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I recall talking about ceiling mounted radiators? Easier to retrofit and don't get covered up by furniture.
Yes, likely easier to install. Another option is to install thin heating tubes in the walls embedded within the plaster.
"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."
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Going back to the older way of having walls radiating heat into the house.
You'd want to do this work at the same time as the other walls are being stripped for insulation I expect. I wonder if you could repurpose the underfloor heating kits to do it?
Use what is abundant and build to last
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The video at the link below is about an innovative drilling technique that might be of interest to someone thinking about ground level heat pumps. The invention is to use an "inchworm" technique to bore through the regolith.
https://www.youtube.com/watch?v=KlbfBrVAEH8
Costs ** should ** be less than if traditional long pipe drilling is used.
This method might even work on Mars, with a bit of adaptation.
Pretty clever. Swiss, of course.
(th)
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The link below points to an article on heat pumps published in 2023.
It features an innovation to improve efficiency.
https://getpocket.com/explore/item/how- … wtab-en-us
(th)
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It is a misconception that a heat pump is gaining enrgy from the earth as heat rather its using the loop to when producing heat the ground loop is sinking cold. when the air condition is on a blowing cold into the home it is sinking heat to the colder earth.
In the winter, a ground loop heat pump cycle draws low-grade heat from the earth. A fluid circulates through underground pipes, absorbing the ground's natural heat. This warm fluid transfers its heat to a refrigerant in the heat pump, which then becomes a very hot gas after being pressurized. A reversing valve sends this hot gas to an indoor heat exchanger, where the heat is released into the home's air distribution system.
Step-by-step cycle
Heat absorption:
In winter, an antifreeze fluid is pumped through the underground loop, absorbing the low-grade heat from the earth, which is warmer than the outside air.Heat transfer:
The warm fluid returns to the heat pump and transfers its heat to a refrigerant through a heat exchanger.
Compression: The refrigerant is then compressed, which significantly increases its temperature.Heat distribution:
A reversing valve directs the superheated refrigerant to an indoor heat exchanger coil. Here, the heat is transferred to the air, which is then circulated throughout the home via ductwork.Refrigerant expansion:
The refrigerant, now cooler, passes through an expansion device, drastically lowering its temperature and pressure.Cycle repeat:
The now cold refrigerant returns to the ground loop heat exchanger, ready to absorb more heat from the ground and repeat the cycle.
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AI Overview
An all-purpose heat pump refrigerant pressure and temperature (PT) chart is not available because the pressure-temperature relationship varies dramatically by refrigerant type. Instead, specific PT charts must be used for common refrigerants like R-410A, R-22, and R-134a.
The purpose of a PT chart
HVAC technicians use a PT chart to diagnose and troubleshoot a system by comparing the measured pressure to the saturation temperature of the refrigerant.
The chart applies to the saturated state, where both liquid and vapor refrigerant coexist.
By reading a pressure gauge and cross-referencing it with the chart for the correct refrigerant, a technician can confirm the system's boiling (evaporator) and condensing (condenser) temperatures.
During a system check, the chart is used to determine the correct superheat and subcooling levels, which helps confirm proper system function.
Pressure and temperature charts for common heat pump refrigerants
R-410A (Most modern heat pumps)
R-410A, sold under trade names like Puron, is a modern, high-pressure refrigerant used in most new heat pumps.[center]R-410A Refrigerant: Pressure-Temperature Chart[/center]
[table]
[tr]
[td]Temperature (°F)[/td]
[td]Pressure (PSIG)[/td]
[td]Temperature (°F)[/td]
[td]Pressure (PSIG)[/td]
[td]Temperature (°F)[/td]
[td]Pressure (PSIG)[/td]
[/tr]
[tr]
[td]-40[/td]
[td]11.6[/td]
[td]30[/td]
[td]96.8[/td]
[td]100[/td]
[td]317.0[/td]
[/tr]
[tr]
[td]-30[/td]
[td]22.5[/td]
[td]35[/td]
[td]107.0[/td]
[td]105[/td]
[td]340.0[/td]
[/tr]
[tr]
[td]-20[/td]
[td]36.8[/td]
[td]40[/td]
[td]118.0[/td]
[td]110[/td]
[td]365.0[/td]
[/tr]
[tr]
[td]-10[/td]
[td]55.2[/td]
[td]45[/td]
[td]130.0[/td]
[td]115[/td]
[td]391.0[/td]
[/tr]
[tr]
[td]0[/td]
[td]70.0[/td]
[td]50[/td]
[td]142.0[/td]
[td]120[/td]
[td]418.0[/td]
[/tr]
[tr]
[td]5[/td]
[td]78.3[/td]
[td]60[/td]
[td]170.0[/td]
[td]125[/td]
[td]446.0[/td]
[/tr]
[tr]
[td]10[/td]
[td]96.8[/td]
[td]70[/td]
[td]201.0[/td]
[td]130[/td]
[td]476.0[/td]
[/tr]
[tr]
[td]15[/td]
[td]96.8[/td]
[td]75[/td]
[td]217.0[/td]
[td]135[/td]
[td]507.0[/td]
[/tr]
[tr]
[td]20[/td]
[td]70.0[/td]
[td]80[/td]
[td]235.0[/td]
[td]140[/td]
[td]539.0[/td]
[/tr]
[tr]
[td]25[/td]
[td]87.3[/td]
[td]90[/td]
[td]274.0[/td]
[td]145[/td]
[td]573.0[/td]
[/tr]
[/table]How to use a P-T chart
Gather readings: With the heat pump running, use a manifold gauge set to measure the suction (low-side) and liquid (high-side) pressures.
Match pressure to temperature: Find the measured pressure on the chart and locate its corresponding temperature. This tells you the saturation temperature of the refrigerant in that part of the system.
Perform calculations: For instance, you can check the evaporator coil's saturation temperature against the air temperature entering it. The difference between these values indicates the superheat, which helps a technician assess the system's charge and cooling performance.
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Ground heat pumps (geothermal) are a promising concept for Mars settlements, using the relatively stable underground temperature of the regolith for efficient heating and cooling, supplementing solar/nuclear power, and can even be reversed to manage waste heat, though deep drilling for consistent heat is challenging initially, requiring significant infrastructure. While NASA currently lacks deep Mars data, shallow systems could exploit the day-night temperature swings, and larger, deep-drilled systems offer long-term potential for large-scale colonies, making them key for sustainable power and thermal management.
How it works on Mars
Heating: In winter or cold periods, heat is extracted from the ground (regolith) and transferred into habitats.
Cooling: In summer or during peak operation, the system can reverse, dumping waste heat into the ground to cool habitats.
Shallow vs. Deep: Shallow systems use the day-night temperature difference, while deeper systems tap into the planet's consistent internal heat, similar to Earth's geothermal systems.
Benefits for Mars settlements
Efficiency: Heat pumps are much more efficient than electrical resistance heating, using less power for the same thermal effect, according to a presentation at AAPG 2017.
Reduced Transport: Uses local resources (regolith) and electricity, reducing reliance on fuel imports from Earth, notes the AAPG presentation.
Waste Heat Management: Effectively uses waste heat from industrial processes or power generation, as discussed in a Reddit thread.
Reliability: Less affected by Martian dust storms that hinder solar power, as noted on the NASA Spaceflight Forum.
Challenges
Drilling: Deep drilling for consistent geothermal sources is technologically challenging and expensive for early colonies, though feasible for later-stage settlements, as pointed out in a Quora discussion.
Data Gap: NASA currently has limited data on Mars's internal thermal gradients, notes a NASA document.
Future potential
Geothermal is considered a vital long-term solution for large, self-sustaining Martian societies, potentially alongside solar and nuclear power, states a Utah FORGE article.
A ground heat pump system for a 200-meter diameter, 120-meter tall Mars settlement dome would serve primarily as a high-capacity, long-term thermal management system rather than a standard HVAC unit, leveraging the high insulating capacity of Martian regolith to maintain comfortable internal temperatures (approx. 20°C) against an average ambient temperature of -63°C. Due to the immense heat loss to the cold Mars environment, this system would likely require over 1 MW of heating power, with the ground acting as both a heat source and a heat sink.
Key Technical Considerations
Heat Loss and Power Needs: A 200m dome (volume ~83 million m³) has massive surface area, requiring substantial energy to prevent heat loss, with estimates exceeding 100 MW of heating during, for instance, a cold winter night.
Regolith as Insulation: Martian regolith is a poor thermal conductor (approx. 0.039 W/(m·K)), which is beneficial, as it acts as a natural insulator when used to cover or bury portions of the dome.
Subsurface Temperatures: While surface temperatures fluctuate wildly (-153°C to 20°C), deep underground temperatures on Mars are generally below the freezing point of water, requiring the heat pump to manage a large, constant temperature differential.
System Design (BTES): A Borehole Thermal Energy Storage (BTES) system, involving a series of U-tube pipes connected in a closed-loop and drilled 50–200m deep, would be necessary to transfer heat between the habitat and the deep ground.
Operational Strategy
Thermal Regulation: The system would likely operate as a water-to-water heat pump to deliver radiant, in-floor heating at the ground level, maintaining a stable temperature.
Waste Heat Usage: The heat pumps can be used in tandem with nuclear reactor waste heat (approx. 210 kW of thermal energy per 40 kWe reactor) to warm the surrounding regolith barrier, which helps keep the dome insulated.
Thermal Conductivity Management: The system would need to ensure the ground remains frozen outside the dome to prevent the leakage of liquid water or air through the soil, using the ice as a natural sealant.
Advantages and Challenges
Advantage - Efficiency: Ground source systems provide high efficiency, potentially reducing energy demand by 25-50% compared to conventional, less efficient systems.
Challenge - Installation: Drilling deep boreholes in Martian soil requires robust, heavy-duty mining equipment that must be brought from Earth or constructed locally.
Alternative: Given the high energy demand, a combination of thermal insulation (like an inflated dome with an insulating layer) and in-floor heating is often considered more practical than relying solely on heat pumps.
Given the scale, the heat pump would likely function as part of a hybrid system, managing the base temperature while, for instance, nuclear or solar-powered radiators handle peak heating/cooling loads
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