Ask the Expert

Ralph Schletter, owner of Marcucci Heating and Air Conditioning Inc., answers your most frequently asked questions.

Is it OK to install the furnace in the attic?

Yes. It is very common and makes the installation quieter.

Can I add a high efficiency filter to my existing furnace?

Yes you can with a simple retrofit in most cases. They offer 10 MERV 85% and 16 MERV 95% units.

Is it important to have ducts sealed and insulated?

Yes. The new standard is 15% air leakage in supply ductwork.

Can I install a 95% unit if I have old equipment now?

Yes you can with a simple flue and condensate drain retrofit in most cases.

Is zoning my house possible?

Yes. If the supply ductwork can be separated for zones or areas that you want conditioned separately.

Can I install A/C if I only have limited space for an outdoor unit?

Yes, there are options for Slimline condensing units which are far narrower than standard cubicle units and allow for placement in much tighter spaces where property lines and side yards are limited in space.

What is the difference between 80% and 95% furnaces?

80% furnaces use a metal vent pipe. 95% furnaces use a plastic vent pipe and have water as a byproduct.

Is one brand better than another?

In some cases but the most important thing is that it is installed correctly for proper operation.

Do they make thermostats that can operate every day independently?

Yes they do, but it is more common to regulate weekdays & weekends.

What is the difference between 13 seer and 15 seer?

Seer is the efficiency. The higher the number, the higher the efficiency.

Is a HEPA filter better than a MERV filter?

MERV and HEPA are the rating systems. They are both good quality filters for allergies and asthma.

When it gets hot the A/C doesn’t seem to cool fast enough. Why is that?

Try turning it on sooner in the day. A/C systems are designed to cool at about 20 degrees per cycle. Some houses might need more time depending on insulation.

My furnace turns on and off constantly. Why is that?

You might have a plugged air filter or air flow restriction. Call for service to be sure.

I changed my filter and now my furnace does not work.

Check the door to see if it is installed properly. There is a safety switch that might not be depressed.

Is it better to have vents in the floor or ceiling?

It doesn’t matter too much. The best location is where they are the least obstructed so the air can flow freely.


  • HVAC – Heating, Ventilation, & Air Conditioning
  • AFUE - Annual Fuel Utilization Efficiency. This rating indicates the percentage of fuel that is consumed by the unit and converted into heat for your home. For example: if you have a 95 AFUE furnace, 95% of the fuel is converted into heat, while only 5% becomes unburned exhaust remaining unused.
  • BTU – British Thermal Unit. This rating represents how much heat is given off when the fuel is burned in your unit and also refers to how much heat is extracted when your home is being cooled.
  • Ton – In HVAC terms, it is a measurement unit associated with the heating/cooling capacity of a system. 1 ton is equal to 12,000 BTU’s of heating/cooling per hour.
  • Split System – The most common residential application for heating and AC. The condensing unit for the air conditioner will be placed outside the home while the furnace and coil are typically installed within the home.
  • Packaged System – A combination heating & AC unit in which both the entire air conditioning system and the furnace unit reside within the same cabinet. These units are most typically found on rooftops of buildings or homes.
  • SEER – Season Energy Efficiency Rating. The higher the rating, the more efficient the unit. Air Conditioning and heat pumps use the SEER rating system.
  • Compressor – All air conditioners and heat pump systems have a compressor within the outdoor unit which pumps refrigerant. The compressor ensures adequate refrigerant pressure remains in the refrigerant line to satisfy the capacity of the system.
  • Condenser Coil – The condenser coil resides within the outdoor unit and its function is to allow heat to escape from the refrigerant by allowing air to blow over the coil.
  • Downflow Furnace – A furnace configuration that pulls in return air from the top of the unit and forces the heated air out the bottom.
  • Upflow Furnace – A furnace configuration that pulls in return air from the bottom of the unit and forces the heated air out of the top.
  • Horizontal Furnace – A furnace configuration where the unit is mounted on its side, it pulls in return air from one side of the unit and forces it through the other side. These units are most typically found located in crawl spaces or attics due to the limited vertical height in those environments.
  • Ductwork – Pipes that distribute the heated or cooled air throughout your home.
  • Zoning – A method of distributing the air to specific portions of your home. For example: In a two story home: the upstairs could be designated zone 1, while the downstairs are zone 2, and your single furnace can push air to each zone independent of one another.
  • Damper – Used in ductwork to control the flow of air within the duct system, commonly found in multi-zone systems (See zoning above).
  • Humidity – A measure of the amount of moisture present in the air. Air conditioners remove humidity as the air is processed within the system for extra comfort.
  • Thermostat –A devise used to control furnace or air conditioning system operation. This device is also typically the brain center for air temperature data collection and related computation for preferred equipment operation.
  • MERV –The minimum efficiency reporting value is the standard comparison of the efficiency of an air filter. The MERV scale ranges from 1 to 16, with 16 being the most efficient. This system measures a filters ability to remove particles from 3 to 10 microns.
  • Puron Refrigerant- This is a new, chlorine free, refrigerant that is considered to be more environmentally sound than the R-22 refrigerant it replaced. The federal government banned any new manufacturing of R-22 refrigerant in 2010. Puron refrigerant is now considered to be the industry standard.
Contact Us

2400 Bay Rd, Redwood City, CA 94063, United States
Phone:+1 650-556-1882

BBB Acredited Since 1974 with an A+ Rating!

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