Exxel Mechanical Services

Owings mills HVAC, Commercial HVAC and Residential HVAC

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(443) 821-1040


Frequently Asked Questions

Why should I perform preventive maintenance?

This question is twofold. You’ll want to perform preventative maintenance to protect your warranty and make sure the system lasts to full potential.

Should I have my equipment serviced?

Yes, we recommend that you get your equipment serviced annually.

What size heating and air conditioning system do I need?/What is the proper size HVAC system for my home?

The size of your system really depends on your home and your needs. To help you make this decision we offer free in-home energy consultations. We will perform load calculations to confirm we are properly sizing your new equipment. Feel free to give us a call to schedule your consultation today!

What type of heating and air conditioning system should I get?/How can I find the system that’s right for me?

To find the perfect heating and cooling system for you we recommend one of our free in-home energy consultations. Feel free to give us a call to schedule your consultation today!

What is the best way to heat and cool my home?

The best way to heat and cool really depends on what fuels are available at your home.

What indoor air quality (IAQ) solutions do you offer?

We offer Merv. 11, Merv. 16 and Air Purification.

Will I need a building permit?

Yes. A permit is required on all equipment installations. We provide all permits required from mechanical to electrical (if applicable) and gas piping (if applicable).

Why should I purchase a new heating or air conditioning system?

You should purchase a new heating or air conditioning system so that you can maintain optimum comfort year round.

Should I cover my outdoor unit in the fall and winter?

No, since units are designed to be outside they do not need a cover.

What is the most efficient way to run my heating and cooling system?

The most efficient way to run a heating and cooling system is to just leave it on. Take advantage of your programmable thermostat where you don’t have to worry about turning the system off or on, just let the programming do the work.

What is inverter or variable speed cooling?

An inverter and variable speed cooling are two different types of compressors.

What is modulating heating?

Modulating heating is variable capacity heating used in fossil fuel burning appliances. The draft induction motor will rev up or down based on the need for heat, and the amount of fuel needed for the appliance to burn efficiently will be regulated by the control valve to correspond to demand.

Should I zone my house?

A zoning system can improve air distribution to your home or business. Most situations do not necessitate a zoning system. We do offer a diverse line of zoning products, but customer should be aware that the duct infrastructure will need to be replaced at the same time.

What is a “properly matched” system?

This all depends on size of house and duct work.

What is AFUE?

AFUE is efficiency rating of the fuel burning appliance. 80% AFUE rated appliances use a metal exhaust vent and loose 20% of the heat through combustion in the exhaust gases that are vented outside.

High efficiency equipment (90% +) use a PVC vent, and heat loss through the venting is minimized. This type of equipment uses a secondary counter flow heat exchanger, and exhaust gas temperatures are so low, that they form condensation.

What is HSPF?

HSPF stands for Heating Seasonal Performance Factor. This rating is associated with how much heat a heat pump is able to bring into the home during the winter season.

What is AHRI?

AHRI is a website that gives ratings on the equipment.

What is SEER?

This is the Seasonal Energy Efficiency Rating. This is associated with the Air conditioning systems performance averaged throughout the entire cooling season.

What is EER?

This rating correlates to the amount of energy the air conditioner uses at peak energy loads.

How often should I check/replace/clean my air filter?

You should check your standard 1″ air filter anywhere from 1 months-3 months depending on the filter and where you live. Larger families and pets tend to make filter changes more frequent. Air Cleaners with 5″ pleats usually are good for 6 months to a year.

How does the phaseout of R-22 (Freon) affect me?

Since R-22 has been phased out, parts and refrigerant are hard to come by which often make them quite expensive.

Should I purchase a new system with R-410A refrigerant?

Yes, when it comes time to repair your system, parts and refrigerant will be a lot more reasonably priced.

What is the difference between R-22 and R-410A refrigerants?

R-22 is the older refrigerant used in air conditioning units. R-410A is not only newer, but it is also more environmentally friendly.

What is two-stage cooling?

In two-stage cooling there’s a low stage and high stage.

How long will the system last?

Depending on general maintenance, systems can last anywhere from 10-20 years. To last as long as possible, we highly recommend an annual general maintenance.

What is the minimum energy efficiency standard for air conditioners in MD?

The minimum energy efficiency standard for air conditioners in MD is 14 SEER.

What should I know about changes in refrigerants?

R-22 is no longer available, R-410A is the standard replacement.

How does a variable-speed furnace benefit me?

A variable-speed furnace benefits you on the cost and noise of running the system.

How will I know when it’s time to replace my Heat Pump?

It is time to replace your heat pump when it won’t work anymore, it’s 15 years or older, or if it’s a R-22 unit.

My present Heat Pump does not keep us comfortable. Should I replace it with a larger one?

Not necessarily, larger doesn’t always mean better. You would probably want to look into getting a more efficient variable speed system.

Can I repair my own Heat Pump?

No. We recommend leaving this one to the professionals. If your heat pump needs to be repaired feel free to give us a call at 443-821-1040

Can I put a cover over my outdoor Heat Pump?

No. If you put a cover on your heat pump and the system turns on, the system will no longer work.

What is a heat pump?

A heat pump is a system that can reverse refrigerant flow to either heat or cool a controlled space.

How often should I have my comfort system serviced?

Here in the Northeast, it is recommended you have your comfort system serviced twice per year, preferably in the spring and fall. This will help ensure that your comfort system is running as efficiently as possible during the heating and cooling seasons. At EXXEL we offer a Precision Tune Up service which will take care of all of your system’s maintenance needs.

If I know the size of my current furnace, can I assume that a new furnace will be sized the same?

Not necessarily. Just because a certain size of furnace or comfort system was previously installed in your home does not mean that system was correctly sized for your home. When it comes to home comfort systems, it is extremely important to size the system correctly. An improperly sized system can cause problems with comfort and efficiency, and could also lower the useful life of your equipment.

A different HVAC company provided a bid for a comfort system replacement without performing a heat loss calculation on my home. Is a heat loss calculation necessary?

Unfortunately, not all HVAC companies are made equal, and not all of them do an adequate job of correctly sizing a system. Beware of any HVAC company that offers to replace your furnace, air conditioning unit, or comfort system without doing a proper heat loss calculation. Simply counting registers is not enough to ensure proper sizing! In many instances, especially with today’s variable speed and modulating technology, previous systems have been oversized compared to what is needed for the home. Not only does a smaller system cost less to purchase and install, but a correctly sized system will run at optimal efficiency and will provide the greatest comfort.

How often should I have my Air Ducts cleaned? How much does duct cleaning cost?

The frequency of duct cleaning varies depending on the home and the preference of the homeowner. Typically, every 5 years is sufficient. There are a few things to consider when thinking about how often to have your ducts cleaned:

  • Do you have pets that shed a high amount of hair and dander?
  • Do you have smokers in your household?
  • If anyone in your household has allergies, you may want to have your ducts cleaned more often.
  • If you just moved into a home, it may be a good idea to have the ducts thoroughly cleaned.
  • After a home remodeling, a heavy amount of dust and debris can be generated during a renovation.
A thorough duct cleaning will usually cost between $300 and $500, depending on the size of the home. Beware of companies offering cut-rate duct cleaning services. This is a well-known bait and switch tactic, and you could end up paying much more than you expected, or the company may not perform a proper duct cleaning. The Better Business Bureau has issued a warning about such services.

I recently had a high-efficiency comfort system installed. Why am I not saving as much energy as I thought I would?

There are several possible explanations for this:

  • The behavior of the members of your household may have changed. Examples may be turning the heat up higher for a longer duration, leaving windows open, taking longer showers, etc.
  • Outdoor temperatures and weather may be different this year than last year
  • You added air conditioning when you previously did not have it in your home.
  • Energy prices may have risen.
  • You may have a problem with your ductwork or insulation.
  • Your system may not have been properly installed.
  • Your system may not have been properly sized for your home before installation.

Why should I do business with EXXEL Mechanical Services?

We have been serving the Central Maryland area since 2003. We are a smaller family owned company, focused on customer satisfaction. We are certified installers of Lennox Signature, Carrier Infinity, and Mitsubishi Hyper heat. Fully Licensed and insured, unlike some of our competitors. If you are interested in a new comfort system, you will receive the quality and attention to detail that only a small local business can provide.

What factors should I consider when upgrading or replacing my comfort system?

Here are a few questions you should ask yourself:

  • How long do I plan on living in my home? The answer to this question will affect the return on investment of any high-efficiency system.
  • How concerned am I about my family’s carbon footprint?
  • Is having a comfortable home a high priority for me and/or my family?
  • Does anyone in my family suffer from allergies? If so, you may consider exploring some Indoor Air Quality products such as improved filters, air cleaners, or UV air purifiers.

How can I be sure the air in my home is safe from carbon monoxide pollution?

Carbon monoxide, also known as the “silent killer,” is a big problem. A failed natural gas furnace or other appliance can release poisonous CO gas into your home. The problem is that carbon monoxide is colorless and odorless, meaning that without proper precautions, you won’t know if there is a problem. We offer low-cost accessories that can alert you if you ever have a problem with carbon monoxide in your home, helping you breathe easier!

How can I increase the life of my comfort system?

Of course, like any machine, proper maintenance is important in maximizing the life of your comfort system. We recommend getting a Precision Tune-Up twice per year. These services are included with our Gold and Silver memberships.

It is also important to ensure that your comfort system is properly sized for your home when it is installed. Improper sizing can lower the useful life of a comfort system, cause it to run at a lower efficiency level, and reduce the comfort level of your home. Make sure your HVAC contractor does a proper heat loss calculation before they install your system!

What benefits does an upgraded thermostat provide?

Today’s thermostats offer a wide range of energy saving and comfort options. Most thermostats today give you the ability to program them for optimal comfort and efficiency. Higher end models can provide “energy monitoring” features, showing you which appliances in your home are using up more energy, and at which times of the day. Give us a call or ask your comfort advisor about thermostat options if you would like more information.

Is your question not on the list? Feel free to contact us 443-821-1040. Our regular business hours are Monday-Friday 8am-4pm