If you are wondering about what size tankless water heater do i need for my home this is a very necessary thing to know for meeting your demands. Unlike traditional tanks of storage for your tankless water heaters you should have to precisely determine the size and capacity.
As if you choose a small size you will face a shortage of hot water and larger size will lead to expensive installation costs, energy cost as well. In this guide you will learn about everything that you should consider while installing or replacing tankless water heaters. This includes BTU rating, flow rates and practical sizing examples.
Why Proper Tankless Water Heater Sizing Matters
As tankless water heaters are modern systems and they rely on GPM (gallons per minute)and heating capacity. These types of water heaters instantly deliver hot water and do not store water in tanks like traditional systems.
That’s why incorrect tankless water heater sizing leads to:
- Reduce water pressure
- Higher energy bills
- Inconsistent water heaters
- Heavy load on system
So it is very important to determine the correct tankless water heater sizing before installation.
Factors determining tankless water heater size
Here are some factors that you should consider while selecting the size of your tankless water heater.
Flow rate (household water demand)
So the very first step in determining what size tankless water heater I need is calculating how much fixture or amount of water is used daily in your home. It also means that how many members are in family and what are water requirements.
Here a simple guide:
Fixture and average flow rate
- Shower: 2.0-2.5 GPM
- Dishwasher: 1.5-2.0 GPM
- Faucet: 1.0-1.5 GPM
- Washing Machine: 2.0-2.5 GPM
For instance
- 2 Showers(2.5 GPM)
- 1 Faucet ( 1.0 GPM)
So the total is equal to 6 GPM.
Temperature rise
Temperature rise refers to the difference between the temperature of ground water and the desired output water temperature. Like in regions where there is colder climate high temperature is required for heating and in moderate climate regions low temperature is required.
Read More: Understanding Tankless Water Heater GPM.
Electric vs gas power source
As there are two types of system like gas and electric so choosing these also affects performance and sizing.
Electric units have lower capacity and they are normally suitable for small homes.
Gas units provide higher output and they are suitable for larger homes.
So understanding about these is really important especially when you are considering tankless water heaters BTU requirements. Gas models are measured in BTUs.
What are BTU requirements
So when you are considering gas models you have to check the tankless water heater BTU requirements in which your water demand matches with the heating power.
Normal BTU ratings include:
- Small home: 120,000 – 140,000 BTUs
- Medium home: 150,000 – 180,000 BTUs
- Large home: 180,000 – 199,000+ BTUs
That’s why accurate tankless water heater BTU requirements ensure the system optimal performance without any fluctuation in temperature and other things.
Sizing of electric tankless water heaters
Likewise gas systems in sizing a tankless electric water heater you have to focus on kilowatts instead of gas models BTU ratings.
Electric units are best for their installation in:
- Small size homes
- Small apartments
- Point of use systems
The typical sizing of electric tankless water heater is:
- 8–11 kW Single faucet
- 18–24 kW Small apartment
- 27–36 kW Whole house (limited use)
Proper sizing of tankless electric water heaters is essential as they cannot handle the load of high demands like gas models.
What is a tankless water heater size calculator
A tankless water heater size calculator is one of most useful tools for many homeowners.
For determining the right size of tankless water heater you simply input:
- Number of fixtures of daily use
- Flow rate
- Temperature rise
- The calculator will show you the required output size you need for your home.
Nowadays many people rely on this tankless water heater size calculator for ease but still there can be some issues. So it is recommended to consult professionals like MileHi HVAC for advice.
Tankless water heater for 2 bathroom house
Here a some scenario for your better understanding like choosing a tankless water heater for 2 bathroom house
Typical Usage
- 2 showers
- 2 sinks
- Washing machine
So the simultaneous demand:
- Showers: 5 GPM
- Other fixtures: 2-3 GPM
- So the total GPM becomes 7-8.
According to this the recommended size for electric units is 160,000 to 180,000 GPM and for gas units 37-39KWh.
Step by step process for correct sizing
If you are installing or replacing the system with a tankless water heater then follow these steps to ensure accuracy about what size tankless water heater I need.
Make list of all fixtures
Identify everything that needs hot water for daily use.
Calculate flow rate
Add GPM for daily usage.
determine temperature rise
Subtract the ground water temperature from the desired temperature.
Choose the system type
Decide what you need for the electric or gas system.
Select the unit size
Check the flow rate + temperature size to select the size of the unit.
Professional recommendations from MileHi HVAC
So if you are thinking about a tankless water heater and confused about its size then contact our experts at Milehi HVAC. We will help you in choosing the best tankless water heater sizing according to your needs and assures your system optimal performance without any issues.
Final thoughts
Your household’s size, water usage patterns, and climate all influence what size of tankless water heater you need. Calculate your total GPM (gallons per minute) demand depending on the number of fixtures you anticipate using simultaneously in order to choose the appropriate size. Compare the temperature of your incoming water to your target hot water temperature to account for the necessary temperature rise. To guarantee continuous performance, pick a unit that satisfies or slightly beyond these specifications. Professionals like MileHi HVAC can help guarantee precise size, maximum efficiency, and long-term savings if you’re still not convinced. Need expert help? Contact us today for reliable Tankless water heater installation near Denver service and professional installation you can trust.
FAQS
How may a tankless water heater that is too small affect me?
A small unit cannot meet demand, which leads to a weak hot water delivery and temperature fluctuations.
Is it possible to heat a whole house with an electric tankless heater?
Yes, provided that a tankless electric water heater is appropriately sized and that concurrent use is kept to a minimum.
For a tankless water heater, how many BTUs are required?
The size of your house determines this. The typical tankless water heater BTU requirements are between 120,000 and 199,000 BTUs.
Can a home with two bathrooms use a tankless water heater?
Yes, if a tankless water heater is the right size for a home with two bathrooms, it will operate effectively.
Is a tankless water heater size calculator necessary?
An expert evaluation from Milehi HVAC guarantees accuracy, but a tankless water heater size calculator is a fantastic place to start.
