If your furnace draws combustion air from inside the house you are using air that you have already heated.
Ducted attic gas furnace make more efficient.
Most of the issues that furnace might experience in an attic are due to extremely cold weather in this poorly insulated space.
High efficiency furnaces offer 90 or more afue.
If turning on your furnace makes you cringe in anticipation of high energy bills use these five steps to help you save money and increase your furnace efficiency.
Higher efficiency can be gained in a gas furnace with an alternative to the traditional pilot light such as an intermittent direct spark or hot surface ignition.
It is much more efficient to use outside air for combustion air.
5 steps to improving your furnace efficiency.
A furnace can suffer from a drop in energy efficiency if it s in an unconditioned space such as an attic.
So a 95 furnace is more efficient than an 80.
Assuming that the alternative to mini splits would be an 95 gas furnace with r 8 ducts in the attic and gas is 1 25 per btu it looks to me like i would need at least an 11 hspf heat pump if electricity rates are going to be 20 per kwh.
The trick to the installation of a gas furnace in an attic space is routing the condensate drain from the attic down through the core of the house to the basement.
Ideally i would want higher because i know that hspf usually drops as temperature drops.
If someone was going to seal the attic then it would make much more sense to build a closet around the furnace that gives adequate ventilation to the outside.
Hvac system problems can go undetected.
You must have more holes creating in your ceiling to install the duct work and move the hot air through your home if you opt for a furnace in the attic.
This process is the only way that you can create a thermal envelope that can provide a comfortable indoor environment throughout the year.
Leaky seals in unconditioned vented attics can effectively turn an efficient 15 seer unit into a 12 meaning it s much less efficient.
The higher cost of a more efficient gas system will most often be offset by lower fuel costs in regions with harsh winters.
In it the authors argue that attic ducts kill home efficiency they say that studies show a 20 percent energy use increase for homes with attic ducted units.
Check replace your furnace filter.
As we get deeper into winter the cold weather means an increased use of your furnace.
A standard efficiency furnace provides 80 annual fuel utilization efficiency afue.
There is a common misconception that this is not possible for high efficiency furnaces.
90 of the attic would get the insulation benefits of the spray foam and then there s other options to help with the new furnace closet in the attic.
These days 95 afue is a common rating among new gas powered furnaces.
There are rarely instances when we will advise against an attic installation.