Choosing The Right System

Determining the model(s) or size(s) of ETS equipment needed for your application is just slightly different from sizing up conventional heating units.

It is important to accurately determine the size (and quantity) of units needed to satisfy your heating needs. Improper sizing (over or under) may have an adverse effect on system and installation cost as well as efficiency and comfort.

Your local dealer will assist you with this process and is able to more accurately determine which unit is correct for your space. Contact Your Local Dealer Today!

There are three basic steps in determining appropriate heater size:

	Calculate the heating requirement (heat loss rate) for the area you intend to heat.
	Determine the number of off-peak hours available (based on electric rate from your power supplier or your facilities load profile).
	Select the model (unit) that will satisfy the heating requirement based on off-peak hours available.

Step 1: Calculate the Heating Requirement

Several factors impact the heat loss rate (or heat requirement) for an application. These include:

• Size of area to be heated
• Quality of construction - i.e., insulation value of walls, ceilings, windows, doors, etc., (usually referred to as R-Value or U-Value)
• Infiltration rate and/or fresh air requirements
• Indoor room temperature desired to be maintained
• Your local winter weather conditions

There are various energy auditing software programs which dealers use to guide them through the process of determining the heat loss rate.

To most accurately size heating equipment and ensure total comfort even on coldest days of the year, a formal heat loss calculation must be completed. For a rough estimate, short cut methods many times are used.

Contact Your Dealer to have an accurate heat loss calculation conducted for your home!

Step 2: Determining the Number of Off-Peak Hours Available

Contact your local power company to find out how many off-peak hours are available per day and what the times are. If you are a C&I account, your Facility Manager will review the power load profile of your building to determine the number of off-peak hours available during the typical day and what those times are.

Step 3: Selecting the Heater Model that will Satisfy the Heating Requirement Based on the Off-Peak Hours Available

Once the heat requirement has been determined and you know the number and duration of off-peak hours available to you, you can now determine the size of ETS equipment needed to satisfy your needs. Refer to this table for information on the heat loss amount each heater model can satisfy under a sampling of utility off-peak hour strategies.

Simply select the heater model that will satisfy your heating requirements based on the corresponding off-peak hours.

Dealers and distributors may contact Steffes for maximum heating abilities of the heaters under control strategies that may not be listed.

For commercial and industrial (C&I) applications, please also refer to the ThermElect Sizing page.

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