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HVAC Frequently Asked Questions

Dor-Mar Heating & Air Conditioning has been serving Newark, Columbus, Zanesville, and Lancaster, Ohio and the surrounding areas since 1962. During that time, we been asked some common questions. Here is a collection of some of the most common questions we get asked from time to time.

If you don’t see an answer here for your burning question, reach out to our customer service specialists by phone or web form and we’ll be happy to respond.

Heating and cooling systems are sized based on their tonnage. One ton is equal to 12,000 BTU/H. Residential systems range in size between one to five tons.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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 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.

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.

Unfortunately, prices for home HVAC equipment can vary quite a great deal, depending on size, efficiency rating, single- or two-stage motor, etc. The only way to accurately gauge the cost to replace your system is to schedule a free in-home evaluation by an HVAC professional. Contact us today to schedule a free visit to evaluate your home’s HVAC system needs.

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.

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.

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.

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

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.

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.

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. Read it here. [link to article]

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See what our satisfied customers have to say:

Brian was great! He called before coming to our house, very courteous, asking if 20 minutes was enough time. Arrived within time stated and took time to acknowledge/ pet our dogs, making them feel comfortable. He then went on to explain what he was doing, walked me thru the process as he went along and even waited to check results of his fix. He suggested a few extra services but was not pushy. Overall pleasant experience!"
Laken Ackroyd
"Robert came to clean our ducts today. He was able to come early & called before he came. He let me know what he was doing during the process & did a great job. He even cleaned the dryer vent! I recommend that anyone call & schedule a duct cleaning. You would never imagine how dusty they are! (Robert even showed me pictures of them!)"
Megan Miller
"Dor Mar came out today and serviced my A/C. Ron was the person who serviced it. He cleaned off all the build up throughout the years and told me every thing he checked was in good shape. when he was done he showed me how to keep my A/C unit clean through out the year. Ron answered all my questions. I was very happy with the service. Thank you Ron/Dor Mar for doing a great Job!!!!"
Bryan Hoops


Newark • 740.345.6639
Columbus • 614.238.6689
Buckeye Lake • 740.817.4058
Dublin • 614-.545.8939
Grove City • 614.595.3098
Pataskala • 740.564.6241
Reynoldsburg • 614.365.1579
Westerville • 614.381.1540
Zanesville • 740.454.2420
Marco Island FL • .239.382.7077
Naples FL • 239.376.1051"
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HVAC customer service in Newark, Ohio | Dor-Mar Heating & Air Conditioning

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