Are you having unexplainable HVAC issues? Or, is your HVAC system performing sub-optimally?

Well, HVAC issues are caused by so many things including vent blockage, worn-out filters, dirty coils, and thermostat problems and so on.

But what most people don’t know is that a home’s faulty foundation can also affect their HVAC unit.

Aside from providing a strong and stable structural base for your house, the foundation also plays a major role in your home’s temperature maintenance.

Because of this, modern houses often come with added tweaks to create a better and more efficient energy use profile. Some of these tweaks include better insulation, air sealing, and thermal envelopes just to mention a few.

Unfortunately, the same doesn’t apply to older buildings that are either damaged or lacking insulation. Therefore, it’s quite normal to see an old house spending more on heating and cooling than a new one.

If you own an old house or suspect that your damaged foundation is affecting your HVAC system, here are a few things you need to know.

How Foundation Problems Can Affect Your Home’s Heating and Cooling

Having a damaged foundation is almost every homeowner’s worst nightmare.

That’s because it not only threatens the structural integrity of your home but also a damaged foundation is not easy to fix . And that’s why it’s always advisable to monitor, maintain, and repair your foundation on time.

Regarding HVAC issues, there are a number of reasons why foundation problems could be the cause. Here are some of them:

1.) Lack of proper air sealing.

A damaged foundation makes absolute air sealing impossible. If you ask any home builder or a structural engineer, they’ll tell you that a tight building envelope always improves the efficiency of an HVAC system.

But, when there are a lot of gaps, cracks, and holes on the walls, windows, and doors, there will be a high possibility of drafts and temperature changes; both eventually affecting your home’s heating/cooling.

Now, despite your AC being faultless, this foundation-related problem can make your home’s atmosphere and temperature less comfortable and cozy, especially during extreme weather seasons.

2.) Sloping floors.

A sloping or unleveled floor can also indirectly affect your AC’s performance.

You may not know this but older houses are prone to floor issues. These issues, later on, evolve into bigger and more severe ones like cracked or crumbled foundations; common in homes with stone or brick foundations.

But, how exactly does this affect your HVAC system?

Well, it all starts with gaps between your floor and door jambs due to sloping; which allows conditioned air to leak through.

As time goes by, cracks start to form around your windows and doors creating more escape routes for conditioned air. And then you’ll start to wonder why your AC isn’t performing optimally.

Therefore, if you notice an increase in your utility bills coupled with sloping floors, you may need to get your home’s foundation inspected.

And once this is completed, the inspector will advise you on what to do or how to proceed in order to fix the problems (if any).

3.) Lack of insulation.

When you insulate your walls and foundation you increase your home’s ability to retain more heating or cooling.

This is great because it, in turn, increases your AC’s efficiency hence lowering your utility bills.

Now, the opposite is also true. Uninsulated walls and foundation allow for a fast loss of heating and cooling. Which results in your AC using up a lot of power trying to keep the temperatures at an acceptable level.

Insulation depends on a number of factors including the type of home, foundation, and its construction style.

For new houses, insulation is commonly done using concrete forms or blocks.

But, for older houses, retrofitting is always the best way to go. Here, the insulation is added to the interior walls/crawl spaces and also to the exterior. Some homeowners opt for rigid form boards that are placed around the perimeter of the foundation.

Unfortunately, retrofitting doesn’t come cheap and will depend on the build and structure of your home. But, if you have severe heating, cooling, or moisture problems, then this may be your best shot at fixing your AC’s performance shortcomings.

4.) Tilting walls.

When foundation issues become severe, you may start to notice tilting walls and increased cracks.

The tilting may sometimes lead to the separation of AC ducts from one another causing level and balance issues in your heating/cooling system.

When this happens, you are bound to notice a drastic negative change in your AC’s performance.

Note that this scenario rarely happens, but it would be unwise to leave it out.

To be on the safe side, make sure you hire an inspector. They know how to check whether your foundation is in good health. This will help to keep your home’s foundation off the list of possible causes of HVAC malfunctions or underperformance in your house.

The main point you need to note is that your home’s air conditioning is dependent on a lot of things including doors, windows, walls, insulation, and floors. If foundation issues deform any of these parts, you will notice it in your AC’s performance sooner or later.

Jim Oursler, one of the co-founders at Granite Foundation Repair, is an engineering graduate from Purdue and has well over ten years in the foundation industry. He is one of the most respected foundation contractors in Dallas and surrounding areas. His company specializes in residential foundation repair, apartment foundation repair, commercial concrete slab and pier-and-beam foundations – and in taking care of their customers. Granite Foundation Repairs has offices in Dallas, Arlington, Plano and Rowlett.