How Your Attic Affects HVAC Efficiency: Unseen Impacts on Heating and Cooling
When your HVAC system is in an attic, heat gain from the sun’s rays is detrimental. You also have the fact that hot air rises. In the winter, heat is going to travel up the floors in your home to your attic. You’ll lose heat through even the tiniest gap.
Your attic’s design does impact your heating and cooling system. Before you lose too much money to a drafty or hot attic, learn how to ensure your HVAC system functions properly with tips from our experts at Air Blue.
Understanding Heat Transfer
Energy.gov defines heat transfer as “the transfer of thermal energy due to a temperature difference.” There are three types of heat transfer.
- Conduction – The transfer of heat from one object to another as it travels through the object, such as heat going from soup in a pot to the end of a metal spoon.
- Convection – The movement of heat in an upward motion, such as the heat from a fire going up a chimney and into the outdoor air.
- Radiation – The movement of heat from a warmer object to a cooler one, such as the warmth of the sun heating your cold hands.
How does that heat transfer impact your attic? In the summer, the heat from the sun warms the roof (radiation), which transfers to the attic air (conduction). This makes an AC system work harder to keep the rooms cool enough. Ventilation is important.
In the winter, warm air rises (convection), and it will leave a drafty attic. Your system must work harder to keep the rooms heated to the appropriate temperature.
Fixing any issues that impact heat transfer is key to a comfortable home and efficient HVAC system. There’s more to this than you might think.
Common Attic Problems Affecting HVAC Efficiency
Your HVAC system needs to be able to capture heat in your rooms through the coils and coolant within them. That heat is brought outside where it’s released. The coolant travels back inside where it releases cool air, which is blown into the ducts to cool your home. That’s the AC part of an HVAC system. In the winter, the reverse happens.
For this to work, you can’t have heat transfer making it hard for the system to capture cool air or warm air. If the system works harder, it strains the components. That wears out your system faster than necessary, and it also drives up your electricity or gas bills.
At the same time, you need ventilation that removes humidity. If humidity builds up, you’ll get mold and mildew. Get that mold and mildew in your insulation and it spreads. Mold impacts your health and can lead to severe allergies and even asthma.
Airflow is important for ventilation. If you store loads of items in your attic, it blocks airflow. Clean out your attic of unwanted items and donate or sell them. Before you store something in your attic, make sure it’s an item you will use again. Clutter isn’t something you should allow to build up. It just creates more work in the future.
Finally, not having your system cleaned and maintained regularly also impacts efficiency. Have your system cleaned professionally every year. Ducts should be inspected every few years. Change your HVAC system’s filters every few months. Inspect them monthly to ensure there’s not a lot of dust and grime building up on them. Change them before they get overly dirty.
Insulation Is Important, But It’s Not the Only Thing
Insulation is important for minimizing the effects of heat transfer on your HVAC system. When your attic is properly insulated, it keeps hot air from leaving your attic in the winter. It also prevents heat gain in the summer by buffering the transfer from the sun’s rays.
When you’re keeping excessive humidity and heat out of your attic, your utility bills are lower. Your rooms feel as cool or warm as you want them to be. Plus, your HVAC system works like it’s supposed to. It’s not rapidly cycling on or off and wearing out components faster than necessary. You’ll get more life from your system.
Insulation is important, and you have to consider what type of insulation you add to your attic walls and ceiling. Check the fire rating on it to ensure it’s fire retardant in case of a fire. Options are:
- Cellulose – Cellulose insulation is shredded cellulose particles that are blown into the space using specialized equipment. It’s best for enclosed walls and cavities.
- Fiberglass – Fiberglass is often in rolled insulation that requires gloves and eye protection as it can irritate the skin and eyes. It’s an affordable option and easy to do yourself.
- Foam Boards – Insulation boards are another good choice for DIY. You have to cut them to fit the space, but it’s worth it as they insulate well.
- Reflective System – Rolls of silver bubble wrap-style insulation are lightweight and easy to work with. You may need multiple layers to get the best level of insulation, which is why they’re often used between framing.
- Spray Foam – Foam insulation is blown onto the walls and ceiling to form a layer that sticks to the service. It’s a good choice for attic floors as it can expand to fill spaces.
When you’re insulating an attic, you need to insulate any walls, ceilings, and beams. Aim for between the studs, joists, and rafters. You want to seal up all gaps, even the smallest ones, to keep air from escaping or entering.
Because attics also get humid, ventilation is equally important. Attic vents and fans ensure that humidity levels are controlled. You also want to make sure that you have your HVAC system inspected regularly. You don’t want humid air leaking into walls and increasing humidity levels unnecessarily.
Hire an Expert in HVAC for a Professional Assessment
The sun is a very powerful source of heat gain, and it reduces the efficiency of your HVAC system. Insulation is key when it comes to limiting the negative effects of heat gain on attic space. Insulation also keeps warm air from escaping out of the roof. Hire an HVAC professional for an assessment of your HVAC system’s efficiency and get additional tips that help you.
Make sure it’s in top condition by having it tuned up regularly. If it’s an older system, look into the extensive discounts and tax credits that are available for energy-efficient HVAC systems. Air Blue Heating and Cooling offers discounts on furnace tune-ups and furnace and AC installations, contact us today to learn more!
