# Tag Info

7

Because they're two completely different systems that have, in some circles, accidentally been given the same names. The things that are sometimes (particularly in the USA) called home geothermal systems are ground-source heat pumps. The energy for these comes from sunlight on the ground over the year. Electricity is used to move heat from a source ...

5

Split system air conditions (heat pumps) are refrigerator based systems. The two tubes you mention transport refrigerant from the compressor in the outdoor to unit to the indoor unit & return it from the indoor unit to the compressor in the outdoor unit, in a closed loop. Water is removed from the atmosphere by condensation, by the indoor unit. This ...

4

warm air can hold more moisture than cold air so the amount of water you can suspend in the air will change depending on where you install the humidifier. Mounting the humidifier before the heater will give you a final relative humidity below 100% after the heater. This can be important if you want to avoid dew. Mounting the heater before the humidifier ...

4

Many commercial hot water recirculation pumps will do that. Just grabbed one at random - Grundfoss Alpha1 15 40 130. I couldn't fetch the page after I ran their calculator. I used temp of 99C and head of 2m. 100C doesn't work in their calculator. Click link then click "view in product center", and fill in form. ALPHA1 circulator pump - heating, cooling, hot ...

4

Your last statement is basically correct: Another possible explanation is that the higher air temperature increases the air's water carrying capacity, which in the absence of an abundant water source, extracts water from your body faster. Therefore increasing perceived dryness. Heating air does "dry it out" in a practical sense. For example, a food ...

4

when the cogeneration plant switches of upon reaching 85°C flow and without another heat source, there's no way to reach 95°C. Are you sure the switch-off happens at 85°C flow, and not at 75°C return to the cogernetion plant(this is a typical value for Otto-cycle cogeneration plants for the emergency cooler to kick in)? If you have other heat sources and ...

3

If the heating element is constantly at 100°C, there is no way it can cause the room can get warmer than 100°C. Otherwise, perpetual motion machines would be possible. If you meant the heating element is providing a constant 100 Watts, then it is possible for the room to get to 1000°C with enough (meaning a lot) of insulation. Your copper building might ...

3

This is a heat transfer problem You can get a first order estimate by considering only conductive heat transfer, neglecting radiative and convective. Simplifying it even more, (again we don't know anything about your building, so this is the best we can do) q = k*dT where q is the RATE of heat transfer, dT is the temperature difference between outside ...

3

Heat loss due to conductivity of the walls of your container assuming the ambient outside temperature, $$\frac{\Delta Q}{\Delta t*A}=-k \frac{\Delta T}{\Delta x} =C_{constant}$$ In the above equation, the left part is heat loss per unit of area per second and the right side is the thermal conductivity, K multiplied by the temperature gradient which is ...

3

In a tank with no fluid movement and no heat source with steady ambient temperature, the temperature of fluid are layered strata roughly in onion layers but favoring the top of the tank, meaning the heat is gradually decreasing from the top in ellipsoid layers roughly following the geometry of the cylinder in you question, imagine inverte flames getting ...

3

When searching for 1100 watt heating tape, a number of returns match almost exactly the image you've provided. A few of the manufacturers provide NEMA separable molded plugs and also offer bare leads. The bare leads would be useful in this case, as you can add your own 90° banana plugs. To locate the correct plug, I used "right angle enclosed banana plug" ...

2

Your control logic appears to be sound. And with that logic, they could each be on separate simple thermostats if necessary. Just make sure all of your temperature sensors are sensing at the same location; or lots of craziness will happen. If you would like us to review your hydraulic plumbing you will need to attach a plumbing diagram. One important thing ...

2

You are confusing units, which is making your question difficult to understand. Electrical energy is measured in kW-hours (or Joules), not kW. If your heater consumed 500 W of power for 610 s, then you used 305 kJ of energy to heat your water. Similarly, if 10 l (10 kg) of water was raised by 24.2 °C, then it absorbed 4.186 \frac{J}{g ^\circ C} \...

2

A hot water based central heating system is fed by a pump and the only signal from the thermostat is heat/don't heat. The temperature regulation is done by duty cycling the pump so that when the temperature is low the pump will be started and when it's high the pump will be stopped. There will be some hysteresis of a few degrees to reduce the number of ...

2

Hydraulic separation in hydronic systems is generally more important with high flow resistance heat sources such as condensing boilers. If you don't hydraulically separate the heat source from the rest of the system, then you will have unnecessarily large pressure drops through your boiler. In order to have "complete" hydraulic separation, it is not ...

2

Recently I reviewed the technical specifications for a number of heat pumps (reverse cycle air conditioners) with a view to recommending one for purchase. The lowest outside temperature for a heat pump (reverse cycle air conditioner) to operate varies according to the manufacturer and the unit. According to the manufacturer's technical specifications, in ...

2

We have a test rig that works something like this, to heat up small objects (typically cubes of material with sides a few mm long) to about 1000C fairly quickly. The heat source is a "tube" of ordinary (and fairly cheap) tungsten-halogen car headlight bulbs surrounding the test piece, rated 12V 55W each, with home made parabolic reflectors covered in ...

2

I answered a similar question on SE Sustainable Living recently. Before anyone (including yourself) can answer your question you need to supply some more information. The first thing you need to find out & provide is, what is the heating value of the gas. In metric units this would be the mega joules (MJ) of heat that one cubic metre of gas produces. ...

2

An air conditioning system is basically a refrigerator, it passes air over a heat exchanger to cool it ie it injects cold air into a space, it doesn't 'suck' anything out'. The water which comes out of the waste pipe is just condensed water vapour from the incoming warm air, the waste heat form the exchanger goes elsewhere.

2

I have not used Kanthal, but I imagine it has similar properties to nicrome. Basically when you heat the wire up and cool it quickly, it quenches the wire. To reverse this process (or avoid it all together) you need to bring the metal to a specific temperature (without looking it up, red hot is plenty), hold it there for some amount of time, then slowly cool ...

2

To answer the question the way it's asked heating element of sort which is providing 100°C constantly but because room is totally insulated and shut can the temperature goes upto 1000°C or not ? No, this is not possible. A 100°C heater can't heat its surroundings above 100°C. Heat will not pass from cold part of the system to hot part of the system. ...

2

It is just getting as much heat as possible. Heat flows from hot to cold. The convection section is a much lower temperature. The convection section is basically waste heat in flue gas. The cold process fluid is (pre) heated to recover some of the waste heat. The exit process fluid may be hotter than the flue gas. In any heat exchanger you should ...

2

Automotive engines have their own inefficiencies. If the engine runs at its optimum speed, expect to convert ~30% of the energy in the fuel to motive power, 30% to heat in the cooling system and 30% to hot gases in the exhaust. At low loads, a petrol engine gets much worse figures, diesel scales a bit better. Reliability is not high enough. 20,000 miles ...

2

Would the pressures be the same with the fan On/Off? No. The pressure in front of the fan would be higher than that behind it - that is to say, the pressure would be highest at A, and then drop gradually around the loop B, D, C. Would it implode? No. - The pressure at C would be lower with the fan on than off, but in order to implode, the pressure would ...

2

Closed or not, a fan will always raise the pressure in front of it, and lower the pressure behind it. In order for the ducting to implode you would need a relatively strong vacuum. What is needed would be based on the rigidity of the ducting. However, a couple points that are important to remember: Its a closed system, so mass is conserved. Regardless ...

2

At least in the UK, domestic air source heat pumps are normally used to take heat from outside the house (cooling the air outside) and use it to heat water and/or the air inside the house. So the cooled air would go outside the house. If you use a heat pump the other way round to take heat from inside the house and put it outside then we call it air ...

2

In the diagram shown, then if the water temperature of the storage tank falls below the set value, the aux boiler comes in to augment the water temperature. Other possibilities include the use of a diverter valve so when the tank water temperature is too low, the valve changes to demand water heated by the boiler, if that boiler has a rapid response then ...

2

To summarize the comments given here: During the winter, the cold air outside can hold only a small amount of water in solution, which means it takes very little moisture in cold air to get it to 100% relative humidity. But then, when your furnace draws in some of that cold outside "makeup" air, it heats it up and its relative humidity then drops ...

2

Your basic logic is sound: You compare the case of the cogeneration plant + boiler vs. boiler alone. Your math looks correct to me. Where did you get the value 215 g/kWh from? All (german language!) sources I found give 202g/kWh for natural gas, which may well be because actual of differences in grid gas composition. When I do the math myself I arrive at ...

Only top voted, non community-wiki answers of a minimum length are eligible