Buyers avoid homes with air conditioning issues forcing sellers to deeply discount these homes. Additionally, most lenders require the Air Conditioning works.

We see this first hand in the marketplace. One such experience comes to mind. There was a shortage of homes in the summer of 2013. I was helping a single mother who wanted her son in the top school district. The district has the highest property values.

We were offering on homes and getting outbid. Then I told her we would stand a better chance of purchasing a vandalised or neglected home. A few days later we found a home with a stolen condenser unit. This is quite common. Thieves steal them from vacant homes to sell the valuable metals.  There was no competition to purchase the home. It was also priced far below market value for the area.

We asked the seller replace the stolen condenser unit. They agreed and turned a claim into their homeowners insurance. Then we moved forward and closed out the transaction. The appraisal came in $7,000 OVER the price she paid to purchase the home! Best news is she found a fantastic home in the highly coveted school district.

The market was in the seller’s favor yet they lost $7,000 in lost equity. Their homeowner’s insurance made the repair for a $500 deductible. Worst case, a new condenser unit is $2,000 installed. Ask yourself, “Is it worth spending $2,000 to make $7,000?”

Be sceptical of HVAC contractors

Heating Air Conditioning and Ventilation systems (HVAC) is one of the most feared parts of a home. People readily spend thousands of dollars when only a few bucks could have solved the problem. Most people fail to understand that older HVAC units last longer than new ones. Let me explain below.

I obtained my masters in engineering. I went onto design aircraft systems for military and passenger aircraft. Routine maintenance is the key in maintaining these complex systems as with anything. We also found that complex systems fail most when they are new as the parts are still meshing together. New HVAC units also tend to fail when they are newer. This is the reason for your warranty.

Unfortunately, engineers are getting better at designing failure into HVAC systems so the consumer is forced to purchase again and keep company profits up. Older units last longer than these new ones as a result of intended failure baked into the design. Even so new as well as old air conditioning units last far longer than salesmen, technicians, and manufacturers would lend you to believe. Especially when the units are properly maintained (will explain how later on).

Additionally, manufacturers claim newer units have higher efficiency. These claims are false. There is little if any room for design improvement in cooling systems. Performance is defined by chemistry that has been understood for hundreds of years. Any improvement would be in the compressor or larger heat exhangers (evaporator and condenser coils). Energy savings from a newer compressor would be minuscule and never warrant upgrading a working system. Conversely I see the builders installing smaller heat exchangers. These force the fans to work harder and the system will burn out sooner. You should always lean towards a bit larger system as apposed to smaller. So your HVAC system is not overworked.

AVOID HVAC MAINTENANCE CONTRACTS: These contracts run you hundreds of dollars for a few minutes of work. This work you can easily do on your own. The maintenance contracts do not include replacement cost either. You are better of purchasing a home warranty that covers replacement. Additionally, you can easily go without issue for years, even decades, with only changing your air filters. Some of the really old heat pumps required changing oil in the compressor but those are so old I’ve yet to find one.

AVOID FREE INSPECTIONS: HVAC professionals are in high demand. Figure a good HVAC company will cost roughly $100 for a health check. We find free inspections typically result in equipment you DO NOT need so the contractor can cover the cost of their visit.

UPGRADE FROM EVAPORATION COOLING: we STRONGLY encourage you upgrade if you have an evaporation cooler. Heat pumps cool better and fetch more money than with evaporation cooling. How much more money? We frequently see homes with heat pumps selling for $10,000 more than their evaporation cooling neighbors. System cost is around $5,000 depending on your home and easily recouped in additional equity (given your home is worth more than you owe on it).

Inside the HVAC Unit

You know that cold feeling when you step out of the shower? That is due to evaporation. The water is evaporating, changing to a gas, and in the process absorbing heat. This heat is taken from your body and released into the air. It results in a cooling effect. There are two common coolers based off this evaporation effect.

Evaporation / Free Cooling These coolers are very simple. They have water in them. The water is pumped over fine mesh cooling pads. Much like the scrubber pads you use to wash dishes. Then a blower takes hot air from the house and pushes it through the wet pads. Some of the water absorbs the heat and evaporates. Some of the water is also pumped into your house as a vapor. These systems rely on relative humidity as such. If it is humid outside then the air cannot absorb much more water and your house remains hot.

Heat Pump uses the same process but solves the issues with “free cooling”. Heat pumps use the evaporation effect but do it inside plumbing referred to as a refrigeration cycle.

Part 1 referred to as an evaporation coil is where the fluid changes to a gas and absorbs heat. A fan blows hot air from inside your house across the evaporator. The refrigerant inside absorbs heat as it changes from a liquid to a gas making it cool to the touch. The air blowing across it comes out the vents in your home.

Part 2 is the coil outside the house. This coil has the refrigerant in a gas form and is hot to the touch. The fan there cools down the coil and extracts the heat outside the house. After that coil is a compressor which pressurizes the gas back into a liquid. Then the cycle can repeat itself until your home reaches the desired temperature.

Right before the evaporator coil, in the pipe is a needle valve called the expansion valve. This valve brings the pipe down to a fine point so the compressor can pressurize the gas back to a liquid. The pin point opening in the valve also sprays the fluid out in a mist helping facilitate the change to a gas again.

There are two side effects of the Heat Pump (1) They have the opposite effect and dry the air. (2) They also use a lot more electricity, since your running an extra fan and compressor.

This is a pretty amazing system when you think about it. It basically takes the first “Free Cooling” system and puts the mess inside of plumbing. The compressor lets you continue continue the process until your desired temperature is reached. Then the system turns off.

Maintenance your cooler

Change your filters: They are located where the HVAC pulls air into it to evaporator (aka air exchanger unit), otherwise referred to as the air return.

Balance your vents: so many people complain of their upstairs being hot and down stairs being cold. This is due to an imbalance in the vents. You have to open and close the vents such that the ducts all equally pressurize. You can do this by closing down all the vents except the one farthest the air handler. Then open the next closest a little less and on down the line until you get to the one closest the air handler. Open that one less.

Change your Thermostat Batteries: some thermostats run on batteries. You will want to check those and change them.

Turn your HVAC breakers off, pull any disconnects, turn the gas valves off before doing any of the following. Then double check is safe:

Inspect gas furnace: remove service panel. Blow out with compressed air. Look for signs of carbon buildup around combustion chamber. Look for damage or blockage to combustion chamber vent. Vent should be metal, go straight up and out the ceiling above it. There may also be a metal flange where it goes through the roof / drywall above.

Heat Pump / Condenser unit: make sure the condenser unit (outside) is free of debris. Turn the breaker HVAC breakers off. Then pull the service disconnect out (next to compressor to shut it off) blow it out with compressed air and or spray it clean with garden hose. You can use a high concentration of dish soap to help soak the coil as well, then rinse off. Let it dry then replace the service disconnect, and turn the breaker back on.

Heat Pump / Evaporator coil: Turn off all your HVAC breakers. Locate your air handler (typically in garage, a utility closet, or attic). This contains the evaporator coil (many times the furnace too). Remove the service panel. Locate the evaporator coil and blow it clean with a can of compressed air.

Greasing Blower Fan (pending easy access): Turn off breaker to Furnace. Pending easy access, locate the blower fan (referred to as a squirrel cage). Place a dab of oil on the shaft the cage spins on. Evaporator coils have a belt that spins the fan. You need to test tension on the belt and replace it if it is stretched out.

Evaporation cooling: requires you change out the pads every so often. You may also have to put an additive into the pump system to remove odor buildup. Consider replacing the float valve periodically regardless of condition. Water is poured down the drain when these fail.

Evaporation cooling condenser unit pad: your condenser unit sits on a pad. It is critical this pad is level. Sometimes the ground washes out under them. Then the unit starts to lean. This puts uneven pressure on the fan bearings in the unit and burns the fan out. Make sure your condenser unit is level.

Testing a Heat Pump

These systems are quite simple. They work on basic chemistry and have few parts to them. Think of it this way. Your car has thousands of parts. A well maintained car can run worry free for many years with routine maintenance. HVAC systems have only a couple dozen parts at most. They can easily run for decades.

They only really need to build pressure in the plumbing. The fans need to spin too. Many people think they should immediately hook a set of pressure gauges up to test the system. This is a VERY bad idea. Those diagnostic ports can wear out. You should never hook gauges up unless absolutely necessary.

Instead, check the differential temperature.

1. Turn on the Air Conditioner.
2. Locate the air return. This is typically where your filter is.
3. Measure the temperature of that air return.
4. Next locate the vent closets the air handler.
5. Take the temperature inside the duct as system is cooling.
6. Subtract the air return temperature from the vent temperature.

Modern refrigerants should provide you a difference of 20 degrees Fahrenheit. Ensure maintenance is complete then have licensed technician check pressures if the differential temperature is far below 15F.

Flickering lights and or compressor won’t turn on:

Capacitors are a common issue on Heat Pumps. There is a large capacitor on the power line to the compressor. Think of this as a bucket of electricity. This bucket dumps into the compressor to energize it. Otherwise the large load from the compressor drains your house of electricity when it starts up. It appears as a “brown out”. This can be hard on your other appliances in the house. It can eventually result in the compressor not turning on at all. These capacitors are behind a service panel on your condenser unit. They are very inexpensive, however, consider having a licensed professional replace as playing with high voltage can be quite dangerous.

Before you sell your home

Buyers are easily frightened by HVAC issues. You want to ensure your system is in top notch working condition when a buyer inspects your home.

Fully maintenance your HVAC system. Then check the differential temperature. If it’s less than 20F then you’ll want to have the unit serviced by an HVAC professional.

You may like to have the unit serviced by a professional reguardless. Then you can present the buyer with the maintenance slip. This tends to put a lot of buyers at ease.

Additionally, get a home warranty that covers HVAC and transfers to the new owner / buyer.

Sometimes your agent can get you complementary coverage for your listing period so call them before you order the warranty.