Insulation Definition and 128 Threads

I measure the temperature of metallic box using K thermocouple probe along with MAX6675IC to digitize its output. As soon as probe is placed in the cavity, the temperature drops to zero. I suspect that probe is being shorted with metallic box.Suggest some way to insulate the probe or suggest...

I have a high voltage source feeding a cable which is attached to the ceiling with plastic hooks, finally descending to the properly isolated source. The high voltage output is a typical terminal that the cable is connected to. When the supply is turned on, some spark like sounds emerge from...

I'm getting ready to winterize my home and was browsing the insulation aisle at Home Depot. They have a wide variety of insulating products from which to choose: soft foam, rigid foam, batts, etc. I got thinking it might be an interesting at-home experiment to confirm the R-values of some of...

I found this online calculator for insulation thickness: https://insulation.com.au/calculator/thickness-required/ Can you help me find equation being used for the calculation? Based on inputs required, my understanding is that it must be heat conduction calculations but also accounting for...

Hi! My cupper tubing from the heat pump via boiler room is not insulated. That makes it inefficient, because boiler room is unnecessary heated. I am looking at way to increase insulation and reduce heat loss. I already bought standard foam based tubing insulation. I hiked a lot and first aid...

Hello, My house has some heat loss. As an example I know the outside door temperature. How can I calculate the heat loss delta if I reduce the door temperature by 1 degree? I know that there is a formula to calculate a heat loss based on the U-value of a fabric. But I can't get those values...

I would like to test the insulation of a transformer using partial discharge analysis. Testing insulation between the primary and secondary is pretty straightforward. I short the primary as well as the secondary, apply voltage across the two, then take my measurements. I also need to test the...

A steel pipe with foam insulation is embedded in a concrete wall. The steel pipe is carrying cold water and therefore gains heat from outside atmosphere. Heat transfers through the concrete wall, foam insulation and then to the pipe. Is it possible to calculate critical radius of insulation for...

Hello, I usually wind induction motors. I found folding their insulation papers are so boring to me. So, I would like to make a machine that eases my job. Please see the attached file. The paper's dimension would be something like 80cm x 120cm. This machine must be able to fold the yellow areas...

Hi, I am trying to find the insulation resistance of a specific capacitor. I've posted on balancing resistors before and got some pretty helpful information. The previous datasheet gave the information in a different manner though. I'm hoping someone can help me decipher the insulation...

Does the shiny foil surface found on some panels rigid insulation serve as reflective insulation? If so, does the extensive printing often found on the foil degrade its value as reflective insulation or does it have no significant effect? (I think the main purpose of the foil is to be a vapor...

I'm wondering if the outside color has an influence on the thermal depletion of things such as a thermos, a wall, etc. Assuming, obviously, there's no sunlight hitting on them. It certainly has, but what difference percentage can we typically expect for example for bottles such as the ones on...

I am creating a blueprint for my future garden and I have been researching ways to naturally insulate plants for protection from cold and hot weather plus other necessities to create a flowing garden on a budget. If you have some ideas bring 'em on. I am open to a plethora of possibilities.

If a run of PEX water line needs to be periodically supported with pipe clips and also insulated, what's a good way to do this? - put the insulation over the pipe before clipping it and use clips for large diameter pipes?

I'm doing some experiments on heat insulation with a model house (made of styrofoam, 3cm), heated with a 25W light bulb. In some papers I have read that it's important for the box to be two-layered, with only the outer layer being styrofoam and the thin inner layer consisting of material with a...

Hello, I would like to ask you something about prevention from temperature equalization. I would really appreciate it if you can answer. To begin with, I want to store specific material into a breathable microfiber bag and place it inside a safe. This material is susceptible to heat and...

Hi, I'm working for a company that want me to calculate something for them. I haven't done physics since A level so have forgotten a lot of it and am now very stuck! They want to know the kWh per year they will be saving by reducing their heat loss (which they have given me in watts per meter)...

Good day all, I tried to solve the following exercise, I would be glad to get feedback for my attempt ( indeed I was puzzled by the numerical solution I got just need to check it for any mistake: A copper wire , 2mm in diameter and 100 m in length has an electrical resistance of 0,5 mΩ/m, the...

I need to buy most insulated jacket or snow coat at amazon or other online retailers (because it's not locally available). What materials are best insulator for snow or very cold weather? How do you select. What have you used that can even apply in Antarctica or in the mountain tops? I want to...

Hello, Can someone please tell me what the mean rating temperature in the tables provided in ASHRAE fundamentals, ASHRAE standard 90.1&90.2 for chilled water insulation indicates.

Homework Statement 2. The attic of your house will be vented to the outside and neither heated nor cooled. It will become relatively hot in summer and cold in winter. You will therefore need to put thick insulation in the attic floor to reduce heat flow between the air below that floor and air...

Supposed you have a box of size 1 square foot and the insulation is 100% efficient.. meaning there is no transfer of any heat outside.. and you put a lamp with glass surface temperature of say 50 Celsius (155 Fahrenheit). Would the air temperature in the box keep increasing... can it reach 1000...

In order to do some welding a long way from a power socket, I have made up a 200m long ‘extension lead’ from some 6mm2 armour cable. The cable is needed for another job later on. I have an test unit that: 1. Checks earth/ground bond with 8Vac and 25A. 2. Then measures insulation resistance...

I have Microsemi BR246-S0233. As is, the resistance between the X2 (GND) and signal line (e.g. A2) is OL. However, when I power it up (X1 = 25VDC), leave it for 5 minutes and power off, then straight away measure the resistance between X2 (GND) and the signal line A2, the resistance is now...

I read online that insulation rating of the conductor depends on the voltage rating and not on the current. Can some one explain me how current doesn't contribute to insulation rating? Am i missing something? Kindly explain me

Hi, In some marine isolated electrical systems I saw that only one phase insulation resistace is monitored. Why? If something happens on other phases I will have no information about that or...? Regards!

I want to rewind the stator winding of an automotive alternator. Want insulation materials I need for that ? Thanks for help Sam

This seems basic, but I'm stuck. Look at the attached picture. I'm trying to find the temperature on the outer surface of the insulation. Is it not possible because I do not know the rate of heat transfer? How do pipe designers know the required thickness of insulation needed to reduce to a...

Homework Statement A.[/B] Someone is walking outside when the temperature of the air is -10°C. The metabolic rate of walking is 140 Cal/m2hr, and the usual muscle efficiency (20%) applies. They are completely covered by clothing with a coefficient of thermal conductivity of 0.36 Cal-cm/m2hr...

Elsewhere someone is planning to install Under Floor Heating (UFH) in a house that is prone to flooding. UFH systems typically comprise a layer of insulation then a layer of concrete screed with UFH pipes in it. Given this recent news story...

Hallo, I have a question which elements are responsible for the increase of tangent delta in a X Capacitor and the reduction of its insulation resistance?

Hello everyone, From what i know electrical resistance for metals is a constant, but in fact it varies with temperature but not voltage. Explanation for metals and temperature is something like "heat, which is in fact average speed of electrons, does obstruct tranmission of other electrons...

If we apply an electrical insulating material on a bare conductor which carries 25 Kv AC Voltage. What would be the surface voltage observed on the insulating material? Is there any test/method by which surface voltage can be measured on the Insulating Material. The Insulating material has...

Hello! I was watching a video () about how extreme low temperatures are achieved in a D-Wave computer. As they explain, they have this series of cooling stages, each of which providing a temperature drop over the previous. I was wondering however, how could they avoid thermal propagation through...

Hello Physics Forum. I have to complete a solar water heater project for school and choosing between what would be better for the insulation of a tin reservoir. I'm leaning towards the glad wrap bag because it will let more light hit our reservoir. However it will be a quite windy day and cotton...

I have an object ( a windsurfer board) which I want to protect it from the cold but I cannot store it inside. The outside temperature now is a few degrees above 0 Celsius during the day, but is expected to drop to -8 at night for the next few days.. Assuming that during the day the board...

How does insulator's density affect its thermal conductivity? For example, considering such insulators as rock wool, It seems that the thermal conductivity should increase with an increase in density (due to elimination of 'air pockets'). However, experimental results, in many cases, look more...

Dear All, I'm seeking for EN/ISO/ASTM standards and where we can perform sound insulation testing for plastic foam/cellular products. Can you give me an advice? Thank in advance, Khoa

OK, sounds nutty in a limited short title, but... For a planned dome home in an area where average annual air temperature is 72 degrees, and thus steady state ground temperature at 20' deep or so stays within a pretty narrow range near that 72 degrees year round average above, and where house...

Hi, new here, with bits & pieces of basic college physics rattling around in my brain from years ago, so explain things at that level, please. I am building a cold frame in order to try growing food through the winter in NJ, USA. It will get below freezing here at night but not every day. I...

< Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown > What do you understand by the term "Critical thickness of Insulation"? What is the critical thickness of a plane wall? Derive an expression for the critical thickness of insulation for a...

Hi, Its been a while since I had my thermal heat transfer classes and I am a little skeptical on what I remember. Im trying to insulate a copper block, the sides are covered by an insulating material which has a low thermal conductivity (they are touching). Howver there is a surface on the top...

whats the thermal conductivity for car insulation? roof or dashboard, basically the thermal conductivity of foam used in most cars.

Hi, I was conducting an experiment under high voltage and the plastic insulation of my wire started melting, so I'm looking for an alternative insulation. The wire used needs to be insulated to prevent short-circuit. May I know if cloth-covered wirings are only insulated with cloth, or with a...

Could you tell me the physical reason, why the absorptive type sound insulation (Windowpane with some thickness) is effective only at high frequencies of sound source?

Hi, I currently have a project running involving dynamic insulation. I am struggling to develop a 1D transient analytical model to compare to my experimental results. I have used the separation by variables method in the most basic form over 1 solid material but have failed to adapt this to 3...

Hello, I am trying to calculate the effect of insulation and weather conditions on a cottage. The cottage is made from a timber frame while the panels are of 4mm plywood. The weather conditions vary throughout the year between 0 and 30 Celsius. Cottage is around 25 m2 with 2.2 m height, consider...

Does insulation affect electric and magnetic field?

I'm working on a problem involving steel structural members on the exterior of a building. I need to figure out how much insulation (for summer conditions) and possible heat tracing (for winter conditions) would be required to maintain minimum and maximum temperatures. I know I need to use the...

Homework Statement Hi guys, I have read this question over and over and have no idea where to start, would anyone be able to help. The Question Up to 20% of all heat lost in domestic dwellings occurs through walls. Many modern Australian homes are built by constructing walls...