Questions tagged [heating-systems]

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8
votes
2answers
208 views

Heating circuit: Galvanized steel with press fitting vs welded steel pipes

What are the downsides for galvanized steel pipes + press fittings vs. welded steel pipes in a heating application? Diameter would be DN25/1". Background: The customer specifies only steel, only ...
6
votes
2answers
108 views

Heat transfer coefficient of a cylindrical hot water storage tank depending on its size

I have a simulation model of a cylindrical hot water storage tank. The heat loss is determined by the surface area and the heat transfer coefficient. A configuration of the storage tank with 900 ...
6
votes
2answers
181 views

Is it a problem to have two heat sources controlled for different temperatures on the same heating circuit?

This is the situation - I have three heat sources, called CHP, burner 1 and burner 2 on the same circuit. All three feed to the same heating manifold, with various heat demands. Preferably I want to ...
6
votes
2answers
197 views

Calculation of the stored energy for a heat storage tank

There is a heat storage tank that is directly loaded from the top and the heat is also taken from the top. The colder water from the heating circuit return flow enters the heat storage tank at the ...
5
votes
1answer
71 views

Calculation of the specific CO2 emission of a cogeneration plant for the produced electricity

Suppose I have a cogeneration plant that runs on natural gas and produces heat and electricity. The heat effeicieny is $\eta_{th} = 0.4$ and the electricity efficiency is $\eta_{el} = 0.4$. The ...
4
votes
3answers
150 views

Controlling the temperature with high precision

I need to control the temperature with high precision, and for this task would be good a temperature controller with pt-100 sensor, something like this one PID Temperature Controller ITC-100. As I see ...
4
votes
1answer
205 views

How to deal with thermal expansion in a city wide heating system?

How to deal with thermal expansion in a city wide heating system? Background: As part of the program to combat pollution in and around Beijing, my adopted city of Zhuozhou (population, over half ...
4
votes
1answer
744 views

Heat pump driven by a Stirling engine that requires no external work

I was considering some theoretical limits on transferring heat from one system at to another to another. It is well known that if you have two systems at temperatures $T_1$ and $T_2$, respectively, ...
4
votes
2answers
81 views

What surface temperature (rise) is required to (dis)qualify a combustion appliance from obtaining a “zero clearance to combustibles” rating?

How far must the surface temperature of a UL-listed combustion appliance rise to prohibit the manufacturer from specifying it for a zero clearance to combustibles installation? (I looked in UL 127 ...
4
votes
2answers
101 views

Analog PID controller - settings wrt $V_{err}$ - setpoint always higher than room temp

I designed from scratch an analog PID controller to mantain a temperature selected in the range of 60 to 80ºC with a room temp say = 20ºC. The "plant" is a simple 4R7 5 W resistor heated by a PWM-...
4
votes
1answer
112 views

What is the most common control method in Underfloor heating?

I am trying to research the common methods on an underfloor heating system that are available in the market. I know there are usually, On/Off control to control the flow of water into the pipe ...
3
votes
2answers
55 views

A humidifier before a heater and after a heater

What is the difference between installing a humidifier before a heater and after a heater?
3
votes
1answer
30 views

Question about flow temperature and storage temperature in a cogeneration plant

Let's assume I have a cogeneration plant that produces heat with a nominal output. The heat is given into a heat storage tank, which is filled from above. The maximum flow temperature of the ...
3
votes
2answers
109 views

Will circulating air within a sealed ductwork system cause it to implode?

Referring to the pasted in ductwork diagram, if an inline ventilation fan with a high CFM airflow was used to circulate air within a sealed ductwork system, would the fast moving airflow result in a ...
3
votes
2answers
118 views

Winding a wire heating element after a few uses

I bought recently 10 meters of Kanthal A1 AWG18 wire, which is a type of heating element (FeCrAl alloy). I intend to make a coil out of it, but it's no use doing that right now, I need more of it for ...
3
votes
2answers
60 views

At what (outside) temperatures is it efficient to run my windowbox heat pump?

I am an electrical engineer that took two semesters of Thermodynamics about 4 decades ago. I am aware of the theory behind the Carnot cycle and such. I live in a condo in the Boston area that is all-...
3
votes
2answers
54 views

Nickel Chromium Wire for high temperatures

I've been trying for months to find a way to heat moving air inside a tube to high temperatures. The closest to success I ever had was using an element from a heat gun. It would achieve the desired ...
3
votes
1answer
59 views

Is it better to heat a heat pump evaporator or the load directly?

I have a heat pump which moves heat from outside to inside. I also have a solar heating array that collects radiant heat from the sun. Given that my goal is to heat the inside (with minimal energy ...
2
votes
2answers
70 views

Why are home geothermal systems usable anywhere in the U.S. but industrial geothermal plants limited in geographical use?

Geothermal systems are used in regions across the U.S. for home use, but industrial geothermal plants are only used in areas where subteranian temperatures are very high. Why is this? https://en....
2
votes
1answer
57 views

Designing for a specific flowrate

I have a simple, practical engineering question. I'm trying to design a hot water circulation system with a constant flow rate of 1.3 L/min. I'm having trouble finding any pumps that will do the job ...
2
votes
1answer
75 views

Storage losses of a heat storage tank

Suppose I have a heat generator with a connected heat storage tank. If the heat generator remains the same and the heat storage tank is dimensioned larger, the running time of the heat generator ...
2
votes
3answers
144 views

Why not drive an air source heat pump domestic heating system with an auto engine?

Theses are my thoughts on the question. I can't find an answer to "why not?". It there something I am missing, or are auto manufacturers simply too focussed on cars only? The automotive industry has ...
2
votes
1answer
31 views

How to periodically shut down a recirculating hot water solar thermal system

I am posed with a scenario where a hot water solar thermal system has been setup. The system comprises of a cold water tank, heating arrays and then a hot water tank. The system is closed loop and ...
2
votes
1answer
42 views

Placement of supporting boiler in heating circuit

In my thesis, I deal with heating circuits, where several heat generators are present, e.g. a combined heat and power unit and a supporting boiler. Usually, the boiler is placed in front of the heat ...
2
votes
1answer
429 views

Hydraulic switch vs heat exchanger

In a heating circuit, there's two (known to me) ways to decouple primary flow (through heat source) and the secondary flows (to consumers): a hydraulic switch in the heating manifold complete ...
2
votes
1answer
38 views

Simulation of temperature in insulated box

I have a box outside that I want to insulate such that the temperature inside the box doesn't drop below 10°C given outside temperatures of (in the most extreme case - at night) -10°C. Inside the box ...
2
votes
0answers
14 views

What is the minimum height of a chimney needed in a camper?

Like a lot of people nowadays, I'm fitting a log fire into the back of a camper van but can't find the minimum height above the roof for the chimney. Ideally, it should be as low as possible for ...
2
votes
0answers
84 views

Why does a radiator valve require more torque after a few turns?

I'm automating a non-thermostatic household radiator valve, by replacing the knob with a DC motor and adding some support structure. You can see the system at work here: https://www.instagram.com/p/...
1
vote
2answers
69 views

Does a house heating system affect perceived and true indoor air humidity?

Does a house heating system affect indoor air humidity? Or to be more precise, does it affect your perception of how dry the air in the house feels (for instance dry is your mouth waking up)? (I ...
1
vote
1answer
29 views

How can Geothermal heat a home using the ~55 degree heat source of underground to a more usual 72 degree inside temperature?

It has bugged me for a while. If the earth is a constant 50-60-odd degrees several tens of feet beneath ground, and houses (I assume; ours at least does) don't drop down to lower than those ...
1
vote
2answers
39 views

Control power to a tungsten filament?

I'm afraid I'm completely out of my depth here. I would like to use a tungsten filament to radiatively heat something near to it (in vacuum). My issue is I cannot figure out the easiest and/or ...
1
vote
3answers
69 views

Cheap low-temperature oven

I'd like to make an oven for curing adhesives that require an elevated temperature for a proper cure. I'd like for the temperature to be settable from 60 degrees C to 75 C plus or minus 5 degrees over ...
1
vote
1answer
17 views

Fully saturated liquid and vapour

In terms of fully saturated vapour and liquid for water. Why in a real world heat pump cycle for example may the water not exactly reach these saturation lines as indicated in an ideal cycle?
1
vote
1answer
41 views

Solar Thermal heat gain formula converted to CO2e and trees saved

We have invented a solar thermal heating system with interseasonal storage, recently patented. I want to display the trees saved and carbon offset on the control display based on temperatures coming ...
1
vote
1answer
79 views

Why is gas pressure specified instead of mass flow?

Clarification: This question is all about the gas supply to the water heater. It has nothing to do with the water supply. My hot water heater specifies 5.5-10.5 W.C. (water column inches) of pressure....
1
vote
2answers
1k views

How to calculate thermal load?

basically I am trying to build an oven that we are going to use to cure prepreg carbon fiber. I found a company that can make it but they are requesting the termal load in order to continue. This is ...
1
vote
2answers
358 views

How to make water go into my house, from a lake without energy?

Basically, I'm thinking about a system, that filtrates, and makes a lake's water drinkable, drives water into my house's faucets without electricity, and all these should be able to work when it is -...
1
vote
1answer
71 views

Have there been successful attempts at using a computer's heat to warm something up? [duplicate]

Computers get hot. So usually we try to make them less hot. But what if instead of trying to cool down a computer we used that heat for something else? Not necessarily any thing big like a whole ...
1
vote
1answer
618 views

How does the Italian Percolator work?

This morning, as with every morning, I had my coffee. However, today it was burnt, because I slightly overfilled the water. I use an Italian Percolator on a gas top. Normally, you put it on to boil, ...
1
vote
1answer
195 views

Heating circuit - help me understand control scheme of return temperature

I'm looking at a P&ID of a heating circuit. The burner/boiler is non-modulating. Red is flow/hot, blue is return/cold. AFAIK the pump is fixed speed (no FI). As far as I understand the control ...
1
vote
0answers
22 views

Heat loss calculation and Energy Balance

The image shows the CAD model of the annealing zone in a galvanization simulator. The zone is electrically heated with a AC current of 5597A at 2.09V. This whole zone is surrounded by insulating ...
1
vote
2answers
32 views

Best way to create separate heating zone for basement

I have 2 heating zone in the house: one for the upper floor and one for main and basement. Both zones split from the main duct into their own ducts and use a damper to close/open. Now I want to ...
1
vote
0answers
7 views

Increase in target emission rate (TER) when using a air source heat pump (ASHP) in standard assessment procedure (SAP) calculation

I am running a SAP calculation on a proposed building which will be utilising a 8.5 kW ASHP for space and water heating. I am also running a comparative analysis against a mains gas boiler to show the ...
1
vote
0answers
17 views

Alternative to heater cartridge for 10mm deep hole?

In a design for a heated block I am working on I only have the space for a 6mm X 10mm hole for my heating element to be inserted into. Originally I had planned to use a 40W heater cartridge but the ...
1
vote
0answers
57 views

best refractory cement for embedded heating element furnace

first post I designed a 2000 watts 1000 degrees Celsius furnace with following chamber size: 11 cm length, 12 cm width and 15 cm depth. The refractory that I use is 1880 C high temp tabular alumina ...
1
vote
0answers
49 views

Search for comprehensive term for plants with heat generation with heat storage and operating states

My master thesis deals with systems with several operating states that generate heat and store it in a heat storage. Thereby I analyze combined heat and power plants with combustion engines, but also ...
1
vote
0answers
38 views

Where to put the booster pump at customer substation in a district heating system?

In a district heating system, one of the houses in the distribution net is not getting the desired heat into their house. This is because the pipes of this customer which connects them to the ...
1
vote
1answer
28 views

Operative Temperature in Underfloor Heating?

I am new to the Underfloor heating system, and a bit confused on the terminology for Operative Temperature. Is this the temperature that is measured by the sensor or is this the set-point temperature ...
1
vote
0answers
19 views

Safely evaporate electrolyte from fragile porous substrate

We have porous ceramic platelets of ~50x5x1 mm³ thickness infiltrated with ammonium nitrate solution (NH4NO3). We want to decompose and evaporate it w/o damaging the fragile substrate (decomposition ...
1
vote
0answers
2k views

What is the gray-body emissivity value of air

Wonder if anyone would know what is the average thermal emissivity value of air relative to blackbody at near room temperatures? I am looking for that magical number between 0 and 1. Looked everywhere ...