Has anyone ever gave any thought to providing the dishwasher with hot water from boiler. I'm talking about not tempering it. The only reason I bring it up in this forum is because I would not consider it without the cheaper heated water. If your looking for a place to put that extra hot water why not sanitize your dishes with it. Our dishwasher has a sani wash and rinse cycle that just uses a electric heater to heat the water. Is there any reason this can't be done?
WAF increase
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Eric Johnson
Mod Emeritus
We don't temper our hot water. I mean, you can mix it at the tap or in the shower, but I don't have a tempering valve anywhere on the system. So yes, you can get 170-degree water in the dishwasher with no problem. The washing machine, too. If we had little kids in the house, I'd probably do something about it, but everybody is an adult, and we all like really hot water.
Nofossil
Moderator Emeritus
160 degree water for the dishwasher can save energy, because most dishwashers use their electric element to heat the water up to something near that temperature.
I'd be terrified of having water that hot out of my tap, though. 160 degrees will give you serious burns in an instant.
I'd be terrified of having water that hot out of my tap, though. 160 degrees will give you serious burns in an instant.
webbie
Seasoned Moderator
As NF says, you automatically get the savings by feeding any heated water to the SW (I think) because the electric element has to do less.
It wouldn't be to hard to run a dedicated line bypassing the tempering valve. You got me thinking.
leaddog
leaddog
There have been a bunch of threads lately that mull over saving electricity on appliances by helping them out with the wood boiler. I am waiting to see the pictures of somebodies boiler heated hot water bed or a "hydronic blanket" for bedtime! We use wood to help out in this regard now, by hanging our comforter in front of the wood stove for a few minutes before jumping in bed. Of course, the bedrooms in our current home are 50-55 degrees being so far from the stove...we won't have this situation anymore in the new home with the gasifier!
BrownianHeatingTech
Minister of Fire
Doing a bypass for the dishwasher is pretty common in modern houses. Clothes washer, too. In most cases where I piped something that way, I splurged on a second mixing valve, so there are actually two controlled hot water temperatures, rather than feeding "whatever the tank is at" to the dishwasher, in case of a tank overheat.
Joe
Joe
tuolumne said:
Excellent idea! I have a water bed, and am looking forward to getting my Kill-A-Watt in so I can see what a drain it is. Trying to talk the wife into switching from water to air because I'm tired of the electric element running 24 hours a day to maintain the temp. But, I can see how a few loops of that underfloor PEX tubing under the mattress with a dedicated tap to the water storage system, would work to put heat into the bed. You'd just need a way to regulate the temperature of the bed, probably an active thermostat that controlled a variable speed motor and that can pick up the temp from outside the bag. Maybe put the thermostat along the side of the mattress, at either the head or the foot, in the middle. Have it set so that when the thermostat gets too cold it runs the pump faster, and when it's too hot it shuts the pump off. This really wouldn't be that hard a feature to incorporate into a house. The only real disadvantage, you'd better make sure that where the bed goes is where you want it forever, unless you are willing to have water lines going along the wall or across the floor.
Joe I was thinking along your line of thought. putting tempering valves to make sure it doesn't go to crazy. I don't use hot to wash clothes very often so I don't think that would be to helpful.
BrownianHeatingTech
Minister of Fire
paulgrim1 said:
Hot water does get whites whiter, without the need for bleach (or with dramatically-reduced bleach usage).
We only use hot for whites and for diapers, but it does do a good job on those...
Joe
wdc1160
New Member
Can 160F water do damage to plastics and tupperstuff.
I have never messed with a dishwasher in my life. What temps are they typically throwing hot water at? I can see that this is heading towards me disassembling my washer to measure the heat it throws out.
I have never messed with a dishwasher in my life. What temps are they typically throwing hot water at? I can see that this is heading towards me disassembling my washer to measure the heat it throws out.
BrownianHeatingTech
Minister of Fire
ABGWD4U said:
Cheap plastics, yes. Better plastics will be fine.
Personally, I would set the dishwasher water at 150.
Joe
wdc1160
New Member
Did a water check. Actual temp out of the farthest sink facet was 120.0F +- .1 . I have found that I could leave my hand under this high pressure facet for about 7 seconds before pain set in. Clearly I didn't actually cause burns for this test purpose.
In the shower (next to the facet) I could put my shoulder under its highest heat for about 7 seconds. Also no injuries to date.
I think 160 would be instantaneous pain maybe a burn.
The water has to travel about 85 feet from the heater(unheated space) to the sink in a copper pipe. Shouldn't that cool down from 120 significantly. I was really surprised it registered that hot.
I decided to test a sink that is 20 pipe feet away from the hot water heater. The sink at that location also put out 120 F water. The only difference was the time it took to become 120.
Really thought the water would cood down after 85 feet of copper-- suprised by this.
In the shower (next to the facet) I could put my shoulder under its highest heat for about 7 seconds. Also no injuries to date.
I think 160 would be instantaneous pain maybe a burn.
The water has to travel about 85 feet from the heater(unheated space) to the sink in a copper pipe. Shouldn't that cool down from 120 significantly. I was really surprised it registered that hot.
I decided to test a sink that is 20 pipe feet away from the hot water heater. The sink at that location also put out 120 F water. The only difference was the time it took to become 120.
Really thought the water would cood down after 85 feet of copper-- suprised by this.
Probably best not to run boiler temp water to the 'panty tank', though I always thought it was a sink
http://www.accuratebuilding.com/images/services/charts/hot_water_burn_scalding_lrg.gif
"Most adults will suffer third-degree burns if exposed to 150 degree water for two seconds. Burns will also occur with a six-second exposure to 140 degree water or with a thirty second exposure to 130 degree water. Even if the temperature is 120 degrees, a five minute exposure could result in third-degree burns." Accurate Building
"Most adults will suffer third-degree burns if exposed to 150 degree water for two seconds. Burns will also occur with a six-second exposure to 140 degree water or with a thirty second exposure to 130 degree water. Even if the temperature is 120 degrees, a five minute exposure could result in third-degree burns." Accurate Building
Gooserider
Mod Emeritus
Market Survey Response - Mentioned the idea of running hot water to the clotheswasher and dishwasher to the GF, she was fine with the notion of running the hot water to the DW, but felt that she was quite happy with the temperature of the water in the clotheswasher the way it is - about 120*F max. She was expressing concern about the potential of water hotter than that damaging clothes. (Particularly bras which can contain significant amounts of elastic and (according to her) are easily damaged by heat)
She was somewhat amused by the idea of a hydronic waterbed, but didn't see any problem with it. I would think it would be easy enough to put pex under the mattress and then just treat it as another zone. However I will say that we have both used waterbeds in the past and weren't that impressed by them. We currently have a "Select Comfort" air mattress and love it - the adjustable firmness is great. We each set our own firmness for sleeping, or crank it up to max when we want to "exercise" %-P We also find that it is one of the best beds for not transferring motion, I don't feel it when she moves around and vice versa... We use an electric mattress pad on it which works really well.
Gooserider
She was somewhat amused by the idea of a hydronic waterbed, but didn't see any problem with it. I would think it would be easy enough to put pex under the mattress and then just treat it as another zone. However I will say that we have both used waterbeds in the past and weren't that impressed by them. We currently have a "Select Comfort" air mattress and love it - the adjustable firmness is great. We each set our own firmness for sleeping, or crank it up to max when we want to "exercise" %-P We also find that it is one of the best beds for not transferring motion, I don't feel it when she moves around and vice versa... We use an electric mattress pad on it which works really well.
Gooserider
Eric Johnson
Mod Emeritus
I kind of liked master of sparks' hydronic bed frame. You might want to keep the "exercise" to a minimum (or find another place to do it). Hate to spring a leak midway through your routine and have to abandon ship! Anybody else and I'd think it was a joke, but having seen some of his other projects, I suspect it is what he says it is. (Even I might put a tempering valve on this).
https://www.hearth.com/econtent/index.php/forums/viewthread/14578/
https://www.hearth.com/econtent/index.php/forums/viewthread/14578/
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BrownianHeatingTech
Minister of Fire
Gooserider said:
Quality washing machines tend to have automatic mixing systems, which avoids that problem.
Joe
Gooserider
Mod Emeritus
BrownianHeatingTech said:
Could be... However our machine is a basic box Kenmore, probably at least 14 years old, with three buttons for water temp, hot, warm and cold. On the back of the machine are two solenoid valves that the hoses connect to. Best I can tell from the way the water runs into the tub, is if you push cold you get one valve, hot the other, warm you get both... No fancy mixing that I can see... Maybe the newer machines have gotten fancier, though I'm not sure that's better as it means just one more thing to fail...
Gooserider
We had a hydronically heated water bed when my son was still at home. About 50 feet of PAP coiled under the bed, in the liner. A setpoint control turned on a zone valve like any other zone.
I run copper to the dishwasher IF you really want to run those high temperatures. Be sure the dishwasher is up to the task. i know commercial stainless steel dishwashers can take 160- 180F. I wonder about plastic ones?
hr
I run copper to the dishwasher IF you really want to run those high temperatures. Be sure the dishwasher is up to the task. i know commercial stainless steel dishwashers can take 160- 180F. I wonder about plastic ones?
hr
Redox
Minister of Fire
Finally, a topic I know something about! I used to fix appliances in a previous life.
A dishwasher needs about 140F in order to dissolve the detergent and most if not all dishwashers now have heaters to make this happen. Setting your water heater to 140F is more wasteful than letting the dishwasher heat it, due to the decrease in efficiency, unless you had an indirect heater right next to the machine. I ran a piece of 3/8" copper back to the water heater in our house because I found that after the first fill, the water in the pipe was cold again. Since most machines only use about 1 1/2 gal per fill, it was always getting cold water. I thought about a recirculation pump to keep the pipes warm, but this also comes at a price.
I thought about the waterbed when I finished the addition to the house and ran 1/2" CPVC stubbed out behind the bed, but it may take a while before I actually get around to hooking it up. Those heaters use a LOT of electric in a year. Most are around 300-350 watts and mine will go cold with less than 12-18 hours of run time. We have TOU metering and I shut mine off with a timer during the peak periods. It still uses about $15-30 a month. Make sure you put the blankets back on the bed after you are done "exercising".
I really like the copper framed bed! Does the water circulate over the top part possibly creating a burn hazard, or will conduction keep it warm? This should have instant WAF!
A dishwasher needs about 140F in order to dissolve the detergent and most if not all dishwashers now have heaters to make this happen. Setting your water heater to 140F is more wasteful than letting the dishwasher heat it, due to the decrease in efficiency, unless you had an indirect heater right next to the machine. I ran a piece of 3/8" copper back to the water heater in our house because I found that after the first fill, the water in the pipe was cold again. Since most machines only use about 1 1/2 gal per fill, it was always getting cold water. I thought about a recirculation pump to keep the pipes warm, but this also comes at a price.
I thought about the waterbed when I finished the addition to the house and ran 1/2" CPVC stubbed out behind the bed, but it may take a while before I actually get around to hooking it up. Those heaters use a LOT of electric in a year. Most are around 300-350 watts and mine will go cold with less than 12-18 hours of run time. We have TOU metering and I shut mine off with a timer during the peak periods. It still uses about $15-30 a month. Make sure you put the blankets back on the bed after you are done "exercising".
I really like the copper framed bed! Does the water circulate over the top part possibly creating a burn hazard, or will conduction keep it warm? This should have instant WAF!
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