The problem with explaining how refrigerators and freezers work is that an even barely sufficient explanation requires knowledge of rudimentary thermodynamics. An insufficient explanation might go like this: Electricity drives a motor that pumps a fluid through the refrigeration plumbing. This fluid, which typically is a gas at room temperature and pressure, has the property that when compressed it gets hot, and when expanded, it gets cold. (This is true of all gases per the Ideal Gas Law.) If the cold gas (now a liquid) is put into contact with a warm surface and allowed to expand to its gaseous form, it absorbs a lot of heat from the surface. When this gas is further pumped and compressed, and then subjected to a surface cooler than it is, it gives up its heat and condenses back to a liquid that is warmer than the exterior ambient. However, when later in the loop expended back to a gas, it gets colder than the interior air and can thus cool it. The expansion part occurs in an expander, and the condensation part occurs in a condenser. The condenser in your refrigerator, like the condenser in your car air conditioning, is a radiator that moves heat to the air. The expander in your refrigerator, like the expander in your car air conditioning (usually buried in ducting and less easy to see) is a radiator operating in reverse by absorbing heat from the air passing through it. The efficiency of this heat transfer loop is mainly determined by three processes: the efficiency of the thermodynamic cycle being used by the system, the motor electrical to work efficiency, and losses from friction moving the gas around. The thermodynamic process prohibits attempts to get something from nothing, or even break even (no perpetual motion machines; no free work). In principle, two separate systems, one for the refrigerator and one for the freezer can be sized and optimized for each such that the total power used in some standard environment is not greater than that used from a freezer only single system that controls the rate of cold air moved to a refrigerator. It could with careful tuning be more efficient. Analyzing such systems is fairly complex and specialized, and designing and building prototype optimal ones (for aerospace applications say) can cost millions of dollars. For residential units, some standardization is expected in selection of compressors, condensers, and expanders such that the last erg of energy savings is not going to be met. One expects for residential units that the efficiency will be as noted on the sticker for some environment, and the buyer has to determine whether differences in electricity cost, differences in purchase cost, and differences in other features make the purchase worthwhile. kas

Thanks V, Today Im having another vendor that is actually doing a heat-calc. Finally. My model number is 58MXA10011116, and I digged some specs: IP(MBH), OP(MBH),AFUE(%) 100.0, 93.0, 92.0, It is supposed to deliver a max CFM of 1315. I suppose there are some losses in the duct system -- which has two sizes, corresponding to two different vent outlets. Without actually measuring those metal (alloy, like alum) ducts (I'll get there!)I'd say ducts seem to be have an OD 6" and perhaps 10", I may be off, they have quite a bit of insulation. I got many quotes, right now I can write here numbers of those who send emails. What is disturbing is that many of the vendors said right of the bat that the furnace was too small, and we would need to replace it with a bigger 80% AFUE. Well, Im glad we did not heed those matter-of-fact recommendations.. I wonder how many people fall for those? One guy offered (among other less top-of-the line items) Trane XC95: TUH3C100ACV4VA XL20i A/C : 4TTZ0048A1000A XL20i Heat Pump : 4TWZ0048A1000A. Other did offer to install this: Carrier 80% A.F.U.E Infinity Series Variable speed furnace with 110,000 B.T.U.H Heating Input. Model # 58 CVA110-1--20, Connected to (1) Carrier Puron cased performance series "N" Coil with 4 Tons of Cooling model number CNPVP4821ATA. From The Evaporator Coil an Insulated line set will be connected to (1) One Carrier Infinity Series up to 17 S.E.E.R (4) four tons of cooling condenser with (2) Two stages of cooling. model number 24ANA748A003. Other people just offered to couple our existing furnace with some Carrier condensers that were 4tons, per the model number. Nobody seemed keen on following up on the advanced evaporative coolers, which are very appropriate for this dry climate. Some of this swamp coolers demand a fraction of the electricity, and do not consume the level of water that traditional swamp coolers do - yet, the vendors are pushing the A/Cs in this area hard - i wonder. Thanks for your thoughts, I think this is reassuring. Will post more numbers, etc. mia

What are the benefits of using a Portable Evaporative Cooler? – Super Energy Efficient: Using portable air coolers is very cost-effective to cool your place without spending much money on electricity. Swamp coolers cost up to 50 percent less than air conditioners that use refrigerated cooling systems. Imagine that, a 36-inch swamp cooler working for 8 hours typically costs you less than $1! Because the operating costs needed are only for water and electricity. Even some swamp cooler designs don’t need any electricity. – Zero Emissions Since the system leaves a low level of carbon footprint, it produces no emissions. Unlike other traditional cooling systems, the evaporative cooler has no refrigerant gas or compressor. Furthermore, it releases no toxic chemicals in the air. Swamp cooling systems use no refrigerants that potentially harm the environment. Most refrigerant chemicals used in air conditioning systems deplete the earth’s ozone layer. As a result, they cause global warming to occur. – Prevent of Air Pollution The cooler is fitted with a filter to help filter out odor-causing pollutants and dirt from the indoor atmosphere. Consequently, the quality of indoor air in your rooms will be improved significantly. Apart from being eco-friendly, the cooler additionally safeguards the rooms of your home from air pollution. The Airy Plant is yet another highly innovative product widely used to purify air in an efficient way without energy. – Portable and Practical You can easily drag the cooler to any room. You can also pack the device easily, as it was designed to be moved around effortlessly. – Cost-Effective Setup Unlike the traditional air conditioners, you can set up your portable evaporative cooler in an inexpensive way. These systems are cost-efficient considering there is no need to set aside any amount for installing the device. You can buy the evaporating cooler from the online stores and simply install it in any of your rooms. After a certain period has elapsed, it is recommended that you clean the water tank, the motor, and filter components. Thankfully, you can perform the tasks with no prior expertise or experience. – Adds Moisture The evaporative cooling devices boost the level of moisture inside your home. Therefore, if you live in a region that experiences dryer climatic conditions, the cooler will come in handy. The standardAC systems have a major downside. Unlike the evaporative cooler, the traditional AC units take out moisture from the environment indoors. Note that eliminating moisture from the indoor atmosphere potentially causes breathing difficulties. Furthermore, it is likely to cause cracking or drying of skin. 3. Is there any shortcomings of using Evaporative Air Coolers? – Since Evaporative Cooling Systems increase the level of humidity inside homes, do not use them in areas of humid climates. When compared to the traditional AC systems, Evaporative Coolers cool down your home to higher temperatures. Moreover, they require basic maintenance at least once every month. – Portable air coolers are designed to use water continually. In the locations having limited supply of water, homeowners might be wary of adding the cooler considering their water-use impact. – In areas experiencing low-humidity, evaporating water in the air allows homeowners to enjoy a highly energy-efficient and natural cooling method. Swamp Coolers work using this concept. These coolers cool the exterior air by letting it flow over water soaked pads. This, in turn, causes water in the pads to evaporate in the cooled air. The cooler air which reaches temperatures of between 15 °F – 40 °F is then guided into the house. The warmer air, on the other hand, is pushed outside through the windows.

I grew up in Phoenix and lived in Tucson for about 10 years. In Phoenix you absolutely need regular central air and heat for comfort. Its just too dang hot for a swamp cooler to work. And that's dry heat. Tucson is at a slightly higher elevation and doesn't get quite as hot. I had a window swamp cooler in a tiny house there, but there were days when it just didn't work; either too hot or too humid. It wasn't a huge deal at the time, I was young, I was renting, I worked during the days. But in a retirement home, where you might be spending more time in the home, I would def go for maximum comfort. If you got a heat pump, you would have air and heat without a furnace. You can use a heat pump with ducts or mini-splits. You wouldn't need radiant heat or a wood stove. The heat pump can be installed outside like regular ac with splitters that come through the wall in each room and use wall mounted boxes. In a house like you are designing for ductless, you would probably need three boxes. Another advantage, is that you can turn off the boxes in rooms you are not using so you don't always need to cool or heat the entire house. For example, at night when sleeping, you could just use the box in the bedroom. Once up, you could just use the living area. You wouldn't need to use the box in the second bedroom unless you had guests. I think a heat pump with splitters is more expensive to purchase, but it the long run, it would save on electricity. A heat pump with ducts would be ideal, but you wouldn't be able to turn off the boxes in individual spaces.