Commercial Air Conditioning, Commercial HVAC
Sizing HVAC Systems: Why Bigger Is Not Always Better
This is an update to one of our most popular and helpful blog posts. Here’s the original: New York HVAC Systems: 8 Reasons Bigger Is Not Always Better
One of the worst mistakes you can make when purchasing new HVAC equipment is choosing a unit that’s the wrong size for the space. Especially if the old unit was not providing adequate heating or air cooling, you may be tempted to go with a more powerful unit thinking it will provide more comfortable conditions.
It won’t. When it comes to sizing HVAC systems, especially air conditioners, bigger is not necessarily better. What you want is a unit with exactly the right capacity and system design to meet the needs of the space.
8 reasons to avoid over-sizing HVAC systems
Here are 8 reasons why over-sizing HVAC systems is the wrong choice for your heating and air conditioning needs:
1. The unit cycles on and off frequently.
This is called short cycling, and it’s a common symptom of an oversized furnace or air conditioner. It means your system is working much harder, using more fuel, and providing less comfortable conditions. Properly sizing HVAC systems solves this problem.
2. More breakdowns.
With the wrong HVAC sizing, your unit turns on and off so many times throughout the day that it creates a lot of wear and tear on the equipment’s parts. Any good NYC HVAC service company will tell you that as a result, you’ll have parts failing sooner than expected and increased commercial air conditioning repair or furnace repair bills. Not to mention the inconvenience and possible business interruption due to a broken heating or air conditioning system.
3. Reduced equipment life span.
All that cycling is hard on your HVAC system. If you’ve purchased a unit with an expected life span of 15 to 20 years, that unit may fail in as little as 10 years. That’s an important reason why correctly sizing HVAC systems is critical.
4. Higher utility bills.
Incorrectly sizing HVAC systems wastes energy since the equipment uses the most energy when it starts up. Because it’s starting up more times throughout the day, and has a higher capacity to begin with, you will see a spike in your energy usage.
5. Inconsistent temperatures.
The short cycling creates drafty, inconsistent heating and cooling, and you could also experience hot and cold zones throughout your space.
6. Humidity problems and poor indoor air quality.
Here’s another reason correctly sizing HVAC systems is essential. Air conditioners that are oversized don’t run long enough to remove the moisture from the air. This results in too much humidity, which can cause a host of problems ranging from furniture and computer damage to the growth and spread of bacteria, viruses and dangerous mold.
7. Noisy conditions.
That powerful unit cycling on and off all day at full blast makes a lot of noise that can interrupt your business. If you’re running a restaurant, retail location or health facility, it can even drive away customers.
8. Higher cost to purchase, operate and maintain.
Why would you pay more for something that’s going to cost you more to use and provide less comfortable conditions? This is a case where you don’t necessarily get what you pay for. Shelling out more for a higher capacity unit doesn’t get you more comfort. Properly sizing your HVAC systems gives you exactly what you need.
Sometimes less is more when it comes to sizing HVAC systems
In some cases, you may actually need a unit with a smaller capacity than you had previously. That’s because many buildings in NYC have HVAC equipment that was installed by a builder without adequate HVAC expertise. Sometimes builders make the same mistake as home and business owners, and choose a larger unit than is required. Also, when buildings are renovated there are often design and energy efficiency improvements made that decrease the capacity required for heating and cooling.
How the pros determine the correct HVAC sizing for your needs
It takes experience and the right tools to accurately determine the correct capacity for your space. To calculate the correct sizing for HVAC systems, certified commercial HVAC companies will perform a Manual J load analysis.
This service takes many factors into account, including the square footage of your space, design elements, energy-efficiency features, building occupancy patterns and how the space is used. Most quality HVAC service providers use a software tool to do this calculation.
Don’t make the rookie mistake of buying heating or cooling equipment with a higher capacity than you need. If you’re being advised to do so by an installer, get a second opinion before you waste your money.
Are you getting bad advice about HVAC sizing?
If you’re doubtful about the advice you’re getting from your current HVAC service provider, you may be thinking about switching but worried about terminating the relationship. There’s no good reason to stay with a provider that’s no longer serving your needs correctly. To learn more about how to make a smooth transition, take a look at our helpful guide to Contract Confidence: Transitioning to a New HVAC Service Provider.
