• Share:
How Hydronic Radiant Floor Heating Works

If you want to add an addition but your furnace can't handle the additional load, think about installing hydronic radiant floor heating. This will make your addition a warm and cozy without upgrading your furnace.

By the DIY experts of The Family Handyman Magazine

How hydronic radiant floor heating works

Unlike forced-air heating, which works by blowing warm air through large ducts, a hydronic system uses a dedicated water heater or a boiler (or even your existing water heater) as a heat source. A circulating pump moves the hot water through the PEX tubing and back to the heater. Because there can be no joints in the PEX tubing in the floor, uncut lengths of tubing snake through the floor, starting and ending at a manifold. The manifold balances the water in individual loops (lengths of tubing) and vents the system. The water returns to the bottom of the water heater near the drain about 10 degrees cooler than when it left.

What to look for in a hydronic radiant floor heating system

For truly even heat, choose a system that circulates hot water through code-approved plastic tubing (like PEX) that's embedded in a layer of material and covered by ceramic tile flooring. The material can be light-weight concrete, Gypcrete or dry-tamped mortar. This cement-like layer, combined with the tile, makes up a great mass that stores the heat for a long time and continues to radiate it even when the water's not circulating. This constant warmth can greatly increase the comfort of a room, especially in cold climates.

The cost per square foot for a hydronic system will depend on where you live and the size of the job. With a 300-sq.-ft. addition, expect to pay about over $1,500 to have the actual system installed (including water heater, tubing, pump and manifold). Then there's the cost of embedding the tubing. For a fairly small job, the most economical choice is to hire a tile professional to embed the tubing in dry-tamped mortar. That should cost less than $4.00 per sq. ft. Then add the cost of the finished floor. Tile is the best choice.

The cost of a hydronic system for an addition may be about the same as the cost of another furnace (vs. replacing). However, your operating costs will be lower for the hydronic system, the water heater won't take up as much space as a furnace and ductwork, and you'll probably be more comfortable. To find more information or a hydronics specialist, search “hydronic radiant floor heat” on the web.

Back to Top

Comments from DIY Community Members

No comments on the article have been posted yet. Be the first to add your comment!

You will be required to log in or create an account to post a comment.

closeX

Add Your Comment

How Hydronic Radiant Floor Heating Works

Please add your comment
closeX

Log in to My Account

Log in to enjoy membership benefits from The Family Handyman.

  • Forgot your password?
Don’t have an account yet?

Sign up today for FREE and become part of The Family Handyman community of DIYers.

Member benefits:

  • Get a FREE Traditional Bookcase Project Plan
  • Sign up for FREE DIY newsletters
  • Save projects to your project binder
  • Ask and answer questions in our DIY Forums
  • Share comments on DIY Projects and more!
Join Us Today
closeX

Report Abuse

Subject
Reasons for reporting post

Free OnSite Newsletter

Get timely DIY projects for your home and yard, plus a dream project for your wish list!

Follow Us