Tips on how to maintain your air conditioner
Central air conditioners, unlike a majority of furnaces, are complicated mechanical systems. In order for them to work correctly they depend on a number of conditions.
They are sized so that they meet a specific “load” on your home, and have been designed to contain a certain quantity of refrigerant, which is called the “charge.” Air conditioners have also been designed to have a specific air flow amount across the coils. If any of these conditions change, there can be problems with the system.
If more heat is produced indoors due to either changes in the home, appliances or having more people in it, then your air conditioner might be unable to keep up with these changes.
If the system’s refrigerant charge leaks out, the system’s capacity is lowered. What will happen is you’ll get less cooling. When the load becomes high, your system won’t be able to keep up.
If there is a reduction in airflow across the condenser (outdoor) coil, there is a reduced ability for rejecting outdoor heating. The system’s capacity again might go down, especially when outdoor temperatures are higher.
Changing The Filters
Nearly every air conditioning system contains a filter that is upstream of its evaporator coil. It can be in special slots that are part of the duct system or in the return grille, and it can be a folded paper or fuzzy-looking filter. Particles are removed by the filter from the air stream. This removes particles out of the air and keeps your air conditioning system clean.
As the filter continues doing its job, it keeps getting loaded with additional particles. It has the effect of actually making things more efficient, however it also reduces airflow and increases resistance. You need to change your filter when this occurs.
Not changing the filter will result in air flow being reduced and your system not performing as well. Also, if the filter gets too dirty, it will begin to actually become an air pollution source itself.
If you completely take the filter out, it will solve your problem of low air flow. However, it would be a short lived victory. All of the particles that would have been eliminated by the filter will build up on the evaporator coil. This will cause it to eventually fail. It is much less expensive to get a new air filter.
When you purchase a new filter, I would recommend that it be one that has a 6 or higher Minimum Efficiency Rating Value (MERV).
Maintaining Your System
Most consumers can handle changing filters and many routine maintenance procedures. However, some do require professional service.
One thing you should do is brush obstructions and dirt from the drains and coils at the beginning of every cooling season. You may need to have a professional come out for a service call, depending on your skills, time and system.
If your system isn’t producing a normal amount of cold air, it might indicate problems with air flow or refrigerant charge. You will need professional servicing to solve these problems.
Ducts Really Matter
Duct leakage can be another thing causing a system not to produce a sufficient amount of cold air. As much as 20-40 percent of energy can be sapped by duct leakage, even from an air conditioner operating well, if the ducts are passing outside of the cooled area (including garages, crawlspaces and attics). It is important that outside ducts be well insulated. There are different products available for insulating ducts. These can be installed by either a professional contractor or skilled home owner.
Sealing leaky ducts may get you an added half ton of free air conditioner capacity. A handy homeowner can use mastic to seal the ducts if they are accessible. Mastic is a sticky white substance that can be painted onto the ducts. Or a professional can be hired to seal your ducts for you.
Increasing Energy Efficiency
Probably the most important one thing you can do for improving efficiency is sealing leaky ducts. However, many other issues that we have also mentioned will also help: cleaning the coils, maintaining the right airflow and charge and replacing dirty filters.
Another thing you should do is ensure the condenser (outdoor) unit isn’t hidden so that its air flow gets blocked or doesn’t get clogged with leaves and other debris.
If you are considering replacing your air conditioning system, you should purchasing a high efficiency one. Seasonal Energy Efficiency Rating (SEER) is the most well-known efficiency rating. The minimum efficiency you will want to take into consideration is SEER 13, however higher efficiencies are usually very cost effective as well.
Lightening Your Load
One way of making your air conditioner perform better is to reduce the size of job it needs to perform. This can be done by making improvements to the building or lessening the loads that are internally generated that your air conditioner has to contend with.
You can improve the building “envelope” by doing things like reducing air leakage, shading windows or increasing insulation levels. These types of improvements will reduce the amount of energy that is spent on cooling and heating. However, they might require a substantial investment in money or time. Whenever you are having new windows or a new roof installed, using high-efficiency products is almost always cost effective. For example, “cool” roofing” can save as much as one half ton of cooling over one year in addition to lots of energy.
It can be simpler to reduce internal loads. Shut off equipment, lights and electrical appliances that are not needed. Shift your use of appliances (like dryers and washers) to times of the day that are cooler. Local exhaust fans can be used for removing humidity and heat from baths and kitchens. It is also helpful to purchase Energy Star or other appliances with similar efficiency.
Other techniques can be used in some climates for reducing the load placed on an air conditioner. Evaporative air conditioners (a modern version of the “swamp cooler”) can be used in dry climates to provide substantial cooling. In a climate that has big temperature swings, like dry, hot climates, the load can be reduced by bringing in high amounts of cool air from the outdoors. These systems are referred to as residential economizers, ventilative cooling or night cooling.