Reply:
It is never a good practice to mix and match indoor units with another brand of outdoor unit. The engineering that goes into making the air conditioning work to it’s maximum ability cannot be matched by another brand.
I am surprised that this situation has occurred as it is definitely not the right thing to do.
I can only assume that to change the indoor unit would have been a nightmare and they opted for the next best thing.
I am not surprised you are having capacity problems during high heat load conditions with this setup.
I would contact the warranty company and make some serious inquiries.
Yes it would definitely be better to replace the indoor with a matching unit but only after you request that a heat load analysis for your home be carried out (by experienced and technically competent company – not joe joe’s backyard cleaning service, if you know what I mean). Just to make sure the machine can do the job adequately in the first place. Believe me all this will save you money in the long run.
Good Luck

Reply:
You are correct in suspecting the operation of your air conditioner is being hindered by the restriction imposed by the covering. No air conditioner should be covered in such a way as to restrict the airflow.
You will find that by removing the cover that your unit will operate more efficiently during higher ambient temperatures, which is when you want it to.
Aesthetics is the only reason someone would do this to an air conditioner with little or no thought to the machines ability to perform it’s function.
As for the burnt wiring, The sheathing on the wire can sustain much higher temperatures than that caused by the enclosed A/C unit. It is unlikely that the box covering has caused the problem. Burnt wiring is usually the result of a ‘hot’ connection where the connection point of the wire is loose.

Reply:
If you try to do the job yourself you will eventually have to get someone who knows what they are doing to finish off anyway.
It is usual for an installation to stop before completion, if you ran out of money and that is why you are considering doing it yourself you had better wait until the funds are available.
As previously mentioned, if you attempt to do it yourself there is a high likelihood you will either do some damage to the system or it will not work anywhere near it’s capability.
Finally, if you do not install it correctly you will invalidate any manufacturers warranty for the machine. It has to be installed by a qualified and licensed installer.

Reply:
Either your indoor fan motor has burnt out or the relay serving the fan motor is faulty. Either of these requires an A/C technician.
If your ductwork has blown off the indoor unit ( which can happen ) then you need to check in your ceiling space fro this possibility. If you have a zoned system, one of the damper motors could be stuck in the closed position.
My guess is that the fan motor has burnt out as this is usually the problem from what you describe here.
Good luck finding a competent A/C mechanic this time of year ( mid summer ).
Note: if you are having to set your t/stat at 55 and 65 respectively you have machines that are either too small (capacity wise) for your home or there could be a refrigerant leak which causes the machine to be ineffective. They are probably running flat out trying to reach set point, causing your electricity bill to be needlessly high….just a thought.

Visit the EnergyStar site (www.energystar.gov) to find out how to pick the right system for your home. Talk to several different professional installers to get information and estimates. Today places like Home Depot and Sears install heating and air conditioning systems. Talk with family and friends who may have had systems recently installed.
To learn more about Home Heating & Air Conditioning please visit http://www.easy-hvac.com
Article Source: http://EzineArticles.com/?expert=Catherine_Olivia

Today most homes have what is called a split-system. The evaporator coil is inside and the cooling system, which contains the condenser and compressor is outside. They are connected by refrigerant lines running between them.

If you have an older home and are considering making an upgrade to your present air conditioning and heating system you will probably notice a savings of up to 40% if you’re replacing a unit that is 10 years old. You may actually find if you have an older system that you don’t necessarily need the newest top of the line model to get better cooling and heating. Today’s systems are so superior to older ones you’ll notice a difference even if you buy a newer lower end system. One thing you’ll notice immediately is that the compressor is much quieter. You’ll also notice the air coming out of the ductwork is much cooler.

Heat pumps work by pulling “warm” air from the outside, warming it and circulating it through the house via use of ducts. Electric baseboard heating is easy to install, but can be very costly to run, especially with the price of electric today. Electric heating doesn’t use ductwork like a furnace or heat pump. You can keep each room at a specific temperature as baseboards have individual control.

Gas and oil furnaces have been around a long time. A furnace draws air through duct systems in the home where it is heated in the furnace and returned back to the home through the duct system.