Our local and family owned and operated company at Farnen & Dermer has been a trusted name in HVAC for over 100 years. We offer expert heating, cooling, indoor air quality, and plumbing services to residential properties in Owings Mills and throughout Baltimore County. Our experienced, licensed, and factory-trained technicians will be there in a flash—proudly offering same-day appointments and 24/7 emergency repairs when you reach out to us by phone. If you need heater or AC replacement, we offer free estimates and flexible financing options, so a high-quality system doesn’t break the bank. From speedy AC repairs and heating maintenance to air filtration installation and boiler replacement, our team has you covered—backing up all our services with a 100% satisfaction guarantee.
"THIS COMPANY IS SCAMMING PEOPLE!!! -On 6/24/21, Farnen and Dermer installed a brand new YORK HVAC system in my home. Everything appeared to be fine, and there were no issues for 2 years. -On 8/28/23, I noticed an extremely loud buzzing coming from my outside unit, so I called them to come check on the problem. My unit was still cooling, but extremely loud. Glen A. showed up to diagnose the problem and seemed like a nice enough guy. After about an hour, he informed me that my entire indoor and outdoor unit need full replacement for a total of $10,900. (I paid $7,500 just 2 years earlier). I said, surely this was covered under warranty because the unit was only 2 years old? He then informed me that it was not because it was â struck by lightning and the warranty does not cover an act of god. -At this point in my head things were not adding up, especially since the unit was still cooling, both of my neighbors units were fine (townhouse) and he did not even check the inside unit. I told Glen I need to think about the replacement because that is a lot of money that I do not have at the time. Glen disconnected my outside unit completely before he left with the hottest week of the summer upcoming (95F-98F) and charged me $189 for the visit. -I am lucky enough to have a Fire Marshall as a good friend to ask him about the situation. This guy sees lightning strikes pretty frequently. He told me there is no way that my unit was struck by lightning based off of what I was seeing and also because it would have gotten to all of my neighbors units (townhouse). He informed me it is literally impossible. THE UNIT WAS STILL COOLING! -I decided to get a 2nd opinion from another company. The other company came out and told me that my compressor was bad and that there was no lightning strike to speak of. They also informed me that it was covered under the warranty and they could fix it. The technician said that he noticed the wiring on the outside unit was incorrect. There was a red wire crossed with a black wire. He said that is exactly why my 2 year old compressor went out. This company even put their findings in writing for me. They replaced my parts and got me up and running for 82% LESS THAN F and D! -I am not the only person this has happened to. It appears to be standard practice. You can see the attached pictures of reviews from other people in the same boat on the Better Business Bureau website. I will be submitting a complaint through BBB and demanding a full refund. This is pure predatory behavior and it is unacceptable!"
Dan W on September 2023
Our local and family owned and operated company at Farnen & Dermer has been a trusted name in HVAC for over 100 years. We offer expert heating, cooling, indoor air quality, and plumbing services to residential properties in Owings Mills and throughout Baltimore County. Our experienced, licensed, and factory-trained technicians will be there in a flash—proudly offering same-day appointments and 24/7 emergency repairs when you reach out to us by phone. If you need heater or AC replacement, we offer free estimates and flexible financing options, so a high-quality system doesn’t break the bank. From speedy AC repairs and heating maintenance to air filtration installation and boiler replacement, our team has you covered—backing up all our services with a 100% satisfaction guarantee.
"THIS COMPANY IS SCAMMING PEOPLE!!! -On 6/24/21, Farnen and Dermer installed a brand new YORK HVAC system in my home. Everything appeared to be fine, and there were no issues for 2 years. -On 8/28/23, I noticed an extremely loud buzzing coming from my outside unit, so I called them to come check on the problem. My unit was still cooling, but extremely loud. Glen A. showed up to diagnose the problem and seemed like a nice enough guy. After about an hour, he informed me that my entire indoor and outdoor unit need full replacement for a total of $10,900. (I paid $7,500 just 2 years earlier). I said, surely this was covered under warranty because the unit was only 2 years old? He then informed me that it was not because it was â struck by lightning and the warranty does not cover an act of god. -At this point in my head things were not adding up, especially since the unit was still cooling, both of my neighbors units were fine (townhouse) and he did not even check the inside unit. I told Glen I need to think about the replacement because that is a lot of money that I do not have at the time. Glen disconnected my outside unit completely before he left with the hottest week of the summer upcoming (95F-98F) and charged me $189 for the visit. -I am lucky enough to have a Fire Marshall as a good friend to ask him about the situation. This guy sees lightning strikes pretty frequently. He told me there is no way that my unit was struck by lightning based off of what I was seeing and also because it would have gotten to all of my neighbors units (townhouse). He informed me it is literally impossible. THE UNIT WAS STILL COOLING! -I decided to get a 2nd opinion from another company. The other company came out and told me that my compressor was bad and that there was no lightning strike to speak of. They also informed me that it was covered under the warranty and they could fix it. The technician said that he noticed the wiring on the outside unit was incorrect. There was a red wire crossed with a black wire. He said that is exactly why my 2 year old compressor went out. This company even put their findings in writing for me. They replaced my parts and got me up and running for 82% LESS THAN F and D! -I am not the only person this has happened to. It appears to be standard practice. You can see the attached pictures of reviews from other people in the same boat on the Better Business Bureau website. I will be submitting a complaint through BBB and demanding a full refund. This is pure predatory behavior and it is unacceptable!"
Dan W on September 2023
It is our mission, to provide excellent workmanship and complete customer satisfaction, from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety and quality, regardless of how large or small the job.
"They took the time to diagnose the issue and then clearly explained what was going on."
Richard I on January 2025
It is our mission, to provide excellent workmanship and complete customer satisfaction, from start to completion of a project. In order to understand the needs and expectations of our customers, we take great care to work and communicate with every customer in a professional manner. Our reputation is based on service, safety and quality, regardless of how large or small the job.
"They took the time to diagnose the issue and then clearly explained what was going on."
Richard I on January 2025
Carroll Mechanical is an HVAC contractor that is dedicated to providing clients with the very best maintenance, repair, and installation services. We are based in Eldersburg and service customers throughout the MD region. We are a local business that is built on integrity, transparent pricing, and technical excellence. Our team of expert technicians have experience working with all major manufacturers. Our mission is to keep you comfortable and we proudly offer emergency availability where possible. If you are a homeowner, property manager, or business owner, give us a call today to learn more!
"The project (HVAC replacement) was completed on time and on budget. I particularly appreciated the time and patience provided in answering my questions related to the quote and options."
Linda M on April 2025
Carroll Mechanical is an HVAC contractor that is dedicated to providing clients with the very best maintenance, repair, and installation services. We are based in Eldersburg and service customers throughout the MD region. We are a local business that is built on integrity, transparent pricing, and technical excellence. Our team of expert technicians have experience working with all major manufacturers. Our mission is to keep you comfortable and we proudly offer emergency availability where possible. If you are a homeowner, property manager, or business owner, give us a call today to learn more!
"The project (HVAC replacement) was completed on time and on budget. I particularly appreciated the time and patience provided in answering my questions related to the quote and options."
Linda M on April 2025
We take great pride in our experience, expertise, quality, and customer service that we provide to meet the consumers' needs. It is our mission to provide excellent workmanship, and complete customer satisfaction from start to completion of a project. In order to understand the needs, and expectations of our customers, we take great care to work, and communicate with every customer in a professional manner. Our reputation is based on service, safety, and quality, regardless of how large or small the job.
"Dean and his employees where very professional. The job was well done and very efficient. The price was very good! I would recommend Dean and his employees to everyone. Keep up the good work gentlemen. "
Raymond V on April 2025
We take great pride in our experience, expertise, quality, and customer service that we provide to meet the consumers' needs. It is our mission to provide excellent workmanship, and complete customer satisfaction from start to completion of a project. In order to understand the needs, and expectations of our customers, we take great care to work, and communicate with every customer in a professional manner. Our reputation is based on service, safety, and quality, regardless of how large or small the job.
"Dean and his employees where very professional. The job was well done and very efficient. The price was very good! I would recommend Dean and his employees to everyone. Keep up the good work gentlemen. "
Raymond V on April 2025
We are full-service heating and air conditioning company that provides residential and light commercial service, installation and maintenance. We truly believe that if we focus on helping people and treat others with respect, our customers experience shall be an amazing one.
"poor customer service. service manager insulted me, called me derogatory names while defaming my character. when all I was looking for was for someone to right a wrong. I was actually looking forward to them coming to look at my furnace and was hoping to find a trusted company but was given the complete opposite of what I expected. first no one called me with an update, I had to call, then no one showed by 5pm after I waited patiently all day during their 8-5 window. finally at 5:10 i reached out again only to be met with an after hours line that couldn't help me at all. once I spoke to SM, he insulted me, called me derogatory names and defamed my character all because I was understandably upset for being "brushed off" by everyone I had come into contact the entire day and given excuse after excuse with no solution that was going to benefit me. Customer service and professionalism are lacking 100%"
Tracey S on December 2023
We are full-service heating and air conditioning company that provides residential and light commercial service, installation and maintenance. We truly believe that if we focus on helping people and treat others with respect, our customers experience shall be an amazing one.
"poor customer service. service manager insulted me, called me derogatory names while defaming my character. when all I was looking for was for someone to right a wrong. I was actually looking forward to them coming to look at my furnace and was hoping to find a trusted company but was given the complete opposite of what I expected. first no one called me with an update, I had to call, then no one showed by 5pm after I waited patiently all day during their 8-5 window. finally at 5:10 i reached out again only to be met with an after hours line that couldn't help me at all. once I spoke to SM, he insulted me, called me derogatory names and defamed my character all because I was understandably upset for being "brushed off" by everyone I had come into contact the entire day and given excuse after excuse with no solution that was going to benefit me. Customer service and professionalism are lacking 100%"
Tracey S on December 2023
We invite you to experience a tradition of customer satisfaction that will exceed your greatest expectations. Our professionalism and quality workmanship will accurately reflect your taste and lifestyle. From conception to completion, we work with you until the job is done. We are ethical, honest, and easy to communicate with. Call us today you'll be pleased you did. Thank you!
"They did a wonderful job. They explained everything beforehand, answered all of my questions, and they were considerate of my home. The work was done in a timely manner, and it was completed right the first time!"
K F on April 2025
We invite you to experience a tradition of customer satisfaction that will exceed your greatest expectations. Our professionalism and quality workmanship will accurately reflect your taste and lifestyle. From conception to completion, we work with you until the job is done. We are ethical, honest, and easy to communicate with. Call us today you'll be pleased you did. Thank you!
"They did a wonderful job. They explained everything beforehand, answered all of my questions, and they were considerate of my home. The work was done in a timely manner, and it was completed right the first time!"
K F on April 2025
Horizon Services (MD), LLC, is the regions largest and most well respected plumbing, heating and air conditioning company, with nearly 600 employees serving tens of thousands of homeowners throughout Delaware, Southeastern Pennsylvania, Southern New Jersey and Northeastern Maryland. After a quarter of a century in business, Horizon Services (MD), LLC, remains fully committed to setting the industry standard for customer service, installation and focusing on things that are important to busy homeowners.
"Quick service"
Charles P on May 2025
Horizon Services (MD), LLC, is the regions largest and most well respected plumbing, heating and air conditioning company, with nearly 600 employees serving tens of thousands of homeowners throughout Delaware, Southeastern Pennsylvania, Southern New Jersey and Northeastern Maryland. After a quarter of a century in business, Horizon Services (MD), LLC, remains fully committed to setting the industry standard for customer service, installation and focusing on things that are important to busy homeowners.
"Quick service"
Charles P on May 2025
Here at Weather Masters we pride ourselves on affordable, reliable and honest service. With free replacement estimates and competitive service rates, we do our best to keep you and your bank account comfortable.
"Great folks to work with"
Tom H on September 2023
Here at Weather Masters we pride ourselves on affordable, reliable and honest service. With free replacement estimates and competitive service rates, we do our best to keep you and your bank account comfortable.
"Great folks to work with"
Tom H on September 2023
Supreme Service Today is a trusted business offering Heating Cooling and Plumbing Services, and our success is based on our dedication to meeting the needs of our customers through honesty, dependability, and integrity. Our experiences lies heavily in both residential and commercial maintenance, installation, and service. We provide 24 hour emergency service to better serve our customers' needs. Our technicians are courteous, knowledgeable, and will make your needs their #1 priority. We look forward to the opportunity to doing business with you.
"We met with a few HVAC installers and Supreme Air quoted the lowest prices and gave us 3 options to choose from. No games, no pressure tactics, and no unexpected charges. They were very prompt, professional, and did a great job."
Jan and Jeremy P on July 2021
Supreme Service Today is a trusted business offering Heating Cooling and Plumbing Services, and our success is based on our dedication to meeting the needs of our customers through honesty, dependability, and integrity. Our experiences lies heavily in both residential and commercial maintenance, installation, and service. We provide 24 hour emergency service to better serve our customers' needs. Our technicians are courteous, knowledgeable, and will make your needs their #1 priority. We look forward to the opportunity to doing business with you.
"We met with a few HVAC installers and Supreme Air quoted the lowest prices and gave us 3 options to choose from. No games, no pressure tactics, and no unexpected charges. They were very prompt, professional, and did a great job."
Jan and Jeremy P on July 2021
Pipeworks Plumbing and Services, is a rapidly growing and local Heating, Air Conditioning, and Plumbing company with a focus on residential and light commercial needs. In fact, we are more than just an HVAC company - "we are in the people business servicing Heating and Air Conditioning needs". We work hard to build trust and maintain an exceptional experience for our customers building life-long relationships one day, one customer at a time.
"Chase did a great job repairing a failed pipe that splashed water into our home. He carefully examined every aspect of the problem, determined what needed to be done, fixed the problem and tested the pipes to make sure everything worked -- and all of this at a very reasonable price. We've been using PipeWorks for several years to deal with plumbing issues and they've provided great service at reasonable rates. We'll continue to contact them when we have a plumbing problem."
Bill W on May 2025
Pipeworks Plumbing and Services, is a rapidly growing and local Heating, Air Conditioning, and Plumbing company with a focus on residential and light commercial needs. In fact, we are more than just an HVAC company - "we are in the people business servicing Heating and Air Conditioning needs". We work hard to build trust and maintain an exceptional experience for our customers building life-long relationships one day, one customer at a time.
"Chase did a great job repairing a failed pipe that splashed water into our home. He carefully examined every aspect of the problem, determined what needed to be done, fixed the problem and tested the pipes to make sure everything worked -- and all of this at a very reasonable price. We've been using PipeWorks for several years to deal with plumbing issues and they've provided great service at reasonable rates. We'll continue to contact them when we have a plumbing problem."
Bill W on May 2025
If you’re replacing an old AC system with a new unit, you can usually clean and repair the old ductwork without having to conduct a full replacement. Cleaning HVAC ducts typically costs around $400, while repairs range from $200 to $1,000. In contrast, installing new ductwork can range from $1,000 to $5,000, making it far more costly than cleaning or fixing existing ducts. HVAC installation costs an average of $7,000 to replace a full system, so staying on top of maintenance and repairs is important.
AC cost efficiency depends on the size of your space and your long-term plans for your home. If you only need to cool a small area, a portable AC unit has a low upfront cost. Heat pumps are typically the most cost-effective option if you want to cool an entire home or improve the resale value. They provide strong cooling while being energy-efficient, which saves you money on your utility bills compared to most other AC types.
Installing a central AC unit typically takes four to eight hours if your home already has ductwork in place. However, if new ductwork needs to be installed, this can add another one to two days of labor to your project.