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Greenhouse Heating

Hi, does anyone have any suggestions on a cheap efficient Heating System I can build myself for a Greenhouse?

Topic by lamar850    |  last reply


Induction Heating

High frequency induction heating is basically a very efficient way to heat ferrous metals. Induction heating uses an powerful magnetic field to induce currents within the surface of the metal being heated. This means that the coil will not get hot unless the material being heated transfers heat to it. Induction heating is very efficient because no heat is wasted, no heat is wasted because the coil does not produce heat, the heat comes from the workpiece being heated only.

Topic by lyzyrdman    |  last reply


Efficiency contest

Disclaimer: I may be biased, since I have an entry in the running.I am very confused as to why the current leaders of the efficiency contest are in the contest at all, nevermind winning.One is not instructions for making anything. It just says "watch less TV". It may be good advice, but it is not a DIY project.One is a recipe for bread. It may be wonderful and delicious bread, but it has nothing to do with being green.One is about making a suit out of a sleeping bag. I suppose this would allow you to turn down the heat, but that is a bit of a stretch, (besides, so would a sweater - and the instructable doesn't say anything about this being the reasoning).I don't mean to disrespect these fine instructables, I am just saying they are totally irrelevant to this specific contest.But not only are they in the contest, they have been in 1st, 2nd and 3rd place since voting opened 2 days ago. Who is voting for these entries, and why?

Topic by JacobAziza    |  last reply


Stay Warmer At Night

We keep a kind of chilly house in winter . Sweaters and sweatshirts are expected, except for company.  In our area, we heat and cook with natural gas and that is cheaper than electricity. But the cheapest heat is residual from cooking . So a kettle is always on for tea whenever wished. And most nights we bake potatoes unless the daughter bakes brownies or something. And, in addition to that we will stick bricks in the oven. Come bedtime, the bricks get wrapped up in towels and put in the bed. where toes can cling to the brick and other toes. Best strategy for bricks is to bake them at 175 for a couple of hours.  Please spare the obvious comments, but please make other homey suggestions.

Topic by Wilmette    |  last reply


selective room heating?

I just turned on the heat before going into my room to go to bed. My roommate and I are in about one fourth of the whole house (and will be for about six hours), yet every room is being heated. This seems like a huge efficiency problem. Are there commercial systems out there that can heat selective rooms? If not, are there ways of making such a system? Can I just tape cardboard over the vents?

Topic by moisture    |  last reply


Heating Control

I have been thinking for some years now that I would like to have finer control over my central heating. The problem Now we are older we feel the cold more so in winter the heating is on all the time. This means that we have to keep altering the thermostat on each radiator at different times of the day or just leave them and so waste energy. One method means wasting energy but the other means rooms will be colder than we want initially.   The system and what i have We have a combination boiler which has a digital timer and also on the panel are temperature controls for hot water and radiator temperature. Each radiator has a thermostatic valve so each room can have it's temperature set independently. I have a computer which runs 24/7 and also a bit whacker which I can control via python code and electronics has been a hobby for over 50 years My idea I would like to have some system which would allow me to adjust each room temperature via computer control.   Possible solutions Solution 1 Fit a stepper motor to each thermostatic valve to adjust it at different times of the day/night. This would allow precise control but would be quite expensive to set up. Solution 2 Fit a small structure round each valve with a filament bulb or resistance wire in the bottom so that when power is applied to it then the temperature around the valve will rise and so the valve will close or, at least partially close. I think this would be much cheaper to implement but would have the small on-going cost of using power to the bulbs whenever the room temperature needs to be cooler that it would normally be. My initial plan Build a small structure around one of the valves with a low voltage bulb in it. It would have vents at top and bottom and so air would circulate. I have a portable digital thermometer so i could gather information and try different bulbs to see how much power would be needed and therefore what the on-going cost would be. Also try various shapes of structure to see what the effect would be.   So guys what do you think?

Topic by buteman    |  last reply


House hold heating? Answered

Like most UK houses my thermostat is in the coldest part of the house - The entrance hall. Although I have recently fitted thermostatic valves fitted to all radiators I can't help but feel the heating would be more effective if I simply controlled the temperature in the room we spend most time in during the evening- The lounge. I guess this would mean the rest of the house would be cooler than at present but that isn't really a problems for us. Is there any reason, anyone knows, not to do this? Has anyone gone down the smart thermostat route? https://nest.com/uk/thermostat/life-with-nest-thermostat/ New high efficiency condensing boiler Thermostatic radiator valves through the house High level of insulation to walls and roof. Double glazing all round in PVC frames.

Question by rickharris    |  last reply


Solar Heat in Cold Climates

Cool Energy is making a solar power and heating system that works in cold climates. Hooray!  It makes use of a highly efficient Stirling Engine.SolarHeart

Topic by whiteoakart  


Looking for Heat Resistant Flexible Material

I am trying to find a heat resistant material that is flexible... I am trying to make a pull down shade to attach to a tension rod, that will make my home more energy efficient... This means It will also need to be thin enough to roll up into a small roll... It needs to be reflective or at least block out all the sun... I work nights and sleep through the day, and have trouble sleeping when the sun gets through...

Topic by BadBobbo    |  last reply


Using body heat as a power source

You've heard of geo-thermal energy, but what about homeo-thermal energy? I know I sure haven't, mostly because I just made up that word :) Bad portmanteaus aside, what do you guys think of this concept? Running or charging things using the body heat you generate throughout the day and especially during the night. I'm not sure how plausible it actually is, or how efficient it is, but I thought it'd be a nice project to start working on and wanted to know what you guys think of it. Is it worth-while? Too complicated? Not scientific enough? I'm interested in your feedback! :)

Topic by kenizl86    |  last reply


CHALLENGE 60% efficient solar build

I would really love to see this Instructable be done but i don't have the technical background or resources to do so. It seems like a pretty easy build and looks like it can be done with common items. If the project is done correctly it should be a very powerful source of energy for free. It converts solar energy at 60% efficiency which is almost twice as much as current solar panels. It works by converting solar heat into electricity by heating hydride (which is hard to find but i think it can be replaced with a refridgerant) into a gas, which generates pressure to run a motor which runs a generator producing electricity and then the gas is converted back into the liquid state. The project will replicate Solar Powered Electric Generator Please contribute the time to building this it will pay off tons. Thanks To Everyone Who Helps.Mark

Topic by BTBAMYEAH    |  last reply


Induction Heating large scale

I am working on a project and have a large tank full of product kind of a greasy substance trying to heat up to temp of 180 degrees. the tank currently has a 4 inch pipe running inside wall all around tank for heat transference.. At this location a boiler is not a option at this time . I was curious if anyone ha s ever attempted a large induction heater build one that would encase a 4 inch pipe and heat liquid inside so thermal transfer would heat our product. Sorry for not including all details at this time i just curious if large induction heat was possible or efficient ?Thanks,

Question by andy1917  


Head/Pillow Heat Sink Materials

I'm wanting to build a heat sink for my head/pillow at night. The reason? My head frequently gets too hot at night giving me bad dreams, headaches, and sometimes keeping me up for hours. What I've come up with is steel or copper BBs contained in a thin plastic bag to prevent corrosion and enclosed in fabric for comfort and durability. Does anyone have a better idea, especially for the heat sink (metal) part?

Topic by Mazk    |  last reply


Night time Solar cooking

How would you like to cook with Solar power...after the sun went down?  It looks like MIT is on to something for the next step in Green tech. I found this idea very inspiring and it really makes the mind think of other uses beside just cooking after dark with the Sun. Think about useing this as a home heating device or water heater.  We could get millions of people off the electric grid with this type of invention if scaled up or engineered for the right useage. Any other ideas out there folks?

Topic by RedneckEngineer  


Vortex cooling / heating tubes

I am currently gathering information about vortex tubes for my repulsine project. There are plenty to choose from on a commercial base but I struggle to find any technical drawings with proper dimensions. Several home made varities can be found as well but wither with poor performance or incomplete drawings. So I was thinking that someone here either uses a commercial product at home or work and might be able to take some basic measurements for me? I am most interested in the relation between inner tube diameter and lenght for the hot and cold ends as well as the size for the vortex chamber itself. If there is an orifice used on the cold end the hole diameter would be required as well. My aim is, based on a properly working original, to create a device that might be less efficient but can be used without a compressor. Would like to see, correct transfer of dimensions given, a vortex tube like system was used in the repulsine. Some old documents state that there was a "seperator" which removed "heavy air particles" and created a temperature differencial between top cone of the repulsine and the wave disks.

Question by Downunder35m    |  last reply


Way Of Detecting Humans?

Is there ~~an easy way~~ a best way of detecting humans in the dark, or in a forest? Me and my friends play airsoft, usually in a forest, and it's hard to know where the enemy (other friends) are. I'm a sniper and I want an easy way to detect them. One way would be a thermo-camera, but those are expensive. Is there a better way?

Topic by guyfrom7up    |  last reply


Solar Power Towers Efficiently Using Brayton Cycle

I want to point out a solar to electric generation concept that has yet to be seen anywhere, even though it originated back during the Carter Administration's ERDA programs of the late 70's. I’m talking about solar power towers that convert solar energy into electricity at the hundreds of mega-watt level. While power towers do exist today, and the world currently does have a handful of them as shown in Fig-1, none use the Brayton Cycle nor can they boast an energy conversion efficiency at the mid to upper thirty percent level.  A group of engineers got together at a think tank organization called Sanders Associates in Nashua, N.H., several decades ago, and designed a unique Brayton Cycle, 100 MW solar Power Tower concept for generating electricity. This was accomplished under ERDA (Energy Research Development Administration) who gave us a phase-2 follow-up contract that took our phase-1 design and built a working scale model at the 10 KW level. This model was tested at the Georgia Tech Solar Research Facility and "registered" ~37% electric solar conversion efficiency. The system used ambient air as its working fluid, and was to be located in open-spaced desert regions. Phase-2 was lost to competition using a closed-loop liquid sodium system that boiled water into superheated steam at 900F to run a turbine that generated ~21% overall electric conversion efficiency.  Apparently, at that time ERDA would rather haul water out to the desert than use ambient air to generate electricity? The politics of their decision is beyond reason and clashes with improving the world’s development of green technology energy.  ERDA shut out our better technological performer and safely locked it away for another day! ERDA's official reason for turning us down: "this technology uses excessively high temperatures (2500F versus 900F) that are dangerous to workman maintaining the equipment". But that was back in the 70’s, maybe we’ve learned to deal with high-temp heat by now?   Solar Energy Concept Using Low Pressure Storage Our solar power tower would collect the sun’s energy by locating its ceramic heat exchanger on top of a tall tower as shown in Fig-1. The tower was located in the center of a field of active sun-searching mirrors (heliostats, Figure-2). These mirrors reflected sunlight onto our ceramic honeycomb heat exchanger, producing a concentrated flux intensity level that heated it to around 2500F. At the same time, low pressure fans generating only a few psi pressure would suck the ambient air through the honeycomb, heating it to just under the 2500F and then passing it through energy storage silos which stored the heat down to ~150F. We purposely designed the energy storage charging phase of our hot air system to work at only a few psi above ambient as a safety feature. The sun effectively acts as the combustor of our jet engine or Brayton cycle engine. Once the sun heats the air, it passes through heat exchangers consisting of a labyrinth of underground silos that are temperature segregated. These silos receive our 2300F airflow and cool it down to about 150F, transferring this heat into solid salt containers which turn to liquid once they have absorbed sufficient heat. Figure-3 is a schematic of this underground energy storage facility and shows the airflow being heated by a fully charged set of silos containing liquid salt-bricks. This airflow direction is reversed when we charge the silo’s salt-bricks. The bricks are kept in specially insulated, high pressure silos (located underground for added insulation) that store the heat energy at one atmosphere for later use. These underground silos act as our energy storage batteries, and when needed would discharge their heat energy accordingly into the moving airflow. This energy storage concept permitted the generation of electricity at night and during overcast days. Two sets of storage systems are required for continuous operation. One would be charging at low pressure while the other is discharging at high pressure through the Brayton engine to generate electricity.   Electric Energy Generation at High Pressure Electricity would be created by turning an electric generator at high speed. The generator was turned by running a jet engine connected to it.  The engine’s combustor for heating the air is effectively the sun, hence the name Brayton cycle for generating our solar electricity (Figure-4). The heat from the molten salt containers would increase the energy of the high pressure air coming from the compressor, and would then force it through a typical turbine that turns this energy into high rotational speed to run the generator and make electricity. Our solar jet engine sucks in ambient air using its compressor, as all jet engines do, and blows it through a series of silos at high pressure whose stacked bricks are held at different temperature levels. We start our airflow through a silo held as low as 150F and work our way up to ~2300F as we pass through our last, hottest silo which acts to complete the effective solar combustion process. This air preheating technique dramatically improves our energy turnover capability and allowed us to convert solar energy into electricity at near 37% efficiency. During our electric energy generation phase, the silos of our Brayton system requires operating at many atmospheres of pressure just as in any jet engine combustor using petroleum-based JP-fuel.      

Topic by RT-101    |  last reply


efficiency (not efficacy) of CPUs/computers? is all the power input technically converted into heat? Answered

It has recently been fairly hot where I live, especially in my room, where computer hardware seems to be increasing the temperature by a good 5-10*F over other rooms. This got me thinking, and was wondering if any computer engineers/physicists may know the answer to this one. If I am running a power-hungry intel CPU, coupled with RAM and maybe SSD storage (I wish!) is all the power fed into my system being converted into heat? In other words, if my rig consumes a good 250W-400W, and there are no transducer devices drawing power (LEDs or lights, speakers/microphones, monitors, motors, heaters, phone chargers, etc,) and all the energy is used for data collecting, and calculating, then is *ALL* the energy converted to 250W-400W of thermal energy (heat)? or do the data operations themselves in fact require energy and maybe entropy or something plays a role? where it would seem that 400W of input yields an apparent 399.981W of energy output + data.

Question by -max-    |  last reply


What is the fastest most energy efficient way to evaporate seawater on a small scale and collect the salt that reminds?

I tried standard sun evaporation in trays (1 gallon) and it takes far too long (not to mention all the debris that collects in the water during the evaporation process). Heating it over the stove uses too much energy. I am thinking a solar fan / heat combination. Your thoughts? (Note: The goal is to collect the sea salt.)

Question by ericrowe    |  last reply


Solar heating during the winter?

My hose is badly insulated and leaks everyhwere.And being a renal there is only so much I can do to fix certain issues.After looking at some modern designs for heat pumps in homes and how they claim to be able to provide hot water from the sun during the winter I started to wonder...Has anyone in colder climates a solor hot water thingy on their roof?I know hey work really great during the summr to keep the costs for hot water down but how do they perform at temperatures between 0 and 15°C ?How much water can they then still warm up and how quickly?Can you provide some real life numbers from your system, preferaby in above conditions or below thse temps?Why am I thinking about slor hot water systems in the winter ayway you wonder?Well, the Aussie sun still has a decent bite during the sunny winter times.Even on a 5° day the inside of yur car gets cosy warm quickly if you left it in the sun.I start my day in the middle of the night when most people turn arund and go for a few more hours.Means early bed times as well :(You see the problem ?You wake up and he house is freezing cold but it makes no sense to turn the heater on for the 30 inutes until you leave for work.Then you come home to a still freezing home and turn the heater on until you go to bed.Wouldn't it be great to be able get few more degrees inside by utilising a solar hot water system and a radiator in one of the rooms?....And with the entire "excess" of a solar hot water system one could even consider using the storage tank to get heated during the day to be used for a few hours when the sun is gone to give the real heater a break...Any thoughts or user experience with similar?

Question by Downunder35m    |  last reply


Car runs along at 376.59 mpg and gets a Guinness World Record

The funny thing is that this happened 35 years ago and the car that did it was from 1959. It's not exactly a consumer vehicle, but still impressive.Some info: - the vehicle was a 1959 Opel T-1 - interior completely stripped except for a plastic seat for the driver - top was chopped to lose drag - super-hard low-friction tires used - was driven at 30 mph - chain drive used to lose weight - the fuel line was insulated and heated so the gasoline entered the combustion chambers as lean vapor link

Topic by fungus amungus    |  last reply


World's most efficient solar dish? - MIT

A team led by Massachusetts Institute of Technology students last week successfully tested a prototype of what it says may be the "most cost-efficient solar-power system in the world," revolutionizing global energy production.The 12-foot-wide dish, made of a lightweight frame of thin aluminum tubing and mirror strips, concentrates sunlight by a factor of 1,000, according to the Cambridge, Mass., university. It can create heat intense enough to melt a bar of steel. More from ZDNet

Topic by Goodhart    |  last reply


Heating for outside battery storage compartment.

I have an idea for a wind powered outside LED light for the family's cabin. It would be on a pole and illuminate the pathway, just like a street light would do. So I wanted to have a battery in a box with my wind turbine charging the battery through the day and night. The problem is, it gets really cold sometimes like -36F / -38C and that would kill the battery. So, I also wanted to include some really small, simple heater inside the box. I'm having problems finding anything on what would be the best way to go about this. Wikipedia says heaters are made by resisting current. Are there special types of resisters you add to your DC current to create heat? Thoughts, suggestions, feedback are all welcome. Thanks.

Topic by horsebones    |  last reply


Reclaiming Wasted heat to make electricity

I work in an aluminum casting facility and we're looking for ways to save energy etc... one thing that we've got no shortage of is heat (during the summer the temp near the ceiling above the furnaces is over 230F) i've looked into stuff like they do in steel mills in Germany where they run pipes through the furnace linings and then use the heat from the furnace to make steam and run steam generators. but i was thinking of something else today. would you be able to just mount a bunch (or one huge) peltier exchanger (or whatever they're called) on the ceiling above the furnaces and use that to make electricity? i'm aware that they create electricity because of temperature differences (and not specifically from being hot or cold in general) so would we have to cool one side of the unit for maximum efficiency? are there any other ways that anyone knows of to turn waste heat directly or indirectly into electricity?

Topic by crapflinger    |  last reply


Where is the induction kettle or hot water system?

No modern kitchen these days is complete without at least a single induction cooktop.Convient to even place on the table to keep things warm but also nice to have 4 or 6 "hotplates" to cook on that are actually not getting hot at all.When it comes to efficiency induction cooking tops all others as no heat is wasted.Which brings me to the point...A single cooktop goes now often for well under 50 bucks.Although the base might end up slightly higher than a normal kettle I fail to see why we don't have induction kettles in our kitchen.Why wait 12 minutes to have the thing boil if you can do it cheaper and faster?Way more convinient too as there is no pesky contacts and heating elements anymore, no failure due to leaks either...But what really got me wondering is the hot water systems or heating options like prefered in Europe.Here you have a central "boiler" so to say and water circulates through valves into finned radiators, usually located under windows.We have oil filled radiators of this kind as free standing units that are now being phased out because they waste too much energy with their heating elements.Same story for just hot water :(On demand systems are getting more popular now outside Europe but still the common solution is to have a few hundret liters of water in a tank that is kept hot no matter how much of it we use.Be is gas or electric both types have their drawbacks and to get ahead of the corrosion that always kills them we now opt for expensive stainless steel tanks...Using induction it would be very easy to have a fully sealed tank and to actually only heat what needs to be heated without wasting too much energy.The "heating" element could be just a steel plate inside the tank with no connections to the outside.The gap between wall and element doubles to make the water circulate.And changing from a fixed timer to a temperatur control system to turn the induction element on and off is not hard either.Do you have an induction based hot water system, heater or maybe kettle already?Would love to see it...

Topic by Downunder35m    |  last reply


What is the best wire for generating heat? Answered

I am making an Instructable for some contests. The basic concept is below: -Put two peltier modules on each bloodline on the neck -Put small heat sinks that takes advantage of wind on the other sides of the peltier modules -Use the electricity generated by the peltier modules (While skiing in ~20F) on a heat-generating device located near the hands -Cover the parts that I can with some fabric and possibly build it into a neck warmer or face mask So my question here is: What kind of wire should I use to generate the heat on my hands? I'm looking for high-efficiency and fast to generate the heat Also, do you see any flaws in my concept that I should change? Lastly, the most important question I feel I should ask here is: Will the peltier modules generate enough electricity to make a significant difference on the heat of my hands? My hands get cold enough to hurt when I go back into room temperature if that helps.

Question by knexpert1700    |  last reply


How inefficient are resistors? Answered

I know how to calculate resistive losses, but do different types of resistors have different amounts of losses (power in vs power-out, in watts) From my own observations, connecting a 10 ohm resistor across a barrey will cause significant heating in both the resistor and battery, and cause the wires to get warm. All of this is resistive loss, but when I exchange the resistor for a 10k resistor, there is virtually no heating at all. What if I use a 0 ohm resistor (direct short). The only thing getting hot would be the power supply, due to internal resistance. Does this mean higher resistance is less lossy and by definition, more efficient, or is this simply due to the fact that there is less current flow, and less power loss, and efficiency (% of power loss)  With an ideal constant current source, will the losses though any resistive load be equal? ( X amount of watts lost/dissipated @ 1A) Is it possible to limit current like a resistor without losses? (I know PWM techniques are more efficient, but I want actual resistance rather than chopping current flow and filtering with an inductor/capacitor RC filter)

Question by -max-    |  last reply


Simple, efficient, low-cost, solar energy equipment

I am looking for a DIY simple, low-cost solar water heater and solar light that will work in any kind of weather and still be able to supply atleast some working heat and light. Please suggest.

Topic by rseni    |  last reply


Most efficient way to recover heat from 130 degree F water and transfer this heat to 140 degree F water?

I am making a solar still and I need to recover as much heat as I can from the 130 degree F water (bringing the water temp down to near ambient, 72 degrees F) and then transfer this heat to 140 degree F seawater. I have a limited amount of solar collectors to heat brackish water, send it through an evaporator tower and then a condenser tower to make fresh water. As the fresh water goes through the condenser it gains a great deal of latent heat, thus the 130 degree F water. In order to increase production and regain otherwise lost energy I am trying to recapture a portion of this heat to further warm up the brackish water (currently at 140 degrees after exiting the evaporator tower) before being further heated with the solar collectors. I am operating off grid, so the solution must utilize solar heat or PV panels as the power source.  Does anyone know of a heat pump that operates best in this temp range? What about using TEC (aka TEG, TEP or TEHP) to perform this task? Is there a better or more obvious solution that I am oblivious to? Any advice would be much appreciated. 

Question by MichaelMichael    |  last reply


Distribution of Solar Heated Water and Any Other Heated or Cooled Water

I started this project about a week ago after seeing the Instructable – https://www.instructables.com/id/How-to-build-a-strikeheliostatstrike-paraboliI made mine out of cardboard and then coated the cardboard – front and back – with fiberglass resin for stiffness. I covered the inside with tinfoil to test it out and find the focal point. It worked great with the focal point at the center of the dish even with the lip of the curve. I then removed the tinfoil and replaced the tinfoil with mirrored Plexiglas. Now it works awesome. I have a 30� parabolic mirror that can ignite wood almost instantaneously at the focal point of the light.Next I constructed the heating coil to run water through. This is made from a large 1 Kg coffee can, 16’ of ¼� copper tubing with end fittings, and the glass lid of a small sauce pan (handle removed). The outside of the coffee can is painted flat black as is the copper pipe. The copper pipe is coiled to a coil 4� in diameter and 6� in length and inserted inside the can with the ends extending from the side of the can through two drilled holes. The inside of the can is not painted, but left shiny. The glass lid is then taped over the hole with aluminum metal tape covering a minimum amount of the glass – about 1/4� around the edge.The coffee can is then suspended over the mouth of the parabolic mirror by a three point 6� chimney pipe stand-off. The can’s mouth is centered at the focal point of the mirror so all of the light being reflected by the mirror must enter the coffee can. Hoses are hooked up to the copper pipe fittings and these lines go to the feed/storage tank.The problem with the conventional set up from here is that the speed the water moves at (slow) to be heated to a great degree causes such great loses through convection, this system is not really feasible. I propose a new idea – or a new twist on an old idea.I noticed that the solar heat generating station use a black water pipe inside a glass vacuum tube to generate heat from the sun for heating water. I said to myself that this is a great idea and plan on building the next heating coil in a vacuum chamber. But, I also came up with the idea that the if the water is heated in this manner, why can’t it be transferred to the storage tank in a similar manner.If the feed lines were suspended inside a larger outer line and the outer line sealed tight and vacuumed the heat transfer due to convection would be almost nil. I estimated that with a total convective area at 100% the use of plastic stand-offs (8 @1/8� thick over 12’) the convective area would be reduced to 0.6%. Unbelievable! Even if this rose to 5% it is far beyond anything in use today by the home owner. Stretches of pipe going 100s of meters would no longer be un-heard of. You could place the dish in a close by field away from the trees and house and pump the heat back without losing it to the ground.This would also work for outdoor wood furnaces if use today. An outer pipe could be added over the existing pipe work, sealed, and vacuumed – almost all heat lose would be gone. And much larger stretches of pipe could be used here also. They would no longer need one furnace for the barn and another for the house. With this system, the pipes could even be run above ground, if desired, in some cases.This could also be used to replace insulation on cooling lines also.The key to the system is minimal contact between the inside and outside lines, and the vacuum between the two lines. Remember, there is no transfer of heat through convention within a vacuum, because there is no air for the heat to transfer through.As with all the new ideas this could get costly depending on the scale of piping you are dealing with – but the savings from reduced heat lose will far out way these cost in the near future.I may get an Instructable out for the Energy efficiency contest, but will be hard pressed.

Topic by strmrnnr    |  last reply


If LED lights bulbs are so efficient, then why do they have cooling fins? Answered

Most of the LED bulbs now sold as incandescent replacements have cooling heat sinks on them. If they have such great efficiency, I would expect minimal waste heat with no heat sink needed. Do they get too hot to touch as well?

Question by LongToe    |  last reply


Thoughts on this method to heat my pool? Answered

So, I have an intex easy-set 12' pool. We have finally leveled the ground and re-filled it and it works great. I live in Texas the swim season is pretty long already. I have this all rigged up with a bungee cord tether so I can swim in place for exercise. I dug out the center to give me another foot depth where I needed it. I also have a solar cover and the entire thing is covered by an elevated parachute tent for shade/wind block. (Also modesty). For now the water warms up significantly enough by about 10 am without much heat loss at night. I have thought long an hard and this is what I have come up with to heat it during the colder months. I can build a typical solar collector with hoses and hook it to either my saltwater sand pool pump or the cheapy pool pump it came with (which would be better?) then put it on top of a metal roof piece in the yard slightly elevated from rain water, then attach radiant floor heating mats underneath it. I am hoping this would provide a boost of heat on less sunny days or when it is significantly cold, like December. With a much cheaper energy bill. I am guessing I will need to insulate the heating things a bit or something. Feel free to suggest anything. I am just kinda in plan mode atm.

Question by HidiousTak    |  last reply


Energy efficient, waterless, Copper strip based cooling system

Energy efficient ,waterless Copper stripe based cooling system:The presented Idea is based on Heat exchange principle.As per sketch there will be a conveyor belt system and some copper stripes will be connected with this belt.Each copper strip will have a moveable hook.The conveyor belt will move with a motor.Each copper strip will be separated with each other and with conveyor belt with the help of Insulation (wooden insulation).Each copper strip will be connected with the machine for 15 to 20 seconds to absorb the heat and after that this copper strip will be removed and next copper strip will be ready to absorb the heat.The removed strip will be cooled down after some time and will be ready to couple with the machine again.In this way each copper stripe will work one by one to absorb the heat to cool the machine and each strip will get cool down due to convection .What I thought is that if I use a continuous water jet to cool the motor then the motor will remain cool so if I use the copper stripes then the same effect will be occured.It will work in this way that temperature will be not increased of machine if I couple the device with the machine. It will be low cost,low maintenance,waterless solution to cool the machines. It will consume almost nil energy

Topic by vikram_gupta11    |  last reply


Practical considerations when using transformer

Hi everybody! I basically love doing LED experiments and i was replacing many of the night lamps and stuff with simple LED circuits i made. Now i have few questions: 1) I generally use transformers to power them (230v/12v). Now apart from primary and secondary voltages and currents, are there any other ratings which i should consider? 2) I have made a portable night lamp with blue LED's. It has 4 arms in parallel and each arm consists of 3 LED's in series. All the arms are connected finally to a single 100 ohm resistor. Now as at most the whole setup might draw about 50mA of current. I had a transformer rated for about  500mA of secondary current, and so i used it with the setup. Will i have any issues using this? (Although i am sure i won't, but just in case anyway) 3)  Also, the transformer gets hot. How much temperature is in safe operating zone? The setup i used, after an hour, got pretty hot. I could barely hold it for a few seconds and i had to let go. Is it okay if it gets that hot?

Topic by charmquark    |  last reply


Im going to make a led lamp... I have the idea just need some help in how to go about making it

I have a glass candy looking sort of jar that i would like to flip over and build a small black circular stand to mount it on. Then frost the jar to give it a more ambiant looking light (i like blue leds but not necessary). I also need the lamp to be decently bright some where in-between a traditional desk lamp and a bright night light. I also and going to make a decal to stick to the outside of the jar to give it an illustration on the lamp. I dont want a battery operated one if possible id like a plug in with a switch or something. Something on the efficient side i don't like replacing batteries all the time, rechargeable may work. On that note i have a desk lamp already not sure what kind and brand i can check though, its a halogen i think it has a plug and a dial that brightens and dims it, i am willing to destroy if for this project that dial would be perfect . So what i need is recommendation on what and where to buy for lighting and details on how to mount it. I can handled most of the design of the arrangement, glass and decal im all over. More or less i need a cheap and decently easy way to light it im not super experienced in leds or a lot of wiring, im sure i can do it, would just be easier to avoid all of that.  Any help would be much appreciated 

Topic by amiller91    |  last reply


How practical is using bismuth for stovetop heat transfer? Answered

A stove that heats pots by induction is a nice idea, but it is still not common and will not work with all pots.Suppose, instead, the pot and resistive heating element were placed in a well that was filled with bismuth or another metal that has a low melting point. How would the efficiency of this compare to a pan sitting on an induction cooker, gas stove, or ordinary resistive heating element? What would be some important practical considerations, if this were implemented?

Question by NobodyInParticular    |  last reply


Heating options for hot bueing steel?

After moving house I am still living in a big mess of boxes that need to be unpacked, kitchen stuff be sorted and and so on... But with a big garage and proper workspace at hand it is also time to consider my options on how to create my tinker space. I would like set up a small forge later on if the landlord gives permission and that means bot blueing steel again. Which brings me to the problem of heating the nitrates :( My last setup was not only on a different continent but also totally oversized and powered by three big gas burners. This time I would like to go a bit smaller so I can use it inside the workshop. Was thinking of a max of around 8kg of nitrates that need to be heated in a safe way to melting point. Problem with that stuff is that it is not only highly corrosive but also requires quite some time and energy to melt. Using gas on such a small scale seems far to dangerous uless I include baffle plates and add several safe guards, so I would like to avoid the open flame approach here. Only reasonabe alternative that comes to my mind is electric heating. Did some small test last night outside :( Used a 2000W electric hotplate and an old stainless steel pot with about 1kg of nitrate in it. After 40 minutes there was still no real melting happening despited the entire thing padded and covered in glass wool. 20 minutes later I turned it all off and once cooled I found that only about 1cm of solid nitrate was at the bottom. If I would use a suitable container of let's say 20x10x10 cm as a small melting vessel: Could it be sufficient to use a 2000W nichrome heating element (with temp controller of course) in an insulated, forge like setup to melt the nitrate ina reasonable amount of time and be able to keep it that way once the steel is dropped in? Problem is the entire garage is already setup with power outlets and they all go to a single 10 amp breaker. I could max it out with 2400W but for obvious reasons would prefer to have some juice left for lights and other uses. If anyone here already made such a thing it would be great to hear how you solved the heating problem without waiting half a day for the stuff to melt.

Question by Downunder35m    |  last reply


where can I find cheap thermistor probes like those found in digital meat thermometers? Answered

I've seen people use a copper lead soldered to a wick rapped around a thermistor, but I really want to use something a little more efficient than this.

Question by Spaceman Spiff    |  last reply


anybody using on demand hydrogen to heat hot water?

Hello all - I am interested in either converting an existing gas-fired hot water heater to burn homemade hydrogen gas, or building an on demand heater powered by same. Is anybody doing this? What are the issues, beyond safety of making your own highly flammable gas? lol... I am thinking jet/hole size on the gas burner ring for efficiency considerations, corrosion issues, etc..... THanks in advance... Matt

Topic by concreteblue    |  last reply


Higher efficiency (high amp) 12V regulator alternative to 7812

I need a high efficiency 12V DC regulator to supply my thermoelectric modules (they're very inexpensive so I had no choice but to use them). I found that the modules are most efficient at 12V @ ~7A each. I could use many 7812s in parallel but they are too inefficient and too much energy is lost to heat. Is there any alternative? Electricity bills are going up so it'd be very good if I can find an extremely efficient step-down or step-up regulator, short of using an expensive 'gold standard' ATX PSU (which are usually upwards of 500W so the power savings don't matter).

Topic by arikyeo    |  last reply


what's a more efficient design electric motors or gas motors

Electric motors are more of the free floating bearing type than the gas motors friction bearing type not only that the electric motor can also replenish its power source but a gas motor cannot produce more gas only more heat requiring more complex sub- systems to allow it to operate. to modify the electric motor is inexpensive by its windings and magnet placing as opposed to a gas motors materials weight and shapes change performance thats why so many differnent engines are available    i think what matters most is the coolness factor we crave for ourselves to possess. [NEGATIVE]             [POSITIVE]          [-]                              [+] 1*  earth                          fire        wind                         water     [BLACK]                    [RED]

Topic by McRayGun  


Is it possible to do an easy 12v solar charger?

I want to build something for my dad. Basically I have: one car battery one 12v solar panel one or more computer fans And what I think would be useful to do is: have the solar panel to charge the battery and run the fan at the same time at day, and get the fan to run from the solar charged battery at night, is this easy to accomplish?  Levi

Question by Aqlor    |  last reply


Oldy transformer Wall Wart VS Swithing PSU more efficient? Answered

I mean whats the diffrence? I have bunch of the transformers and another bunch of the fully electronic kinds? why use one or the other? heat, efficiency, weight. BTW can i put a stepper motor to a 12v side of the transformer and maybe get some 110v on the other side or thats sounds crazy? thanks Al

Question by celalboz    |  last reply


How do I convert wind power or wind energy into heat?

I have access to a huge piece of windy  but south facing land,  solar gain will not be sufficient for heating green houses, barns, ect..., it is very cold and at high altitude (about 6500 feet).  Strong wind blows all the time.   How do i turn wind into heat and bank that heat as inexpensively and efficiently as possible.   space needed is no issue  the property is a half mile wide.  

Question by ztevo    |  last reply


How can you make a fridge more efficient? Uses of solar, heat exchangers, etc. Any ideas?

I was thinking of a heat exchanger, on one end a constant stream of cold well water, on the other end, the fridge coils. Or maybe use solar to cool it with peltier effect device? To keep it from coming on too often. Throw out any ideas, just though of this but have not seen it around, probably for a reason. It would be nice to use this idea at a cottage or camp eventually with little to no power, but at a cost worth building. The point would be to save money over the long run, so like a full blown solar would work, but it would cost a lot. Thanks again

Question by newinvestor23    |  last reply


Is it legal to camp one the beach for a night in Florida, Georgia, And South Carolina?

I am planning a sailing trip to the keys and wanted to know if it was legal to bring my canoe outrigger ashore and then pitch a tent while I heat a tasty can of beans up  :)

Question by ParacordJedi    |  last reply


How can I build an efficient thermoacoustic device with household materials? Answered

For a while now, I have been trying to build a thermoacoustic device with the following specs: -Can run with a temperature difference at around 100 degrees Celsius (ice on one end, boiling water on the other end, but it won't actually work with water) -uses normal air for the working fluid -constructed out of available household materials (or anything I can find at a hardware, office, or similar store) I have tried jamming coffee stirrers in a PVC pipe with copper wire serving as the heat sink, alternating layers of foil and two-sided tape, and for the third & recent attempt, newspaper jammed between two peg-boards (untested, but unlikely to work).

Question by Michael_Everett_Feder    |  last reply


Stirling AC, someone tell me why it wouldnt work.

Take a split type airconitioner unit (with heat exchanger / motor etc outside the house) remember that heat pumps have COPs >1 so they remove more energy than you put in. Now take a reasonably efficient stirling engine and bolt it onto the external heat exchanger so there is a gradient between the hot heat exchanger and the warm air outside and use it to pump the refrigerant around the system. Surely a heat-pump stirling engine combo can be made efficiently enough to effectively run itself once it has been started up, maybe with a few watts of electric to run some fans.

Topic by pyper    |  last reply


Solution to turning on/off gas: new pump design.

I've been working a couple weeks now on solving the problem I posted here on how to improve my pump design by alternating the feed of ethanol vapour. I got good feedback but ultimately all the solutions involved mechanisms which were going to be somewhat tricky to build and source, which is against the brief of the project I'm working on; being an open source solar tracker concentrator makeable from scrap. In the end I solved the problem by largely redesigning the whole pump. Since it's driven by boiling ethanol, rather than add an extra mechanism for turning the feed of vapour off and on, I reduced the amount of ethanol being boiled, so that it boils itself out after an appropriate period. The vapour is then able to collapse fully, which sucks in more liquid ethanol and refills the system. 1. At the bottom right is the boiler, which holds about 2-3 ml ethanol. 2. This boils and the vapour enters the 'chamber' (the half blue, half white (liquid and gas)), forcing out the liquid, which pours into the wheel, ending up in the main reservoir. 3. This continues until the eths in the boiler has boiled away to the extent that it can no longer overcome the rate of re-condensation in the chamber, which starts to suck, so to speak. 4. This draws liquid from the reservoir, which passes through the boiler, shutting off the boil, the pressure drops quickly and the chamber and boiler refill with liquid. 5. Two valves (the only moving parts, besides the wheel) keep all this going in the right direction. 6. Repeat. The wheel provides the motion for the solar tracker. It's not in by any means powerful or efficient, but the whole thing can be made from a bit of metal tube, some thin pipe, a glass jar and two valves from bike inner tubes (plus a paint tin, bike wheel bearing and some drinks cans for the wheel). I haven't had a chance to try it in the field yet, but powered by a candle it seems to work fairly well. Blog entry here, will post photos and videos when available.

Topic by SolarFlower_org  


How do I figure out the cost differential between turning on an inefficient furnace and using oil-filled space heaters? Answered

The big deal is that this furnace also heats the upstairs unit of a duplex, which i also own and rent out to my brother in law.  the deal is that he spends maybe 5 nights per week at his girlfriend's house.  so, if i turn on the furnace, all of the heat that goes upstairs will be wasted.  i'm interested in learning how to measure energy usage and learning how to determine the usage difference between running the furnace, which is about 50 years old and runs at about 50% efficiency and three pretty standard 7-fin oil-filled space heaters.  the flat in which i live is about 800 sq.ft. and the upstairs space is about 600 sq.ft.  the windows are old, but are covered with plastic shrink film for better insulation.

Question by hobbssamuelj    |  last reply