Attic Furnace Duct Design

Sketch a rough design using a central supply duct from the unit to the opposite end of the house with branches forking to each outlet.

Attic furnace duct design.

To promote balanced air circulation through the supply ducts home and return ducts the ductwork should be simple in layout accurately sized sealed insulated in unconditioned spaces and installed in the right places. A furnace can suffer from a drop in energy efficiency if it s in an unconditioned space such as an attic. The purpose of residential ductwork design is to properly distribute the airflow produced by your heating cooling system to your house. Well mainly it s a way to save space.

Situate the air handler close to the center of the layout to minimize the length of ductwork spans. Make sure your hvac contractor follows these duct design best practices and principles using manual d. A furnace in the attic is a design that works for all homes. One on a concrete slab.

Most of the issues that furnace might experience in an attic are due to extremely cold weather in this poorly insulated space. Continuing education and development inc. Hvac how to size and design ducts. This involves return air unconditioned coming into the heating cooling system.

Certain types of air conditioning systems like heat pumps require larger ducts. So why put an hvac system up in the attic at all. The layout and installation of the duct system will incorporate these basic principles of good ductwork design. You ve got to know how much heating and cooling you need for each room in btu hr.

Then by heating cooling that air delivering the newly conditioned air to your home. An outdoor unit which houses the fan condenser and compressor and an indoor unit which holds the evaporator and fan. Consider your equipment type and supporting systems. If your system includes air purifiers with activated charcoal filters these also affect air flow and may require larger ducts and or additional air returns.

If you don t have a crawl space or a basement then it can be a challenge to place a furnace on the ground floor of the structure. Designing a duct system is important but there are a few critical steps that come first. High efficiency furnaces aren t usually recommended for an attic. Most updated central air conditioned homes have a new air conditioner split system meaning the ac is broken up into parts.

Number one is the heating and cooling load calculation using a protocol like acca s manual j or the ashrae handbook of fundamentals. 9 greyridge farm court stony point ny 10980. Adapt the design to the type of unit.