Electric heat tape for water pipe heat protection that includes insulation and thermostatic control.
Freeze protecting water pipes in unheated or semi-conditioned spaces is essential to maintain flow and avoid costly water damage and plumbing repairs. This may be accomplished by maintaining the heat in the space at a minimum temperature such as 45 degrees. With the passage of the 2012 Washington State Energy Code, any pipe runs in unheated spaces need to be insulated to code.
Another option that has long been available is an electrical heat trace cable installed on the exterior of the pipe that maintains a constant temperature above the freezing point. Modern versions of heat cable are now available for installation on the “inside” or “outside" of pipes. Retro-Line® (internal) and Paladin® (external) feature “self-regulating” characteristics which vary energy output from 0.5 to 7 Watts per foot along their length. Unlike conventional heat cables which typically cannot be insulated, Retro-Line® and Paladin® can be fully insulated. In addition to heating each section of pipe independently, Retro-Line® and Paladin® will respond to the pipe water temperature rather than ambient air temperature, so if a pipe is well insulated and the pipe water is used regularly, heat may not be needed until the temperature is well below freezing. These products are compatible with potable water but can also be used with other fluids. This is not an endorsement for these products, but clear examples of what's possible. See Additional Resources below for some others.
Common locations where heating cables are used on plumbing to prevent freezing pipes including water pipes and equipment that runs under porches or through attics, unheated crawl spaces, unheated garages, farms and well pits. Note that water usage patterns can dictate freeze protection system energy use as groundwater or municipal water is often supplied at about 50 to 55 deg F. It must drop by about 20 deg F to reach it's freezing point.
Status:
I don't think this measure would benefit the customers in my service area for the most part. Might be appropriate as a new construction only measure as part of a larger package.
Uncertain savings
Need to be clear what the baseline is - both in terms of energy use and market size - before proceeding.
The best way to protect pipes from freezing is to design their placement to avoid the problem altogether. In those rare instances where pipes might have to be exposed to freezing conditions this looks like the rational approach.
The range of wattage per foot to use this technology is a concern. There are non-energy options to achieve the same goal that make more sense to me.
Baseline Description:
"Typical" Savings: 0%
This is not an energy efficiency measure as much as a measure designed to prevent water damage from plastic or metal pipe that freezes. Energy use can be considerable, amounting to 210 Watts of heat tracing on a 30-foot pipe.
Simple payback, new construction (years): N/A
Simple payback, retrofit (years): N/A
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.
du Alaska, 07/09/2009. Arctic Trace Installation Manual du Alaska
Technical Advisory Group: 2014 Residential Building TAG (#10) TAG Ranking: Average TAG Rating: 1.68 out of 5 TAG Ranking Date: 04/10/2014 TAG Rating Commentary: I don't think this measure would benefit the customers in my service area for the most part. Might be appropriate as a new construction only measure as part of a larger package. Uncertain savings Need to be clear what the baseline is - both in terms of energy use and market size - before proceeding. The best way to protect pipes from freezing is to design their placement to avoid the problem altogether. In those rare instances where pipes might have to be exposed to freezing conditions this looks like the rational approach. The range of wattage per foot to use this technology is a concern. There are non-energy options to achieve the same goal that make more sense to me.