If your HVAC system is on its last legs or damaged beyond repair, it makes sense to replace it. In addition to using more energy than usual, an old, malfunctioning HVAC system can pose safety hazards.
For instance, if your system has a cracked heat exchanger, the poisonous gases that get burned off, including carbon monoxide, sulfur dioxide, and nitrous oxide, could leak into your home, causing a variety of minor and serious health issues.
One of the most important things to consider when buying a new heating and cooling system is its size. You need to choose the right size system for your home.
An undersized HVAC system will have to work harder and longer to heat or cool your home, whereas an oversized unit will cool and heat your home faster, but you could end up with cold and hot spots throughout your home.
Follow the below steps to determine the size of the HVAC system you need according to Lafayette repair experts, Connolly HVAC.
Step 1: Calculate the BTUs needed to cool and heat your home
British Thermal Units (or BTUs)are a unit of heat. A BTU is the amount of heat required to raise a pound of water temperature by one degree F.
When you’re considering what size HVAC unit to get, it’s important to accurately determine the BTUs required to cool and heat your home.
If your BTU level is lower than the recommended one, your HVAC system will run longer to achieve your desired comfort level. With a higher BTU rating, an HVAC system will cool and heat quickly and cycle on and off. The compressor will be overworked and could eventually break down.
Manual J calculation
To determine the right BTUs for your home, have a professional perform a Manual J load calculation.
A Manual J calculation for your home factors in the distinct characteristics of your home, such as
➢ Position of your walls
➢ Square footage
➢ Building materials
➢ Number and style of windows
➢ Quality and amount of insulation
➢ Number of residents
➢The orientation of your home
➢ Number of heat-generating appliances
➢ Natural shade and sunlight
➢ Climate zone
Many providers offer a free energy audit which includes a Manual J load calculation report. You can also hire an HVAC dealer or energy auditor to perform a Manual J load calculation.
Step 2: Determine the square footage
You can find the square footage of your home on several documents such as appraisal documents, listings, and your home’s lease papers. If you cannot find these documents, calculate your home’s square footage yourself.
First, to calculate the square footage, measure the length and width of every room and multiply them together. Then, add the square footage of every room to get the total square footage.
Step 3: Calculate the necessary BTU output
To calculate the necessary BTU output, you first need to refer to the U.S. climate zone map to determine your climate zone. Homes in Zone-1 require 30-35 BTUs per square foot, homes in Zone-2 require 35-40 BTUs per square foot., homes in Zone-3 require 40-45 BTUs per square foot, homes in Zone-4 require 45-50 BTUs per square foot, and homes in Zone-5 require 50-60 BTUs per square foot.
So if you are in Zone-3, the BTUs required to heat your home will be the square footage of your home multiplied by the range of BTUs for your zone.
Step 4: Choosing an HVAC system based on your calculation
Now that you have calculated the total BTUs required to heat your home, start evaluating your options. When considering an HVAC system, check its efficiency. If an HVAC system is 80 percent efficient and has a BTU input of 80,000 units, it will produce 64,000 BTUs. If your home needs 80,000 BTUs, look for an HVAC system with an input of at least 100,000 BTUs.
If your retailer does not have an HVAC system with the same input you need, go with a bigger unit. If, for example, you need 50,000 BTUs, but your dealer has 40,000 BTU units and 60,000 BTU units, opt for the system with an input of 60,000 BTUs. A bigger system will ensure that your heating and cooling needs are met on cooler and hotter days.
Do not buy too big of a unit. Your unit’s input should not exceed 15 percent over the BTUs you need for cooling and 40 percent over the BTUs you need for heating.
Need HVAC repair services in Lafayette? Look no further than Connolly Heating and Air Conditioning. Whether your HVAC system is not cooling/heating enough or making unusual noises, we have got you covered. To schedule a maintenance visit, call (925) 288-1408.