Originally Posted By: John Furr
This post was automatically imported from our archived forum.
First off where do you live? Do you have natural gas service? What are the comparitive costs of your utilities?
I am astounded by people who want to keep older equipment even if that equipment costs them far more than they could be paying with modern efficient heating equipment utilizing cheaper fuels.
Since you are installing ductwork already I would recommend discontinuing the use of electric radiant heating. If you cut it, most electricians wil refuse to patch it. Too many chances of creating a fire. where I live insurance companies will not insure such systems.
35 years is approaching the end of the lifecyle of the system, and if it fails suddenly you can be left without heating and replacing a system under that situation always leads to price gouging.
Depending on your region and the weather I would recommend either a heat pump if your winter conditions do not drop below freezing, and you only have electricty service. Or if you have natural gas or propane you may want to install a high efficiency furnace if the rates are less than the equivalent heating for electric resistance heating.
hey once you have the ducts, it only makes sense.
Just ensure that you have proper heat loss/heat gain calculations done to size the equipment and dont oversize, especially on the AC unit. When you have completed load calculations you can then do an energy cost analysis to determine the least expensive energy source available to you.
I hope you avoid being one of the horror stories I have seen with electric radiant ceilings.
One word about ducts in attics... seal them with mastic based sealer, and insulate to well above the code minimums.... you lose approximately 10% of your capacity to the exterior of the structure. Leaky ducts also can cause the structure to depressurize or pressurize depending on which side of the ductwork the leak is on.
If you must continue and keep your exisitng system, rent a current tester that locates buried wires and carefully plot out the radiant cable in the areas where you wish to locate ductwork penetrations.
Round vents are smaller area than rectangular... so you may be able to cut your penetrations without getting close to the cable..
Never simply cut away... you may never find someone willing to do the repairs or able to find suitable splicing cable.
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John Furr
Residential Efficiency and Training Resources of Ontario