by Norman Aceron Garcia
Insulating water pipes can conserve energy by reducing heat loss through the piping. Pipe insulation will minimize the formation of condensation on pipe surfaces that can lead to mould and moisture damage. Insulating pipes can prevent the pipes from freezing and breaking during the winter, which can cause significant damage in the walls, and consequently, lead to considerable repair bills. Studies have shown that heat losses in un-insulated hot water pipes can range from 16 to 23 per cent, depending on the climate zone. Installing 19 mm (3/4-inch) pipe insulation can slash overall annual water heating energy use by four to five per cent.
In cold climates like Manitoba, locating water pipes close to exterior walls and in unconditioned (unheated) spaces such attics, crawlspaces and basements should be avoided. However, if this is not possible due to existing site conditions, the water pipes should be insulated. For additional pipe protection and energy efficiency, any cavity between the pipes and the exterior wall should be sufficiently air-sealed and insulated.
If the house is heated using a hydronic (steam or hot water) heating system, heat losses can be decreased by as much as 90 per cent by insulating the steam distribution and return pipes. It is also advantageous to align plumbing fixtures with the interior walls.
There are several types of pipe insulation: tubular pipe sleeves, spiral insulation wrap, and fiberglass batting that can be taped around the pipes. As long as the pipe insulation is properly installed, any of these three types can be effective in reducing wasted energy in water heating.
The most common pipe insulation is the tubular pipe sleeve type, which are made from flexible closed-cell polyethylene or neoprene foam and usually come pre-cut with a lengthwise seam for effortless installation. Some tubular pipe sleeves come with adhesive tapes already installed on both sides of the slit. The adhesive tapes can be simply peeled off the plastic coverings and be pressed together. There are several diameters of sleeves available in most hardware stores to accommodate different pipe sizes. It is important to determine the pipe diameter before buying the sleeves because the sleeve’s inside diameter should match the water pipe’s outside to ensure a tight fit.
The following are the steps in installing tubular foam sleeve pipe insulation:
- Cut the sleeve to the desired length, then wrap it around the pipe with the slit facing down and no gaps between the sleeves. For pipe bends, form a mitered corner to match the angle of the pipe length.
- Remove the adhesive strips, then press the edges together.
- Apply acrylic or aluminum foil tape over the seams and joints to increase durability.
- Put an appropriate clamp to secure the insulation to the pipe every 600 mm.
- Put caulk or foam to seal any pipe penetrations in walls, floors, ceilings or framing.
Spiral insulation wraps are usually made of fiberglass, foil, or polyethylene foam. This type of insulation is simply installed by unrolling it and wrapping it around the hot and cold water pipes. Another type is fiberglass insulation that typically comes with a vapour barrier that is wrapped around the pipes after the fiberglass insulation is installed.
Placing hot and cold water pipes close to exterior walls should be avoided. If they must be installed in exterior walls, the pipes must be insulated with sufficient cavity insulation behind the pipes. Air-sealing wall cavities will help avoid cold air from flowing around the pipes that could lead to excessive condensation and moisture problems. Insulating hot and cold water supply pipes minimizes the house’s carbon footprint by reducing unnecessary heat losses in the plumbing system.
Norman Aceron Garcia, P.Eng. is an accredited professional in Leadership in Energy and Environmental Design specializing in Building Design + Construction. In 2015, Norman founded Mr. Peg Property Inspections, a social enterprise that advocates green building design and climate change adaptation strategies.