Insulating Water Pipes – Suggestions & Tips #167

Insulating water pipes seems straight forward enough, but many homeowners don’t do it. In part, that’s because it’s not understood why it should be done in the first place, how it should be done and what water pipes should be insulated. Here are some things to consider before starting your water pipe insulation project:

Cold Water Supply Pipes – reasons to consider insulating cold water supply lines:

• If the basement / crawlspace is a conditioned space (e.g. heated and insulated), the uninsulated cold water pipes can absorb heat from that space. That is, the cold water pipes are colder than the air temperature in the basement / crawlspace. This is true when the water is turned off (the pipes don’t stay cold as long) or when the water is running.

• If the basement / crawlspace is unconditioned (e.g. not heated / insulated), then the uninsulated pipes run the risk of freezing (just as hot water pipes would). So, insulation can help to reduce the chance of pipes freezing or worse yet bursting and leaking into the space.

• Lastly, condensation occurs on cold surfaces when met by the warmer air. In summer for example, cold water pipes will condense and get water dripping from them if left uninsulated.

Hot Water Supply Pipes – reasons to consider insulating hot water supply lines. This is not for radiant hot water heating pipes (see below):

• There can be heat loss depending on the length of pipe and volume / speed water is called upon. Some estimates suggest that by insulating your hot water pipes you can prevent a 1°C–2°C heat loss in water temperature. As a result, saving you energy if you lower the temperature setting at your water tank.

• If the hot water pipes are exposed to very cold air in an unconditioned space (e.g. unheated crawlspace) they should be insulated regardless to prevent freezing and a pipe burst. Further, it reduces energy costs.

• If you want water to arrive at a faucet or the shower quicker / hotter, shortening the length of the run from that water heater can help or if you install a recirculating pump (require additional plumbing). Another alternative is to relocate the water heater to a location that is closer to where it’s being used. You could also install an on demand / tankless water heater. Sometimes multiple tankless units can make sense when installed close to its place of use and depending on your demand for hot water.

• To help prevent heat loss, insulate at least the first two metres (2M) of the hot water pipe and one metre (1M) of the cold water pipe leading to / from your water tank. NOTE: If your water heater has a draft hood connecting the flue pipe to the chimney, ensure the distance to combustibles is sufficient for safety purposes and don’t install insulation / pipe wrap within fifteen centimeters (15cm) of this (or as recommended by the water heater manufacturer / licensed heating contractor).

Radiant Hot Water Heating Pipes – generally, this refers to hot water pipes for radiant heating e.g. from a boiler to: a radiator or where encased, for example, in concrete and or floor panels to give off their heat for in-floor radiant heating. This is not for water supply lines (see above).

Take for example the situation we often come across in a basement. There are plenty of radiant hot water heating pipes coming from the boiler, however they are uninsulated. They certainly give off heat that can heat this space. So, why insulate and make the basement or first floor cold?

Ideally, you want to insulate these pipes to control and get the heat directly to where the heat is needed / intended. Often, they do not install radiators in the basement, so leaving the pipes uninsulated heated the space…but inefficiently. In addition, these basements may not have their exterior walls insulated, so there’s enough energy loss happening for everyone 🙂 As a result, we would recommend:

• Insulating your radiant hot heating pipes.
• Add radiators if / where needed in your basement / conditioned space.
• Insulate your basement / crawlspace walls with vapour barriers so that condensation cannot form.

In addition, since your boiler will be creating less hot water, there will be less wear & tear on it. Your boiler typically works on a closed loop system with recirculating pump used to cycle the hot water to the radiators / in-floor heating panels and back for re-heating. As the boiler will be working less, so will you circulating pump.

Tips for Installing Pipe Wrap Insulation

• Use preformed “T’s” and “90⁰ Elbows” for best performance and ease of installation where possible.
• Ensure insulation is self-sealing or sealed manually to prevent heat loss and or condensation from forming.
• Used closed cell foam on cold water lines to prevent water absorption into the foam from any condensation.
• Radiant hot water heating pipes commonly use molded fiberglass with a paper-free jacket. Installation is similar, but not identical to foam. For safety, refer to the owner’s manual / installation specifications for the boiler and or contact a licensed heating contractor for distances to combustible materials for any pipe insulation, for example, to the boiler, chimney, draft hood, etc.
• R-Values, ball park estimates: (1) foam style insulation for hot / cold water pipes varies from about R1.5 to R2.5. (2) molded fiberglass insulation for radiant hot water heating pipes R5 to R6 at 1” thickness.

Perhaps one of the best reasons for insulating pipes is that it does not cost very much to do so, making improvements in heat loss, energy costs, comfort / convenience and water conservation more viable.