Most people understand that hot air rises; this is a well known factor that presents a problem that your HVAC system needs to overcome to cool or heat your home evenly. This is why many homes that have a less than optimal HVAC system may have a second story that’s hotter than the ground floor. But, this isn’t the only factor, and a close examination of your HVAC system may reveal other causes. In this article, we will examine why this temperature disparity could be occurring in your home and look at some ways to make your home feel more comfortable and save money on your energy bills.

The Air Conditioning System

The average useful lifespan for an air conditioning system is 15-20 years if the equipment has been well maintained. So, it’s inevitable that every homeowner will need to replace their HVAC system at least a few times during the course of their life. When a new HVAC system is installed it will have an optimal efficiency, and every year after that this will be gradually lost. The system can be made more efficient with regular maintenance, but it will still lose some efficiency as the equipment ages.

As the air conditioner gets older and it’s time for a replacement it will be far less effective at cooling your upper story. The HVAC system may be incapable of meeting your demands, and it’s a good idea to get it checked out by a licensed technician to make sure. If you have regular servicing on your HVAC system prior to each cooling or heating season, the technician may have already warned you that your equipment is reaching the end of its useful lifespan.

There are other reasons why your HVAC system may be failing to provide even heating or cooling to different stories in your home. The HVAC system is a complex piece of equipment with many components, and if one of these parts fails, it can affect the efficiency of the entire system. The HVAC system may have been badly installed, or an incorrect load calculation was used, and the fitted system cannot meet the demand. It may simply be the case that the HVAC system needs servicing to get it running at a reasonable level of efficiency.

Ductwork Problems

The further you go from the air conditioner, the more ductwork the treated air needs to pass through to reach its destination. If the ductwork leading up to the second story has leaks or gaps where the air can escape that floor will not receive an ample volume of treated air. Ductwork can develop leaks or cracks over time, or a poor quality installation may be the cause.

All of the joints in your ductwork need to bolted tightly together and sealed with a mastic compound to prevent air leaks. Then the ducts should be insulated to ensure maximum energy efficiency levels. Some section of the ductwork will be hard to examine, but the sections running through the attic or basement should be visible. If you find any obvious leaks or cracks, you can attempt a DIY repair with a mastic sealant. This is likely to be a temporary fix, and if the crack is larger, you will need professional help.

There could be hidden air leaks throughout the ductwork system, and many of these could be located in hidden sections that you cannot reach. If the ductwork is old or the damage is extensive, it’s usually less expensive to replace the ductwork entirely. A licensed HVAC technician will be able to carry out a pressure test on your ductwork to determine the extent of the problem. If the repair is practicable, a liquid sealant mist can be circulated into the ductwork to patch up any minor air leaks without causing major disruption to your home.

Attic Insulation Levels

On a very hot day, you may discover that your attic space is filled with superheated air. If you don’t have a good level of insulation between your attic and you upper floor that heat will radiate into that space, making it feel much hotter. We need good attic insulation all year round; it’s a vital thermal barrier to keep the hot air out in summer and keep it in during the colder winter months. If your attic has inadequate levels of insulation, it will be much harder to keep the temperatures in your home consistent.

Insulation levels are measured using R-values, and a higher rating indicates greater thermal resistance. The ideal insulation R-value for your home can be found on an insulation map on the U.S, Department of Energy website. If you visit your attic, you can attempt to determine the level of insulation that you have there. Here are three quick tips on attic insulation levels.

  • A home in a warmer climate should have 12-14 inches of insulation.
  • A home in a colder climate should have 16-18 inches of insulation.
  • If you can see the joists, you probably need more insulation.

Blocking attic heat is useful, but you also need ways to reduce that heat using methods, such as rafter and soffit ventilation and an attic fan.

If you need to block out more heat, there are new roofing materials available that are designed to reflect heat away from your home. There are even special coatings that you can apply to make your roof heat reflective. If you’re interested in this approach, make sure that your chosen product has an Energy Star rating to ensure that it meets high standards for energy efficiency.

The Treeline

Some multi-storey homes may be surrounded by extensive young tree growth, and this can create a great deal of shade on the exterior surface of your home. In summer, you may find that your ground floor windows are getting plenty of shade, but the upper floors are receiving direct sunlight. Eventually, the trees will grow and provide shade to the upper floors too, but in the interim period, this will create a temperature disparity. This problem can be solved by adding window treatments, such as blackout curtains, heavy drapes or reflective sun shades to the upper floor windows. Keep these closed at the hottest times of the day to block out that unwanted heat.