Proper equipment sizing is critical. Did you know that is takes at least 15 minutes of run time for an AC unit to reach peak efficiency? Longer run times are good, when oversized a system cycles more, costing more money to start the compressor more often and more wear and tear.
In addition oversizing causes the temperature to bypass the set point of your thermostat creating what I call the rollarcoaster effect. Up and then down, too cold then too warm. Proper sizing will help level that out and with a multi stage or variable speed AC unit will give you comfort like you have never known before.
In an attempt to lower nitrate emissions from gas fired furnaces the State Of Ca required manufactures to come up with new technology to do just that. Unfortunately the outcome has not been good with many "bugs" trying to be worked out even after the release of the units. Roof top units starting this year also had to incorporate this same technology and so far is proving to be difficult. Trane basically released one furnace line and had made necessary updates to have a successful product. However with the States ultimate goal of electricficaiton, and eliminating natural gas, Trane has set there focus on Heat pumps for
CA, which for the climate here is a great option. Most furnaces are oversized due to the mild climate, and tend to overheat the average home, mountains excluded, so heat pumps provide more comfort and less "drying" of the air as with a natural gas unit.
First of all this clarify Freon. Freon is actually a Brand name. The most common types of refrigerant are R22 and now R410. If you are low on refrigerant then you have a leak in your system somewhere and it needs to be located and repaired. In most cases the evaporative coil has a leak, or possibly a damaged outdoor unit (condenser) etc. If you chose to continually add refrigerant, then you are heading to compressor failure, higher electric bills and reduced performace.
In 2014 I took a class offered by SCE that taught contractors to learn how to perform computerized load calcuations and Manual D duct design. SCE had found that most sytems in Southern Ca were oversized and under ducted.
Proper sizing, both for equipment and ducting is critical for proper performace, efficiency and comfort. We use the Wrightsoft Program for both tasks. If you are considering a contractor that doesnt utilize this technology then I would suggest you move on to someone who does.
Well no, undersized ducting causes increased velocity due to the increase in static or restriction. In addition an inadequate register size or style such as a stamped face register, will also increase the speed of airflow and make it loud. Properly sized ducting for both return and supply will result in more quiet air delivery, reduced noise at the return air, or intake, and better efficiency while still delivery the requried volume of airflow.
Most air returns, or intake air, whether it is the actual duct size or the filter itself are simply too small. This causes increased static or resistance which makes your blower motor work harder and your system less effificient. Your unit can only push out what it can pull in. The bottom line is most filter are undersized and when you chose a high rated filter it makes your system work harder. The manufactures also will claim that it is a 90 day filter. This isn't necessarily true since the more efficient the filter is the faster it gets dirty. You can look into increasing your return air grill or adding a media filter cabinet with a large capacity filter that will help your system breathe easier, increase efficiency, and improve indoor air quality.
In an attempt to reduce global warming the refrigerant manufactures are developing new refrigerants. The lastest one that could become the standard actually will use a flammible gas such as propane. Do I need to say anymore? Really? Does anyone really want a flammible gas running through lines in their home and eventually when the system gets a leak then what?
You cannot compare this to natural gas used in you home since it runs through piping that will outlast the house itself in most cases.