Dor-Mar Dublin Heating and Air Service

There are a number of factors to consider when you are facing a large repair bill. Should you fix the existing system or replace with a new one? This is such an important question that we’ve written an article covering all the factors.

One of the most important functions of an HVAC professional is to accurately size a replacement system for your home, based on a heat load calculation. This is nearly impossible without an on-site visit to take measurements, and to survey the home, its current system and ductwork. In an HVAC system, bigger is definitely not always better. Accurate sizing is most important.

During cold weather months, frost can accumulate on the outdoor coil, causing the heat pump to run a defrost cycle for one to ten minutes. Your system will return to heating mode once the ice is gone.

A heat pump produces air around 80°, still considered warm; but 80° may feel cool to your hand, which usually hovers around 90°.

During the heating season, cool outdoor air enters your home and tends to dry out as it warms up. That increases static electricity and can cause dry sinus problems. Adding a humidifier adds moisture back into the air, reducing sinus issues. Humidifiers generally have little effect in the cooling season, as humidity hovers around a low 40 percent.

This is a definitely NOT something we recommend. Closing registers decreases airflow and efficiency; by closing registers and doors, you’re disrupting airflow and you’ll cause your system to work harder to distribute air to other areas of the home. That causes the system to work harder, cycling more and running with less efficiency.

If your air older conditioner uses “Freon” or R22 refrigerant, your home is being cooled with an outdated, environmentally hazardous refrigerant. Because R22 was found to cause damage to the Earth’s ozone layer, Congress passed a law in 2010 requiring the eventual phasing out of R22 by the year 2020. R22 production has been limited for the past several years, so if your system springs a refrigerant leak, the cost of refilling the relatively rare R22 could make the repair more expensive than it’s worth. And, you can’t simply replace R22 with its replacement refrigerant because system parts aren’t compatible. This means the next time your aging air conditioner requires a repair – especially a refrigerant-related one – it’s probably time to upgrade to a unit that runs on “Puron” also known as R410A. While this requires an investment, the resulting increased efficiency, better air quality, increased comfort and improved reliability are worth it.

Check to ensure the air handler or furnace is plugged in and receiving electricity – check that the breakers and disconnects are turned on and the thermostat is set correctly. If you are calling for AC service during the cooling season, we ask that you turn off your system at least 3 hours prior to our visit. If you coil is iced up, we cannot work on a system until it thaws.

We recommend a maintenance plan that includes twice-yearly checks on the system, one in the fall and another in the spring. That allows our service technicians to catch any potential issues before they happen, saving you higher repair costs. Our maintenance programs are designed to keep your AC and heating systems running at peak efficiency all year long.

A short checklist of tasks every homeowner should do on their AC system: - Change filters regularly - Clear debris, clutter, weeds, or other landscaping from your outdoor unit, it may restrict airflow - Keep your family pets away from an outdoor unit; urine can cause extensive, expensive damage - Use extra caution using a string weedeater around your outdoor unit to avoid damaging wiring or cooling fins. Anything beyond this, we recommend you hire qualified, certified HVAC technicians, like the team at Dor-Mar Heating & Air Conditioning.

We recommend you replace your home’s disposable filters at least once monthly. If you use washable filters, you should wash them once a month. This gives you optimum efficiency and filtration.

There are a wide variety of electronic programmable thermostats available today, which are much more efficient and accurate than old-style thermostats that use mercury switches. Using a programmable thermostat, you can regulate your home’s temperature by time of day, depending on whether it’s occupied or not. When everything is automatic, you never have to remember to change the setting. Also, many newer thermostats connect to your home’s WiFi, allowing you to manage your home’s temperature remotely with an app on your smartphone or one of the smart devices gaining popularity (like Amazon Alexa, Google Assistant or Apple Home). Programmable “smart” thermostats are definitely the way to go these days. We highly recommend a programmable WiFi thermostat.

In the summertime, average popular temperature settings hover around 78° to 80°; in colder months, 70° to 72° seems to be the most comfortable setting in our area. If you have a programmable thermostat, you can save energy by raising and lowering the temperature depending on whether your home is occupied, but you shouldn’t change the temperature by more than 5° when you come and go; doing so will make the HVAC equipment work harder to set the temperature back to normal later.

Your air conditioner system’s air temperature depends entirely on the temperature of the air entering the system. Generally speaking, air temperature produced by an AC unit should be 18° to 20° lower than the air that enters the system. For example, if air entering the system is 80°, air coming out should be around 60° to 62°. That is accurate on a system that’s been running a minimum of 15 minutes on a warm, dry day with an air temperature around 80°. On a day with milder temperatures, with the indoor temperature in the low 70’s, or when humidity is much higher, air exiting the unit may only be 15° to 17° cooler than what is entering.

Air conditioners use a lot of energy and do not produce a lot of cooling when they are first starting up. A system that is undersized is less expensive to run, but of course delivers less comfort for the home’s inhabitants. Although it runs non-stop, it will probably use less energy than a larger system that tends to cycle on and off. Usually, a unit that is either running or off costs less to operate than a unit that cycles on and off.

Not necessarily. A larger system with higher capacity costs more energy to operate, and may have to work harder. A system with too much available capacity will run in short cycles, turning the system off and on repeatedly, causing it to be less efficient. In addition, air conditioners only remove humidity while it is running – shorter run cycles don’t remove humidity from the air as well as it should.

Unfortunately, there is no exact answer. Air conditioners are sized to remove heat from a home as quickly as it enters, based on a 110° day. On a 110° day, a system should be able to keep up with incoming heat, but not make gains and turn itself off. The further below 110°, the more the system will cycle on and off.

First, and most importantly, you should clean and replace your HVAC filters frequently. Allowing your system to breathe more freely requires less work on the part of the blower motors. Windows that are exposed to excessive sunlight benefit from shades, drapes or tints and cause the system to work less. A system heats or cools more evenly when the blower is “on” and keeps the air moving constantly throughout the home, and constantly filtered.

The amount of cooling an AC system will deliver per dollar spent on electricity uses the Seasonal Energy Efficiency Ratio (S.E.E.R.) rating system, defined by the Air Conditioning, Heating and Refrigeration Institute in its 2008 standard AHRI 210/240. The higher a cooling unit’s S.E.E.R. rating, the more energy-efficient that piece of equipment. In the USA, the SEER is the ratio of cooling in British thermal unit (BTU) to the energy consumed in watt-hours. S.E.E.R. ratings can range from 13 to 17.

There is no one size that’s right for every house. One ton of AC can cool anywhere between 300 to 800 sq ft, depending on how your home is constructed, affected by the construction of your home. The best way to ensure the system installed in your home is properly optimized (not too small or too large, but just right) is to have your home assessed by a certified HVAC professional.