FYI: Underfloor heat storage

Efficient system creates a heat reservoir under your building.

What is underfloor heat storage?

Underfloor heat storage systems are installed at the time of construction underneath the concrete slab foundation of your building. This system creates a heat reservoir that heats your home or business across to provide comfort when temperatures drop.

Underfloor heat storage comes in two forms:

  • Electric panels or cables, which are buried 8-12 inches deep below the concrete.
  • Hydronic heat storage, or an in-floor hydronic system, which circulates hot liquid through tubes buried in sand to create the heat reservoir.

Benefits of underfloor heat storage

Nothing beats the feel of warmth under your feet. Heat is evenly distributed across your floor, radiating to reach every corner without drafts or dry air. Underfloor heat storage is also:

  • Clean — Dust is not circulated, meaning the system is clean and quiet.
  • Convenient — No vents means no limits to where you place your furniture
  • Effective — You can heat an entire building, or you can supplement another heat source
  • Efficient — 100% energy efficiency and eligible for some of our off-peak rates

How do they work?

Like all thermal-storage systems, you can think of underfloor heat storage as a kind of “heat battery.”

Underfloor heat storage systems are installed below cement slabs as construction is underway. Because the system is buried in a bed of sand, it creates a heat reservoir beneath your building—this radiates heat evenly from every square foot of your floor, keeping air temperature constant and comfortable.

Sizing is important and will vary according to the length of time your preferred energy rate may manage energy delivery. Work with a qualified contractor to find the right size for your project and the off-peak rate you wish to use.

Rebates are available

Install an underfloor heat storage system system on a qualified discounted off-peak rates and receive a rebate. See details in our program pages below.

Related programs

Residential Business

Deferred Load Rate

Store now, use later—save up to 30% on your heating and cooling costs by switching to our Deferred Load Rate.

Electric heating rebates

Rebates are available for several electric-heating technologies.

Fixed Time of Delivery Rate

Set your energy delivery to off-peak hours to store heating and cooling power for the day—all at one of our lowest prices.

Thermal-storage systems

Add a thermal-storage system to a new building or upgrade an existing system and get up to $75 per kilowatt in rebates.