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The idea of heat rising comes from hot air being less dense than cool air (contrary to the convention on internet political forums), and therefore becoming "buoyant". M3 Mitch is pretty obviously correct, in that metals do not expand enough with heat to make upper surfaces significantly warmer than lower ones. Radiant heat goes in the direction of the radiation. If it didn't, the heat in the atmosphere would cook off the atmosphere and leave Florida beach sand cold on sunny days. The idea of "heat wanting to move where it is cold" is another (colorful) way of stating an aspect of entropy. Place a cold bar of steel next to a hot bar of steel, and they will over time come to a common temperature. Convection heating is what TechGromit is referring to, so in a sense, everyone is correct, just not seeing all aspects of the elephant.
Let's just say that our experts were not transported to paradise by the EdenPure we did review. The unit was the second-lowest-scoring space heater we tested, earning only a 24 out on our 100-point scale. According to the folks in our Tech department who tested space heaters, the EdenPure provided lackluster temperature control and was not particularly easy to use, What's more, it was pricey and lacked an overheat-protection feature (key for safety). The GEN3 models do have this important safety feature, according to BioTech Research.
If you're in the market for a new space heater, be dubious about any heater whose manufacturer claims the appliance will slash your heating bills. Here's why:
For every degree that you lower your home thermostat in the winter, you'll save about 3 percent on heating costs. So the only way to really save with a space heater would be to use the unit in the room you're in and turn down the thermostat elsewhere in the house so that your main heating system would not operate. To save 50 percent on your heating bill, you'd have to lower the home thermostat about 17°F. Also, based on national average fuel prices, using an electric space costs more than twice as much to operate as a natural-gas-fueled central-heating system.
Before you shop for a space heater, read our report, which includes buying advice and ratings of electric convection, electric fan-forced, and electric radiant models. We also tested propane and kerosene models but found a safety risk with that type.
The idea of heat rising comes from hot air being less dense than cool air (contrary to the convention on internet political forums), and therefore becoming "buoyant". M3 Mitch is pretty obviously correct, in that metals do not expand enough with heat to make upper surfaces significantly warmer than lower ones. Radiant heat goes in the direction of the radiation. If it didn't, the heat in the atmosphere would cook off the atmosphere and leave Florida beach sand cold on sunny days. The idea of "heat wanting to move where it is cold" is another (colorful) way of stating an aspect of entropy. Place a cold bar of steel next to a hot bar of steel, and they will over time come to a common temperature. Convection heating is what TechGromit is referring to, so in a sense, everyone is correct, just not seeing all aspects of the elephant.
Yes, its is a basic law of physics, the First Law of Thermodynamics.
The transfer of heat is normally from a high temperature object to a lower temperature object.
Conduction is heat transfer by means of molecular agitation within a material without any motion of the material as a whole. If one end of a metal rod is at a higher temperature, then energy will be transferred down the rod toward the colder end because the higher speed particles will collide with the slower ones with a net transfer of energy to the slower ones.
I have a commercial air portable AC unit/heater. AC is 12000BTU's/Heater is 11000BTU's. Cost was 549.00/WalMart.
I live in a well insulated 700sq.ft mobilehome with drywall,new windows, doors, etc and it is a 1967 model. Put in a new electric furnace last year and last winter had 300.00 plus bills.
This year we used 2 ac window units and portable 12000btu unit and lite bill was between 100 and 175. We had about 30 days above 100 degrees.
This winter I turned my electric furnace down to 55 and use my portable 11000btu heater mode and it has a high efficient heat pump in it. We use a fan to blow down hallway and front of trailer stay constant 76 and hallway is 70.
We also use a Dura flame quartz heater in our bedroom and that works good and use fan to blow also in hallway, back bedroom, and bathroom. When all is running our electric meter outside is running slow compared to when electric 10000k furnace is on, meter spins very fast.
We will be getting our light bill in a week so will see how much difference there will be. Temps here have been in 20's at night to 30's,to 60's in day.
To add a ac heat pump to our furnace would cost 3000 plus so that is why we are trying this now.
If you have central air I'd stick with the central air heat. Don't use those cheap polyfiber air filters. Use a low grade pleated air filter. Using this will help to clean the air in the home. Some pleated air filters are almost HEPA quality but could over work your central air unit. You being in Florida, I'd suggest you spend the $100 to $110 for an automatic thermostat. These thermostats will allow you to set an AC temperature and a heat temperature. If it gets cold at night, it'll automatically switch to heat if the temperature drops in the home. You leave for work and it warms up, the AC will switch on and keep the home cool.
If you still insist on using space heaters, you're better off using heaters filled with mineral oil. These are usually the old fashion radiator looking heaters or the long narrow baseboard heater. Which you choose depends on your room layout. My personal favorite is the oil filled radiator heater with digital thermostat. These are very slow acting when trying to warm a cold room. What makes them so good is they don't generate enough surface heat to burn your skin or paper. The slow gradual heat they generate feels more comfortable to me. As the warm air rises from the heater, it draws in the cool air from the floor. It's not enough of a movement that you can feel but it's there. With the digital thermostat, it gives you a greater measure of control. Set it to your favorite temperature and wait a few hours before deciding if you need to raise or lower the thermostat then wait another hour or two. Some like the baseboard type heater because it takes up the least amount of space and can be nearly invisible against the wall. To me these just don't have enough surface area to make them anywhere near as effective as the radiator type heaters. So many people want the fast and nearly instant heat of the cheaper types of heaters. These make my skin get prickly and are also the most dangerous. If you use the radiator heaters, try leaving the ceiling fans off for a few hours. If you do leave the ceiling fan on, make sure it's reversed (blowing air up towards the ceiling).
If you have a thousand or two to spend I'd suggest you consider changing over to a heat pump unit with electric heat strips back up. During the mild winter, the AC compressor will run in reverse to draw heat from outside and then move the refrigerant into the home to give off the heat. When the outside air temperature gets too cold for this process to work well, the compressor will stop and the electric heat strips will turn on. Heat pump systems use less electricity than heat strips units.
For my home, we use our central air with electric heat strips. I'd prefer heat pump or natural gas but we don't have gas available nor can we afford to replace the central air unit with a heat pump.
If you have central air I'd stick with the central air heat. Don't use those cheap polyfiber air filters. Use a low grade pleated air filter. Using this will help to clean the air in the home. Some pleated air filters are almost HEPA quality but could over work your central air unit. You being in Florida, I'd suggest you spend the $100 to $110 for an automatic thermostat. These thermostats will allow you to set an AC temperature and a heat temperature. If it gets cold at night, it'll automatically switch to heat if the temperature drops in the home. You leave for work and it warms up, the AC will switch on and keep the home cool.
If you still insist on using space heaters, you're better off using heaters filled with mineral oil. These are usually the old fashion radiator looking heaters or the long narrow baseboard heater. Which you choose depends on your room layout. My personal favorite is the oil filled radiator heater with digital thermostat. These are very slow acting when trying to warm a cold room. What makes them so good is they don't generate enough surface heat to burn your skin or paper. The slow gradual heat they generate feels more comfortable to me. As the warm air rises from the heater, it draws in the cool air from the floor. It's not enough of a movement that you can feel but it's there. With the digital thermostat, it gives you a greater measure of control. Set it to your favorite temperature and wait a few hours before deciding if you need to raise or lower the thermostat then wait another hour or two. Some like the baseboard type heater because it takes up the least amount of space and can be nearly invisible against the wall. To me these just don't have enough surface area to make them anywhere near as effective as the radiator type heaters. So many people want the fast and nearly instant heat of the cheaper types of heaters. These make my skin get prickly and are also the most dangerous. If you use the radiator heaters, try leaving the ceiling fans off for a few hours. If you do leave the ceiling fan on, make sure it's reversed (blowing air up towards the ceiling).
If you have a thousand or two to spend I'd suggest you consider changing over to a heat pump unit with electric heat strips back up. During the mild winter, the AC compressor will run in reverse to draw heat from outside and then move the refrigerant into the home to give off the heat. When the outside air temperature gets too cold for this process to work well, the compressor will stop and the electric heat strips will turn on. Heat pump systems use less electricity than heat strips units.
For my home, we use our central air with electric heat strips. I'd prefer heat pump or natural gas but we don't have gas available nor can we afford to replace the central air unit with a heat pump.
Unless your system is designed with a filer size for those pleated filter they will make your central unit less effiecent. This is pointed out in mnay forums by experts. Basically it will limit the exchnage of sir rate.Use a good fiverglass filer unless you have specific problems with COPD and the their are better filters and I advise having return larger to aqccomdated them efficently.
Unless your system is designed with a filer size for those pleated filter they will make your central unit less effiecent. This is pointed out in mnay forums by experts. Basically it will limit the exchnage of sir rate.Use a good fiverglass filer unless you have specific problems with COPD and the their are better filters and I advise having return larger to aqccomdated them efficently.
We use the low grade pleated filter for our home. We live out in a country trailer park with a dusty gravel road and have a shedding dog. We tried the poly-fiber filters for three months. Didn't notice a difference in our electric bill but did notice we had to dust almost daily. With the pleated, we dust every week.
Heat doesn't go where it's cold. Heat rises. Ask my basement. Ask my attic. They'll tell you!
Heat doesn't rise, hot air rises. There is a distinct difference. This is a good analogy for your basement if you want to try a simple experiment, place a cookie rack on your counter top. Boil some water and place the pot on the rack. After a minute take the pot off the rack and put your hand on the countertop, it will be warm.
The reason the counter top is warm is because heat is being conducted from the bottom of the pot, into the air and then into the counter top. It's also being radiated from the pot. These are the other two ways heat is transferred to colder objects. This is also why radiative heat in the ceiling works and why your basement will stay warmer than outside.
I'll give you one more example, if you had the perfectly insulated room that no heat could escape from at 50 degrees and started an electric heater most of the heat is going to rise with the air. When you turn that heater off you're going to have a layer of hotter air near the ceiling driven there by convection. As time progresses every molecule of air in that room from the floor to the ceiling is going to equalize in temperature.
Convection is generally the fastest way heat moves but it's not the only way. The conductive and radiative processes also play a part but they are usually slower actions.
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