That is right, if you live anywhere in the northern section of the United States you may have antifreeze in your house. Recently we have had some very cold conditions where the temperature has dropped below freezing. Freezing temperatures of below zero degrees can pose a risk for freezing and burst pipes.
Many of us think of winterizing our homes and think about shutting off exterior faucets and removing garden hoses, but what about your heating system? Many of the newer homes in our area rely on a Hydro or Hydro/Air heating system. This means that the source of heat is provided from hot water. In a hydro system the water is heated by a boiler and piped through radiators or baseboards. The hydro/air system works in a similar way except the water is routed through a coil in an air handler in the basement or attic. Now you may ask, “How can a hot water pipe freeze?”
Believe it or not hot water pipes tend to burst before cold water pipes. You may remember this from science class. The rate of heat loss is faster when hot water pipes are super cooled. This will cause the water to freeze solid quickly in hot water pipes and create blockages that trap water. As the water freezes it expands. The copper pipes that most of us have in our homes have will crack and split under the pressure of the expanding ice. Ouch!
Where does the Antifreeze come into play?
Pipes are the most vulnerable in unfinished areas or in exterior walls where they can be exposed to sub-zero temperatures. Where do we place our heating equipment? Usually they are placed in unfinished areas (basements, attics) and along outside walls. Heating systems that have pipes that run through these areas should be protected with insulation and the addition of an antifreeze additive. The antifreeze is not the kind that you get at the automotive store, as it is poisonous. It needs to be a food grade antifreeze containing glycol. Contacting a qualified heating specialist is the way to go. The antifreeze is added in a process that removes some of the water and replaces it with antifreeze. The heating system needs to have the right ratio of antifreeze and water. The antifreeze typically last 3-5 years before it starts to lose its effectiveness. Having it checked during regular servicing of the heating system will inform you of the condition of the mixture.
The homes that are most at risk of vulnerable heating systems have pipes in unfinished areas or homes that are unoccupied during the cold months. Air handlers in attics can be exposed to severe temperature changes, although most ducts in a hydro/air system have insulation. The air handler and heating coil tend to lack insulation. The heating coils are designed to release heat efficiently and this can make it a weak spot for freezing and bursts. It usually starts with a lack of heat (frozen pipes) and then is followed by leaking pipes (thawed).
The moral of the story is to have your heating system serviced regularly by a qualified contractor. Heed their advice and try not to be “penny wise and a pound foolish”. There are many times that these issues can be avoided if the steps are taken in advance.
Jason Horn is an ASHI Certified home inspector in Newtown, CT and one of the lead inspectors at Pondview Inspections, LLC., a home inspection firm with offices in Newtown and Stamford that services most of Fairfield county and Western CT. If you have any home inspection related questions feel free to call him at (203)304-9140
The answer about freezing hot water pipes was paraphrased from “The Flying Circus of Physics with Answers by Jearl Walker, published by John Wiley and Sons, 1977”
More information can be found at http://contractormag.com/hydronics/cm_column_113 “Why add antifreeze to hydronic systems?”