We have been the part of HVAC industry for a number of years. As such, we have overseen the trends of old and witnessed the evolution of industry practices –and have continued facilitating our customers with reliable heating and air conditioning service in Huntsville, AL accordingly. We have serviced and repaired HVAC units in a vintage Victorian house, and we have installed central air conditioning units in an open living designed residential property.
Leveraging our experience in the field, today, we decided to answer a question that our customers and clients frequently ask – while seeking guidance on the subject of HVAC installation:
Can we install HVAC ducts in an unconditioned attic?
Yes you can, depending on the details of the individual case. But, as a standard industry practice, it is not advisable. Allow us to explain.
Avoid Installing HVAC Ducts in an Unconditioned Attic
We hope you at least have a vague recollection of your elementary school physics classes, because, we will be using those basic concepts of old to explain why it is not advisable to install HAVC ducts in an unconditioned attic. Even if you don’t remember them, you will find the following explanation easy to understand.
What happens when you immerse a fluid (let’s say, its temperature is T1) into another fluid (the temperature of this fluid is T2) or bring them in close contact with each other?
Obviously, if T1 and T2 are not equal, the heat exchange will take place between the two fluid bodies, with the heat flowing from higher temperature to lower temperature, until a uniform temperature is not achieved.
Now, this is exactly what is happening when you consider the fluid, running in the HVAC ducts, and the fluid which surrounds it—the ambient air. Assuming that you are running the air conditioner, the ducts will be carrying a fluid which is comparatively at a lower temperature as compared to the ambient air. Heat exchange will take place, there will be energy losses and hence, a reduced working efficiency. This is bound to happen.
But, when your air conditioning service contractor installs the ducts in an unconditioned attic—which is the most vulnerable area of your home with regards to changes in ambient temperature, the difference in temperature could be anything between 70°F to 100°F in summers. The energy losses become more significant and the heat flow is much greater. This should not happen. Add to that the leaks in your network of ducts and a large surface area of the deployed tubes – you are severely reducing the efficiency of your installed HVAC system.
After this, if you set the thermostat at 50°F, it is impossible that the vent terminals will be providing an air cooled at 50°F.
Summer or Winter – Our Advice Remains the Same
In winters, the opposite happens. The HVAC ducts are carrying a fluid which is at a higher temperature as compared to the ambient air present in the attic. Again, the difference in temperature is significant and you will be receiving an air which is not warm enough to keep your indoors comfortable.
Yet HVAC Contractors Do It – That Too in Different Configurations!
As a company which provides heating and air condition service in Huntsville, AL, quite often we come across attic based deployments, especially in homes which were constructed in late 1960s. The professionals providing heating and air conditioning service in Huntsville, AL, prefer the attic based deployment of HVAC ducts in two different configurations:
The High and the Higher!
High in the Attic
The attic’s temperature is already high when you compare it to the rest of the areas of your home. And with height, its temperature only rises further. This means that the ducts installed at a height in the attic are even more susceptible to significant energy losses and heat exchanges. Plus, they make it worse by installing an up flow furnace in the attic, for which the ducts need to be positioned at a higher elevation. Why they don’t opt for a down flow furnace? We talk about this here (hyperlink to blog titled, Assessing the Air Flow Profile of a Furnace: Upflow or Downflow?)
Higher in the Attic, Against the Roof Top
Other service contractors installing heating and ac units in Huntsville, AL secure HVAC ducts against the roof top, especially when performing installations in homes with vaulted ceilings. Here, not only the difference in temperature degrades the performance of the HVAC system but these ducts, at times, also displace the insulation. Although, some contractors do wrap fiberglass insulation around the duct system but it does not make any significant difference.
If, installing HVAC ducts in attic is not advisable then why do contractors do it?
Reasons Why an HVAC Professional May Prefer Installing Ducts in an Unconditioned Attic
It’s not because they do not have the knowledge, but professionals providing heating and air condition service in Huntsville, AL may exercise the decision when faced by certain restraints:
- Some homes do not have a basement or an additional storage space, where they can conveniently install the duct work. As such, an attic becomes their only option.
- Some homeowners do not have enough budget to permit a solution that routes through interior walls and floors. Running a flex duct through a wide open attic is a cheaper option for them.
- Some HVAC professionals may prefer to install HVAC ducts in the attic because it makes future maintenance and modification easier.
As a Homeowner, What You Can Do?
Well, there are few suggestions that we would like to propose:
- Firstly, you can hire a local company that provides reliable heating and air conditioning service in Huntsville, AL and ask them to design an integrated duct work system for your home. They would inspect the structure and propose a design that could conveniently integrate with the architecture.
- For those, who already have an attic based duct work deployment, if the budget permits, you can consult a local heating and air condition service in Huntsville, AL and get it replaced with a retrofit duct system.
- You can install insulation systems like spray foam insulation or a radiant barrier to keep your attic well insulated, hence, improving the working efficiency of the HVAC system.
We, at Jackson Plumbing, Heating and Cooling, provide customized HVAC solutions for homes and commercial properties. Our services include HVAC system installations and heating and ac repair in Huntsville, AL. Let us know how we can help you.