09 Heating, A/C & Ventilation


This list of selections serves as a supplement to the Construction Documents (CD’s). Some of the selections below may be difficult to find or omitted on the CD’s. Check the CD’s for consistency with this list. Clarify with your contractor which document takes precedence for any inconsistencies.



The three most common options for delivering heat throughout a house are the following: (1) natural gas powered furnace pushes hot air through ducts; (2) natural gas powered boiler with hot water tubes radiating through the floor; the main drawback of this heating system is it requires a separate system to deliver air conditioning. (3) electricity powered air source heat pump pushes hot air through ducts. Another type of heat pump is a ground source heat pump, also call geothermal, which is less common than the air source heat pump because it is much more expensive to install. The geothermal heat pump is more efficient and sustainable than the electricity powered air source heat pump.


Select Manufacturer and model # of furnace _____________________________

Select Manufacturer and model # of boiler_______________________________

Select Manufacturer and model # of heat pump __________________________


Air Conditioning

There are two common air conditioning systems: (1) Central air conditioner delivers cool air via ducts; (2) Ductless mini-split air conditioners in which each room or zone has its own air handler, thus it is easier to meet the varying comfort needs of each room.


Select Manufacturer and model # of air conditioner __________________________



Select color of floor / wall / ceiling diffusers

__ White                     __ Brown                     __ Other color: ___________


Whole House Ventilation

Most building codes require a whole house mechanical ventilation system for new houses. There are a variety of types of these systems including: (1) exhaust (2) supply (3) balanced (4)




energy recovery ventilator (ERV) and (5) heat recovery ventilator (HRV). At minimum, the code requires this system to provide outdoor air at a consistent rate. Your heating contractor should be able to provide pricing and explain which system is best for your house and your climate. Both the ERV and HRV are common in the north-east U.S. where winters are very cold.


Select whole house ventilation system, manufacturer and model #__________________


Bathroom Ventilation

Bathrooms and small compartments for a toilet only, require either an operable window or an exhaust fan. Check your construction drawings to make sure at least one is included. If you elect to install an exhaust fan, you will need to determine its capacity, typically measured in cubic feet per minute.

Select Manufacturer, model # & capacity exhaust fan ___________________


Appliance Ventilation

Several common appliances in the house are required to be exhausted in accordance with the manufacturer’s instructions and the building code. In many cases, there is a minimum distance between the termination of an exhaust duct and a window opening or property line. Provide all appliance selections and specifications to the contractor so that the necessary exhaust systems can be installed as early as possible in the construction process.


Range hood

Range hoods are popular upgrades from the lesser expensive but popular option of a microwave above the range. The exhaust capacity of a microwave is relatively low compared to a range hood. Range hoods come in a wide variety of sizes with varying exhaust capabilities. The size and length of the exhaust duct from the range hood to the exterior may vary from one model to another.



The exhaust requirements for fireplaces vary considerably. The exterior termination of the exhaust duct may have a minimum and maximum height relative to the fireplace box. First determine whether the fireplace box will rest on the subfloor or will be raised up.


Clothes dryer vent

Rigid metal ducts should exhaust moist air to the exterior. Flexible ribbed vents used in the past should no longer be used.


Once the rough framing is complete, the rough mechanical can be installed. Review options with your Contractor and make selections well before it is time to start the rough heating stage of construction. Find out if your heating or AC equipment may be long-lead items. Some municipalities require a robust HVAC system design report for loads, equipment and ducts. This report, often referred to as “Manual J Calculations” may be completed by the HVAC contractor or an engineer.


Review Scope Of Work with Contractor

  1. Determine diffuser and return air grill locations for heating and/or AC: mark locations on subfloor, wall studs or ceiling joists.
  2. Verify color of diffusers and grills.
  3. Review location for equipment. The furnace is typically located in a basement, while the AC condenser is typically located outside. If you are installing a mini split system, the outdoor equipment can be much larger than a typical AC condenser, so verify the size and make sure you can accommodate it.
  4. Determine and mark location of thermostat.
  5. Verify which materials will be provided by HVAC installer
  6. Verify who will install range hoods, fireplaces, bathroom fans, microwave, and other equipment requiring exhaust ducts
  7. Verify location of exhaust ducts and termination at exterior for range hoods, fireplaces, bathroom fans, microwave and who will install these ducts and terminations. Building codes may require minimum distances from windows or outside air intakes.
  8. Verify timing of installation of exhaust terminations and coordinate with roofing and siding installation.
  9. Discuss targeted completion date for operational heating system as it relates to seasonal demands.
  10. Verify length of warranty for parts and labor.

Inspect For Correct Installation

  1. Verify ducts are properly insulated, taped and sealed.
  2. Make sure all ducts and exhaust fans to be hidden, are installed prior to drywall.
  3. Provide temporary protection from dust at all diffusers and grills.
  4. Test the heating and cooling system. Make sure warm air is being distributed from all diffusers when thermostat is calling for heat. Make sure cool air is being distributed from all diffusers when thermostat is calling for cooling.
  5. Ensure that the contractor balances the heating and cooling system by using dampers and controls. Consider using thermometers in each room to determine if each room is obtaining a similar temperature.