheap). > 5 Plant deciduous shade trees on the south and west side of the > house. The leaves help the insulation in the summer, but are gone in > the winter to let the sun help heat you. Also, if you are in one of the > dry parts of Texas the summer transpiration through the leaves can raise > the humidity around the house. > As far as going off grid for power, I have to admit that I do not see > any way that can be done in a short payback. I have a very good > performing grid tied Solar PV system now, but my payback will be 6.2 > years after I turned it on, and the grid tied systems are much as 1/3 > cheaper than off grid. > I have to be honest and add the only reason my payback is that good (and > it is the best I am aware of), is because I am in California, and at the > time I installed it the state had a $4.00 / W rebate (worth $40,000 to > me) and the state also had a 15% income tax credit for the year > installed. (worth a $6,000 reduction in my state income taxes) > The size of the system is such that with the NET metering and the fact > that we are on the Time Of Use rate structure, > our power bill was reduced from $4,900 to less than $72. (this is a > minimum hookup charge) We do still get about 21% of our power from the > grid, but because the time of use metering is so advantageous to solar > generation, we stay well ahead of the power company as far as $ are > concerned. > like to start spending a couple hundred dollars a month to upgrade my > house. Getting my wife’s approval, and to really justify it to myself, > I need to have confidence that it is a good investment. Anybody done > any work on this? > I have a 1600 sq. ft. house in central Texas. Standard 2×4 > construction. Gas heat, waterheat, and stove. Already switching to > compact flouresents as the incandesents burn out. ……. > My house is 2 separate building 16 ft apart totaling 4000 sq. ft. (A > 1200 sq. ft mother in law house behind the main house) We have 3 central > A/C units and are all electric except for heat. > thermostat but that is because my wife is at home with my daughter. > I am retired and am home most of the time, but I do use the setbacks, > but not over 80 daytime summer or under 67 winter days, 63 for sleeping. > (it hasn’t been above 50 here for 8 days in the 30s at night) The only > reason I mention that is to correct some misconceptions about California. > I can get info for our water, electricity, and gas useage if anybody > wants to lend a hand or advise. > What would really be fun is implement some improvments that will save > money in the long run with minimal impact on our lifestyle. My wife > will be a reluctant partner in this effort so minimal impact on our > lifestyle will be essential. > Good luck, the WAF factor is important, the solar system took a 2 year > sales approach, now she brags about it, but still kids me a lot about > things like the astronaut recognition factor
Response:
>I am very interested in conservation, green living, living independent >of the grid, etc. Has anybody compiled a list of simple energy saving >measures that have a reasonable return on investment (<5 years). I’d >like to start spending a couple hundred dollars a month to upgrade my >house. Getting my wife’s approval, and to really justify it to myself, >I need to have confidence that it is a good investment. Anybody done >any work on this?
What makes sense depends on many factors 1. What are your current costs of energy & consumption. 2. And what you think they may be in the future!! (This consideration can completely shift the balance.) >I have a 1600 sq. ft. house in central Texas. Standard 2×4 >construction. Gas heat, waterheat, and stove. Already switching to >compact flouresents as the incandesents burn out. No programmable
I would swap out the incandescent bulbs used for more than one hour a day immediately. If need be, swap them with compact fluorescent that you’ve already installed, but are used less frequently. >thermostat but that is because my wife is at home with my daughter.
Purchase a new thermostat anyway. A digital thermostat will be way more accurate than the old mercury based ones. Resulting in a more consistent house environment (comfort). I chose a lower end LUX brand thermostat, simple to use, with a large LCD temp readout. >I can get info for our water, electricity, and gas useage if anybody >wants to lend a hand or advise.
As for saving electricity … start out by measuring and looking for the energy wasters.. A "Kill-o-watt" meter is a handy tool for finding them. see http://www.contractor-books.com/P3/Kill-A-Watt.htm In one instance, I found that my SAT receiver and other A/V components (DVD/HDTV receiver/antenna rotor/antenna amp) were drawing significant amounts of power when shut off/idle. So, I connected them all to the switched AC outlet of my A/V surround sound amp/receiver. The A/V Surround sound amp/receiver draws less than one watt when turned off via remote control. Verses the ~40 watts for all the other items if they were left to connected to normal outlets. Centralize and place all battery chargers(cell phone/cordless drill/vac/etc) on switched outlet strip. Turn outlet strip on only when charging one of the batteries/appliances. Run of the mill PC’s and CRT monitors can be real power hogs. I’ve since switch most of my daily computer activities to laptops and LCD’s monitors. Here is a link to an archived post I made about using energy saving PC’s & LCD’s. http://groups-beta.google.com/group/alt.energy.homepower/msg/7bb8a21e… — If your existing refrigerators is more than seven years old, consider purchasing a new "energy star" rated unit, Note: Don’t always follow the energy star annual usage tags. They don’t always reflect typical use by the consumer. I.E. No provision for through the door ice dispenser, but is a big gain for the consumer since they don’t have to open the freezer door to get ice. Here is one my archived comments on the refrigerator selection. (Some researched details on how energy star ratings are measured.) http://groups-beta.google.com/group/alt.energy.homepower/msg/91fd2e30… Purchase a front loading washer. Frigidaire makes some reliable units. ~500$ range 1. Uses a fraction of the HW when compared to a top loader. 2. Final spin is much faster, resulting in dryer clothes which need less drying time/energy usage. 3. Can do really large loads. Comforters.. etc.. (also resulting in fewer loads if you plan properly. ) Here is a archived post made previously for front loader for potential front loader energy savings.. http://groups-beta.google.com/group/alt.energy.homepower/msg/f1ad773b… >What would really be fun is implement some improvments that will save >money in the long run with minimal impact on our lifestyle. My wife >will be a reluctant partner in this effort so minimal impact on our >lifestyle will be essential.
This is a small lifestyle change, but the savings can be significant and result better indoor air quality. Purchase an accurate indoor/outdoor digital thermometer. Open/close your screened doors, windows, drapes more frequently. Proper planing can significantly reduce the need for heating &cooling. Buy some box fans for spring/fall usage. For example, even though nighttime temps have dropped into the low 40’s, I have yet to turn on a heater this season. In the morning, I open drapes/blinds and catch the morning/afternoon sun. Close them when they no longer get direct sun. Similar actions apply when temps get warmer.. open windows at night, turn on fans to pull in cool night air, turn fans off and close windows in mid morning as temp raises. Then Coast through the heat of the day..
Response:
>I am very interested in conservation, green living, living independent >of the grid, etc. Has anybody compiled a list of simple energy saving >measures that have a reasonable return on investment (<5 years). I’d >like to start spending a couple hundred dollars a month to upgrade my >house. Getting my wife’s approval, and to really justify it to myself, >I need to have confidence that it is a good investment. Anybody done >any work on this?
What makes sense depends on many factors 1. What are your current costs of energy & consumption. 2. And what you think they may be in the future!! (This consideration can completely shift the balance.) >I have a 1600 sq. ft. house in central Texas. Standard 2×4 >construction. Gas heat, waterheat, and stove. Already switching to >compact flouresents as the incandesents burn out. No programmable
I would swap out the incandescent bulbs used for more than one hour a day immediately. If need be, swap them with compact fluorescent that you’ve already installed, but are used less frequently. >thermostat but that is because my wife is at home with my daughter.
Purchase a new thermostat anyway. A digital thermostat will be way more accurate than the old mercury based ones. Resulting in a more consistent house environment (comfort). I chose a lower end LUX brand thermostat, simple to use, with a large LCD temp readout. >I can get info for our water, electricity, and gas useage if anybody >wants to lend a hand or advise.
As for saving electricity … start out by measuring and looking for the energy wasters.. A "Kill-o-watt" meter is a handy tool for finding them. see http://www.contractor-books.com/P3/Kill-A-Watt.htm In one instance, I found that my SAT receiver and other A/V components (DVD/HDTV receiver/antenna rotor/antenna amp) were drawing significant amounts of power when shut off/idle. So, I connected them all to the switched AC outlet of my A/V surround sound amp/receiver. The A/V Surround sound amp/receiver draws less than one watt when turned off via remote control. Verses the ~40 watts for all the other items if they were left to connected to normal outlets. Centralize and place all battery chargers(cell phone/cordless drill/vac/etc) on switched outlet strip. Turn outlet strip on only when charging one of the batteries/appliances. Run of the mill PC’s and CRT monitors can be real power hogs. I’ve since switch most of my daily computer activities to laptops and LCD’s monitors. Here is a link to an archived post I made about using energy saving PC’s & LCD’s. http://groups-beta.google.com/group/alt.energy.homepower/msg/7bb8a21e… — If your existing refrigerators is more than seven years old, consider purchasing a new "energy star" rated unit, Note: Don’t always follow the energy star annual usage tags. They don’t always reflect typical use by the consumer. I.E. No provision for through the door ice dispenser, but is a big gain for the consumer since they don’t have to open the freezer door to get ice. Here is one my archived comments on the refrigerator selection. (Some researched details on how energy star ratings are measured.) http://groups-beta.google.com/group/alt.energy.homepower/msg/91fd2e30… Purchase a front loading washer. Frigidaire makes some reliable units. ~500$ range 1. Uses a fraction of the HW when compared to a top loader. 2. Final spin is much faster, resulting in dryer clothes which need less drying time/energy usage. 3. Can do really large loads. Comforters.. etc.. (also resulting in fewer loads if you plan properly. ) Here is a link to an archived post about potential energy savings using a front loading washing machine. http://groups-beta.google.com/group/alt.energy.homepower/msg/f1ad773b… >What would really be fun is implement some improvments that will save >money in the long run with minimal impact on our lifestyle. My wife >will be a reluctant partner in this effort so minimal impact on our >lifestyle will be essential.
This is a small lifestyle change, but the savings can be significant and result better indoor air quality. Purchase an accurate indoor/outdoor digital thermometer. Open/close your screened doors, windows, drapes more frequently. Proper planing can significantly reduce the need for heating &cooling. Buy some box fans for spring/fall usage. For example, even though nighttime temps have dropped into the low 40’s, I have yet to turn on a heater this season. In the morning, I open drapes/blinds and catch the morning/afternoon sun. Close them when they no longer get direct sun. Similar actions apply when temps get warmer.. open windows at night, turn on fans to pull in cool night air, turn fans off and close windows in mid morning as temp raises. Then Coast through the heat of the day..
Response:
Thank you, this is exactly the kind of info I am looking for. The kill-a-watt meter is perfect. I have been looking for something like it and the price is right. Using timers is a great idea. I have two PC’s that are off most of the time and two timers I bought to use when we are on vacation. I’ll put those on the PC’s immediately. That truly is a practical idea. I’ll get a kill-a-watt meter and start hunting down the most power hungry devices in the house and start dealing with them.
Response:
The single biggest bang for your buck, in the sub-decade ROI, is installing a Solar Domestic Hot Water system. Basically, heating all or part of your hot water needs with sun-absorbing panels. Most federal/state/provincial agencies tend to attribute 40% or more of your electricity/fuel consumption to that. Being where you are, nice sunny Texas, SDHW would be your first big step to getting a bit "greener". Not a "few hundred bucks a month" thing, though. Skip a few months, then plunk down the money for SDHW. There’s even quite a few DIY sites if you feel handy with plumbing. Other things, the powerbars to kill phantom loads, maybe changing out inefficient refrigeration, using electronic ballasts instead of magnetic ones or old incandescent lighting, sure, absolutely, do that. A watt saved is a watt saved. There’s lots of info on the net on SDHW, though, so take a look. I know that it won’t save you actual electricity costs, but we’re talking saving you MONEY, though, bottom line, aren’t we? SDHW will save you gas money. Best, DJ
Response:
>The single biggest bang for your buck, in the sub-decade ROI, is >installing a Solar Domestic Hot Water system…
IMO, if you need space heating, a home-built thermosyphoning air heater (a single layer of clear polycarbonate plastic over a darkened south wall with an air gap and vent holes (which might be partially opened windows) through the wall at the top and the bottom) and some thermal mass near the ceiling (with a large heater) would have a better payback. The air heater might cost $2/ft^2 and return $1/ft^2 per year. Nick
Response:
Replace lighting with CF’s Where appropriate. (all our lighting is CF) Place phantom loads (TV, Microwave, Transformers) on switched power strips. insulate doors and windows add rain rarrels to downspouts for lawn and garden irrigation. low flow faucets, shower heads, and toilets. high efficiency appliances Steve Spence Dir., Green Trust http://www.green-trust.org – Hide quoted text — Show quoted text – > I am very interested in conservation, green living, living independent > of the grid, etc. Has anybody compiled a list of simple energy saving > measures that have a reasonable return on investment (<5 years). I’d > like to start spending a couple hundred dollars a month to upgrade my > house. Getting my wife’s approval, and to really justify it to myself, > I need to have confidence that it is a good investment. Anybody done > any work on this? > I have a 1600 sq. ft. house in central Texas. Standard 2×4 > construction. Gas heat, waterheat, and stove. Already switching to > compact flouresents as the incandesents burn out. No programmable > thermostat but that is because my wife is at home with my daughter. > I can get info for our water, electricity, and gas useage if anybody > wants to lend a hand or advise. > What would really be fun is implement some improvments that will save > money in the long run with minimal impact on our lifestyle. My wife > will be a reluctant partner in this effort so minimal impact on our > lifestyle will be essential.
Response:
Hot Water Savings The key to hot water savings… eliminate the waiting. Every second a person spends waiting for hot water at their faucet / shower, your water heater is taking in "cold" city water. In addition to the lighting energy used while the person stands there waiting. A family of four waiting 1 minute for hot water spends around 97.3 hours every year "waiting". (Four people waiting 4 times per day, 365 days in a year, divided by 60 for total hrs) Include a lifestyle fudge factor and reduce it to 72 hours of "very cold" city water filling up your water heater needlessly. Let’s pause for a moment and imagine having to stand and watch a faucet waste water down the drain for 72 hrs. . . . Or consider a home which waits only 30 seconds…. that’s still 36 hours of watching water run down the drain. Install a RedyTemp Hot Water Recirculator, no dedicated return line required, idiot proof 10 minute "self-install". Behind the timer is a standard 3-prong wall outlet. Simply replace the timer with "The Clapper" set the clapper to the "away" mode. Now when the clapper hear’s someone in the bathroom it will auto start the circulation process. Or consider using the RedyTemp in the On-Demand mode using a wireless push-button. Simply replace the timer with a "wireless outlet control" similar to those used by the elderly when they don’t want to get up to turn on/off lamps. Press the wireless remote control from anywhere in your house (range 100-150ft) for no-wait hot water throughout your home. Return on investment estimated at two years for a family of four which waits an average of one minute for hot water. Install a tankless water heater for "endless" hot water and a RedyTemp for "no-wait" hot water. – Hide quoted text — Show quoted text – >Replace lighting with CF’s Where appropriate. (all our lighting is CF) >Place phantom loads (TV, Microwave, Transformers) on switched power strips. >insulate doors and windows >add rain rarrels to downspouts for lawn and garden irrigation. >low flow faucets, shower heads, and toilets. >high efficiency appliances >Steve Spence >Dir., Green Trust >http://www.green-trust.org > I am very interested in conservation, green living, living independent > of the grid, etc. Has anybody compiled a list of simple energy saving > measures that have a reasonable return on investment (<5 years). I’d > like to start spending a couple hundred dollars a month to upgrade my > house. Getting my wife’s approval, and to really justify it to myself, > I need to have confidence that it is a good investment. Anybody done > any work on this? > I have a 1600 sq. ft. house in central Texas. Standard 2×4 > construction. Gas heat, waterheat, and stove. Already switching to > compact flouresents as the incandesents burn out. No programmable > thermostat but that is because my wife is at home with my daughter. > I can get info for our water, electricity, and gas useage if anybody > wants to lend a hand or advise. > What would really be fun is implement some improvments that will save > money in the long run with minimal impact on our lifestyle. My wife > will be a reluctant partner in this effort so minimal impact on our > lifestyle will be essential.
Response:
> to the lighting energy used while the person stands there waiting. A > family of four waiting 1 minute for hot water spends around 97.3 hours > every year "waiting". (Four people waiting 4 times per day, 365 days > in a year, divided by 60 for total hrs) Include a lifestyle fudge > factor and reduce it to 72 hours of "very cold" city water filling up > your water heater needlessly.
Crock of crap, really. While waiting for the hot water for the shower, I use the cooler water to brush my teeth or rinse my eyeglasses. No wasted time, no wasted water. Same wit dishes. A quick rinse is OK for the cooler water too. — Ed http://pages.cthome.net/edhome/
Response:
- Hide quoted text — Show quoted text – > Hot Water Savings > The key to hot water savings… eliminate the waiting. > Every second a person spends waiting for hot water at their faucet / > shower, your water heater is taking in "cold" city water. In addition > to the lighting energy used while the person stands there waiting. A > family of four waiting 1 minute for hot water spends around 97.3 hours > every year "waiting". (Four people waiting 4 times per day, 365 days > in a year, divided by 60 for total hrs) Include a lifestyle fudge > factor and reduce it to 72 hours of "very cold" city water filling up > your water heater needlessly. Let’s pause for a moment and imagine > having to stand and watch a faucet waste water down the drain for 72 > hrs. . . . Or consider a home which waits only 30 seconds…. that’s > still 36 hours of watching water run down the drain.
The only time I wait for hot water is in the morning before I shave. And I’m not really waiting, the water is running while I’m taking a leak. And maybe I’ve wasted 4 gallons? At $0.005 per gallon, that’s $7.30 per year in wasted water. What’s my return on investment now? After the shave, the hot water is 4′ away from the shower head. By the time I turn on the shower and walk around the curtain (2 seconds) to get in, it is already up to temp. So that is zero wait time for me and maybe 4 gallons of wasted water. When I give my infant daughter a bath, I turn the water all the way to hot and rinse the tub with the cold water from the pipe. I’m done rinsing before the hot water get there but I close the stopper anyway. When the hot water finally gets to the tap, I let it run all the way hot for a few seconds to get the tub temp right and then turn the temp down and continue to fill. Then I put my daughter in. So no wasted water at all and no wasted time for my daugther’s bath. Let’s say I have two school aged kids. Most likely, they are taking showers back to back so the second child starts the water with the pipes already "hot". Same situation if two adults are getting ready for a work day in a separate bathroom. So suddenly a family of 4 with 4 waits per person per day for a total of 16 "waits" is reduced to 2 "waits". Actually I love the idea of a tankless water heater but for three very different reasons. There is basically zero savings from reduced water useage. It is calculable but negligible as I’ve described above. The three great things will be 1) the reduced energy bill because I’m not continually keeping 40 gallons of water hot (and stupidly using that 40 gallons to heat my Texas house or garage), 2) the reduced space requirements, and 3) the luxury of instant hot water if it can be installed close to the tap as a result of #2. What I’d like to do when I build my house is install the tankless water heater in a closet right next to the master bath. The kids and guests will have to rough it like we used to do in the old days and wait a minute for hot water. I’m the one paying the bills after all
Response:
"There is basically zero savings from reduced water useage. It is calculable but negligible as I’ve described above. " The issue isn’t the cost of the water that’s wasted, but rather the cost of heating the hot water that has to run from the water heater to the faucet every time you first need hot water. It takes quite a few gallons of water to flush out the cold water in the pipes and get the pipes warm. The longer the pipe run, the more energy that is wasted. A tankless unit saves that energy loss and it can be considerable.
Response:
> "There is basically zero savings from reduced water > useage. It is calculable but negligible as I’ve described above. " > The issue isn’t the cost of the water that’s wasted, but rather the > cost of heating the hot water that has to run from the water heater to > the faucet every time you first need hot water. It takes quite a few > gallons of water to flush out the cold water in the pipes and get the > pipes warm. The longer the pipe run, the more energy that is wasted. > A tankless unit saves that energy loss and it can be considerable.
If it takes ‘quite a few gallons’ to flush out the cold water then you are using pipes too big, and probably metal pipes as well. If you use 1/2" plastic pipe there is little cold water to flush out and little thermal mass to heat. — Free men own guns, slaves don’t www.geocities.com/CapitolHill/5357/
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Anyone ever put a neon light across the hot water heater element to actually observe when the hot water heater was operating? Whats the duty cycle with NO HOT WATER USE during the day? Is this calculatable given an R rating for the hw heater, and air and water temp?
Response:
- Hide quoted text — Show quoted text -> "There is basically zero savings from reduced water > useage. It is calculable but negligible as I’ve described above. " > The issue isn’t the cost of the water that’s wasted, but rather the > cost of heating the hot water that has to run from the water heater to > the faucet every time you first need hot water. It takes quite a few > gallons of water to flush out the cold water in the pipes and get the > pipes warm. The longer the pipe run, the more energy that is wasted. > A tankless unit saves that energy loss and it can be considerable. > If it takes ‘quite a few gallons’ to flush out the cold water then you > are using pipes too big, and probably metal pipes as well. If you use > 1/2" plastic pipe there is little cold water to flush out and little > thermal mass to heat.
That’s exactly what I was thinking as I waited for two gallons of cold water to flush through my pipes this morning. They’re plastic, but embedded in concrete (and I don’t think they’re insulated) and 3/4" – obviously, 1/2" pipe would have wasted less than half the hot water. — derek
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> "There is basically zero savings from reduced water > useage. It is calculable but negligible as I’ve described above. " > The issue isn’t the cost of the water that’s wasted, but rather the > cost of heating the hot water that has to run from the water heater to > the faucet every time you first need hot water. It takes quite a few > gallons of water to flush out the cold water in the pipes and get the > pipes warm. The longer the pipe run, the more energy that is wasted. > A tankless unit saves that energy loss and it can be considerable.
I hate to split hairs but the energy savings from the tankless is that you don’t keep 40 gallons of water hot and on standby. The energy used to fill flush the pipe is the same with either, unless you get the tankless close to the tap. Maybe that is what you are talking about. In that case, you would be right and I covered that advantage in the last paragraph of my previous post.
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> If it takes ‘quite a few gallons’ to flush out the cold water then you > are using pipes too big, and probably metal pipes as well. If you use > 1/2" plastic pipe there is little cold water to flush out and little > thermal mass to heat.
According to my calculations, a 1/2" I.D. pipe holds one gallon per 98 linear feet of pipe. So I was way off in my guess that I waste 4 gallons of water in the morning. The run from my water heater to the bathroom is no more than 40′. So I am wasting about 40% of one gallon. Check my calcs: 1 gallon = 231 cubic inches www.onlineconversion.com cross sectional area of a 1/2" I.D. pipe = pi * r^2 = 3.14 * 0.25 * 0.25 = 0.19625 square inches 231 cubic inches / 0.19625 square inches = 1177 inches = 98 feet A honkin’ 1" pipe would be one gallon per 24.5′. Even with that huge a pipe, I’d waste less than half the volume of water I guessed in my post yesterday.
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> If it takes ‘quite a few gallons’ to flush out the cold water then you > are using pipes too big, and probably metal pipes as well. If you use > 1/2" plastic pipe there is little cold water to flush out and little > thermal mass to heat.
1/2" plastic isn’t code around here for source lines unless that changed very recently, and 1/2" pipe for any length gives you crap for flow rate. I’ll stay with my 3/4" copper, thank you.
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> > If it takes ‘quite a few gallons’ to flush out the cold water then you > are using pipes too big, and probably metal pipes as well. If you use > 1/2" plastic pipe there is little cold water to flush out and little > thermal mass to heat. > 1/2" plastic isn’t code around here for source lines unless that changed > very recently, and 1/2" pipe for any length gives you crap for flow > rate. I’ll stay with my 3/4" copper, thank you.
3/4" I.D. is 43.5′ per gallon.
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> Anyone ever put a neon light across the hot water heater element to > actually observe when the hot water heater was operating? Whats the > duty cycle with NO HOT WATER USE during the day? Is this calculatable > given an R rating for the hw heater, and air and water temp?
I don’t know if your heater is elctric or gas. If it’s gas, you can hear the burner kick on and off. I’m guessing you are talking about electric. In that case, they make such a thing as a Kill-a-watt meter. It’s only made for 120V but it plugs into the wall between the outlet and the appliance and measures actual energy usage. I know the same sort of devices are made for 240V but they are probably all for industrial applications ($$$). I used one once to monitor the energy useage of a central AC unit. I was running an experiment on cooling the air around the outdoor unit with evaporative cooling while the unit was running. It made a significant difference in the energy useage. I was using those misters you can buy at Home Depot for cooling paios. The problem is that you need a really clean water source or the misters get fouled and you would eventually end up with scale build up on the AC coils. Not good.
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>…Whats the duty cycle with NO HOT WATER USE during the day? Is this >calculatable given an R rating for the hw heater, and air and water temp?
It’s estimatable. A 25 ft^2 50 gallon tank with R10 insulation and 110 F water in a 70 F room needs (110-70)50ft^2/R10 = 200 Btu/h, ie 59 watts, ie a 100×59/4500 = 1.3% duty cycle with a 4500 watt heater. Nick
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>1/2" plastic isn’t code around here for source lines…
CPVC may be, for hot water. >and 1/2" pipe for any length gives you crap for flow rate…
The Hazen-Williams equation says L’ of d" smooth pipe with a G gpm flow has a P = 0.0004227LG^1.852d^-4.871 psi pressure loss. L = 50′ and P = 40 psi makes G = 9.5 gpm for d = 1/2" pipe. Nick
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>>1/2" plastic isn’t code around here for source lines… > CPVC may be, for hot water. >and 1/2" pipe for any length gives you crap for flow rate… > The Hazen-Williams equation says L’ of d" smooth pipe with a G gpm flow > has a P = 0.0004227LG^1.852d^-4.871 psi pressure loss. L = 50′ and P = 40 > psi makes G = 9.5 gpm for d = 1/2" pipe.
What’s that in English? I _think_ it means I have to have over 40psi in my pipes to begin. Most well systems run about 40psi. — derek
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>>1/2" plastic isn’t code around here for source lines… > CPVC may be, for hot water.
Maybe. But, I really, really don’t like off-tastes in my water. I even have copper for my well piping rather than the (cheaper) plastic option. >and 1/2" pipe for any length gives you crap for flow rate… > The Hazen-Williams equation says L’ of d" smooth pipe with a G gpm flow has > a P = 0.0004227LG^1.852d^-4.871 psi pressure loss. L = 50′ and P = 40 psi > makes G = 9.5 gpm for d = 1/2" pipe.
OK, and the "personal observeations" equations show that I’m happy with my flow with 3/4" pipes until they go into the walls, the water is hot in a few seconds, and that in houses with bad flow, it’s invariably 1/2" pipe. Since there’s only one gallon of volume in 45′ of 3/4" pipe, what problem am I really solving by choking off my flow? – Hide quoted text — Show quoted text -> Nick
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