There is a lot of confusion about why New Jersey home inspectors cannot test an air conditioning unit in cold weather. Often clients do not understand why this is the case. it important for home inspectors in NJ to inform their clients before the inspection that this is likely to be the case when doing home inspection in the winter months.
It is tempting for a NJ home inspector to operate the a/c unit in cold weather in order to provide the information the client needs to make good decisions about the home that they are buying however it is not a smart idea.
Residential air conditioning units cool the air by changing the pressure of refrigerant and also the state of the refrigerant in the system. While operating the air conditioner changes the state of the refrigerant from a gas to a liquid and then reverses this process. As the refrigerant is moved across the air conditioner coils heat inside the home is absorbed by the refrigerant in the coils. The heated air then is delivered to the exterior of the home through the exterior compressor fan unit. The colder air is also distributed to the interior. Heat is then delivered to the exterior. During this process the liquid refrigerant is turned back into a liquid and the process cycles on.
The refrigeration process works efficiently when temperatures are mild. Air conditioning units in homes are not designed to operate under 60 degrees. 60 Degrees is typically below the interior temperature comfort level of most people. Operating the air conditioner when it is below 60 degrees can result in a failure of the compressor unit.
Air conditioning refrigerant is designed to switch from a liquid to a gas in the air conditioning system. If the refrigerant does not change states at the proper times damage can occur. Operating the air conditioner in cold weather can cause the refrigerant not to change to a gas and remain in liquid form throughout the cycle. The compressor unit (exterior unit) is designed to handle the refrigerant when it is a gas but not as a liquid. As a result, the compressor unit can fail.
There are two main parts of a residential air conditioning system. The compressor which is installed on the exterior of the home and an indoor coil unit. The job of the exterior compressor is to distribute heat to the exterior of the home. This is why when you are close to the exterior unit the unit blows hot air to the exterior. The indoor unit allows the refrigerant to absorb the indoor heat which is pumps outside by the compressor unit.
Home buyers should speak to their real estate attorney and real estate agent about what if anything can be done about not being able to test the air conditioning unit. One thing that you may be able to do is hold some funds in escrow until the unit can be tested in the spring months. Most sellers however are likely not to agree with this. You may be able to get the unit warrantied, this is a viable option if the seller is willing to purchase a warranty on the unit and other equipment in the home for you. Just make sure you read the paperwork fully to understand what is and what is not covered. You can also acquire a signed official statement from the seller that indicates that the unit was is in satisfactory operating condition. In any event some protections should be provided if an air conditioning unit cannot be tested in the cold weather months.
There is often a lot of confusion and also frustration about not being able to test central air conditioners in the cold weather months. It is up to New Jersey home inspectors to provide prior notice to their clients when they send out their pre-inspection agreement to avoid surprises. Home inspectors and real estate agents should explain to their clients why the central a/c units cannot be tested in the winter to avoid confusion and frustration.
John Martino
LookSmart Home Inspections
NJ Home Inspectors Lic # 24GI00058700
Board Certified Master Home Inspector
American Society of Home Inspectors (ACI) #244472
International Association of Certified Home Inspectors (CPI) # 200090933
NJ Radon Lic# MET 11963
Commercial Pesticide Lic. (Termite Inspection License) # 27811B
Certified Mold Inspector
5 Preston Ave
East Hanover, NJ 07936
973 407-9621