Balance is a powerful virtue. It makes life stable in a host of different ways, and when you find something out of balance, like your checkbook or your diet, you usually have a problem to correct.
There’s certainly a problem to correct when the temperature inside your home is uneven, and you’ll naturally want to restore your entire house to one uniform, comfortable temperature.
When your indoor temperatures are unbalanced, you’ll notice hot and cold spots in different rooms in the house. This calls for a little more than just adjusting the thermostat. Say you’re feeling chilly in one room. If you raise the overall temperature setting, you may just wind up making a relative in the next room feel uncomfortably hot.
Hot and cold spots in the home can be devilishly frustrating “catch-22” problems.
The culprit in most cases ends up being a problem with your HVAC system’s airflow.
When your system sends too much or too little air into a given room, the result can be a cold or hot spot. This is a fine general explanation, but there are lots of more specific reasons that come into play in your home. Each unbalanced airflow case is unique.
We have tackled this kind of indoor temperature difference problem many times. The professional definition of a temperature imbalance is a difference of more than four degrees between two different rooms in your house.
The following culprits, alone in or in combination, are usually the cause of temperature differences:
- Improperly-sized ducts or boots
- Damaged, leaking, or poorly installed ducts
- Improperly designed or balanced ductwork
- Your HVAC system is overloaded by heating or cooling more space than it’s designed to (i.e. after you’ve built an addition)
How do you fix uneven airflow in your home? Do you need to diagnose the precise source of the problem?
Not always! The easiest fix is one that’s often effective: Just add more airflow.
This means installing a new supply vent and return duct in the room that isn’t getting enough air.
You can solve the reverse problem — a room getting too much air — even more easily: Just add a manual damper that fully or partially blocks off the existing vent.
These symptomatic solutions often solve your uneven temperature problem. What if they don’t? Or what if they make the problem worse?
This is, unfortunately, all too possible. If your HVAC system is sized properly for your home, there might not be a lot of spare capacity available. Adding more airflow to one room might cause shortages in others. If your “solution” to your problem causes even more problems, you could end up chasing your tail.
And what about unbalanced temperatures caused by duct issues deep within your HVAC system? All the damping and vent installation in the world won’t fix that. If the ducts aren’t big enough or the system is poorly designed, it may just be impossible to get air where you want it.
Adding airflow can be an effective solution to uneven indoor temperatures. But it’s no silver bullet. Sometimes it’s ineffective and sometimes, sadly, it can just bring up new HVAC troubles.
So what’s the PROFESSIONAL solution?
Measurement and adjustment.
This is how we fix temperature balance problems permanently and effectively:
1) Calculate air load on a room-by-room basis. In the industry, we call this a “Manual J” load calculation. The goal is to mathematically define each room’s air requirements.
2) Measure vents’ real-world air delivery. Our HVAC professionals use a digital hood to accurately measure the amount of air coming out of a supply vent.
3) Compare room loads. Once we have reliable figures, it’s easy to see which rooms need more air and which are getting too much.
4) Check for air infiltration. Not every hot or cold spot comes down to a problem with your HVAC system. You may have outdoor air penetrating your home, working against the system and causing localized temperature differences. We use a blower door test to determine if your home has air leaks and, if so, to find them.
5) Assess insulation. Another potential source of uneven temperatures beyond the HVAC system is a fault in your home’s insulation. If your insulation is damaged, badly installed, or inadequate, certain rooms could be difficult or impossible to heat and cool properly.
6) Analyze your ductwork. If the data we collect suggests that your HVAC needs to be adjusted to optimize airflow, we will assess your existing ductwork to find out where changes are needed.
As noted in the process above, we always make sure to check external problems — that is, air leakage and insulation issues — to make sure that we get to the real root of the problem. It would be a waste of your time to fiddle with your HVAC system when the real problem lies elsewhere!
This process requires more professional expertise than simply installing a new register or an air damper. The good news about tackling your problem professionally is that your odds of finding an effective solution go way, way up. Instead of fussing around with half measures, you can rest assured that you’re fixing the problem the right way the first time.
Airflow And Home Additions
When you have an addition or expansion put on your home, many contractors will simply run new ducts into your existing HVAC system. If your system has the surplus capacity to handle more space without affecting the job it does in your original home, great!
But all too often, this sort of incautious addition overtaxes your HVAC system and starts creating new hot and cold spots. There are a few different ways to fix this:
- Follow the full professional procedure outlined above. The air load calculations, expanded to address your original home and your addition, will show whether or not your system can handle the space.
- Condition the addition separately with a mini-split heat pump. This solution entails removing any ductwork tying your addition into your main home; that means you’ll return to your pre-addition HVAC performance. Then, you install one or more mini-split heat pumps to heat and cool the addition. Mini-splits are an effective, efficient way to heat single rooms.
- Upgrade your HVAC system. Perhaps the most forward-thinking way to solve a heating or cooling problem with an addition is to install a new HVAC system that’s properly sized to handle the expanded house. You need to use a professional load calculation to determine how big a system you need. There are potential pitfalls in having a system that is either too small or too large.
Although solving uneven indoor temperature problems can be a hassle, never doubt the fact that balance is possible.
Unless you have bigger problems, like gaping holes in your roof, it’s always possible to cool down overheated rooms and warm up chilly ones. Sometimes this requires an expert’s assistance, but some hot and cold spots can be fixed on your own. Whatever solution is right for you, the sooner you find it, the sooner you can enjoy perfect comfort in every room of your home.