Most updated central air conditioned homes have a new air conditioner split system meaning the ac is broken up into parts.
Conditioned attic systems.
Hpca is a below roof deck engineered insulating system that dramatically lowers attic temperatures brings ducts into conditioned space and.
These connect by a refrigerant line and a.
Seems to me the only reason to create a conditioned attic is to bring the hvac system and ductwork into the thermal envelope of the home.
Housing industry has been to locate hvac systems in unconditioned attics but this is highly inefficient.
Most people desire cool homes for sleeping and bedrooms are often located on the upper levels.
Well mainly it s a way to save space.
A fundamental requirement of an unvented attic assembly is the use of air impermeable insulation on the underside of the unvented roof to prevent air infiltration and exclude airborne moisture from the attic.
So why put an hvac system up in the attic at all.
The system consists of two types of units.
The condenser in your air conditioner works hard to get rid of heat and pressurize refrigerant for the return trip through your house.
Most of the heat generated in your home is coming from the roof and the attic adding heat gain to the upper levels.
This is very difficult for the system and the upper levels of most air conditioned homes experience unsatisfactory cooling.
Among the early promoters of conditioned attics was joe lstiburek a principal of the building science corporation.
Unvented conditioned attics were quite rare before the 1980s.
Creating a conditioned attic without a hvac unit in the attic.
If there is no hvac in the attic why not just air seal and insulate at the attic level much easier and less expensive.
An outdoor unit which houses the fan condenser and compressor and an indoor unit which holds the evaporator and fan.
An edited version of this insight first appeared in the ashrae journal.
The attic space becomes indirectly conditioned as a result of the air leakage heat transfer and vapor diffusion through the ceiling.
One outdoor condenser and the air delivering indoor units which you have at least one of or maybe four.
Lstiburek s enthusiasm was rooted in his desire to bring attic ductwork inside a home s thermal envelope.
A lot of the blame for that goes to me and for that i am sorry.
Unvented conditioned attics the preference for a large segment of the u s.
Attic hvac systems save space.
The right terms should have been conditioned attics and conditioned roofs.