Why do people wrap insulation on their sprinkler system parts?

[Dan Friedrichs]

When people have their sprinkler systems winterized, they often wrap the outdoor valves and regulator with insulation. In fact, home stores even sell little insulated "bags" to zip over your sprinkler regulators. Why do they do this? Clearly, without warmer water flowing through the components, these outdoor parts will eventually reach the same temperature as the outdoors. Insulation is of no value. Am I wrong?

(Side note: I also see that they sell little styrofoam "hats" to strap on to your outdoor spigots. I guess I believe these have slightly more usefulness, as the exterior of your house may be slightly warmer than the outdoors, meaning that these sytrofoam thingies may succeed in keeping the spigot warmer than the outdoors. These still seem of pretty dubious value, though....)

[Mike Henderson]

My guess is that the ground is warmer than the air so that the insulated bag keeps the pipes slightly warmer than the air. I know that where I grew up in the south, people used to cover their cold sensitive plants with sheets (or whatever) when they knew it was going to be a cold night. The sheet trapped the warm air rising from the ground (the ground was warmer than the air) and saved the plant from cold damage. It certainly worked because uncovered plants would be cold burned while the covered plants were fine.

Mike

[David G Baker]

If there is a wind the wind chill can drop the temp considerably. In Michigan we drain our sprinkler systems and blow out the lines with compressed air. No water, no frozen pipes or fittings.

[Rich Engelhardt]

Side note: I also see that they sell little styrofoam "hats" to strap on to your outdoor spigots. I guess I believe these have slightly more usefulness, as the exterior of your house may be slightly warmer than the outdoors, meaning that these sytrofoam thingies may succeed in keeping the spigot warmer than the outdoors. These still seem of pretty dubious value, though
Copper pipe conducts both heat and cold.
W/the "little hats" on the spigot, the warmth of the interior gets transferred to the spigot.
W/out the "little hat", the cold of the outside is transferred into the interior.

They actually work extremely well - as we found out the hard way...

Spigots don't have to freeze solid for damage to occur to the seal(s). Even outdoor spigots - the long ones w/the valve located inside - can be damaged by exteme cold long before a threat of bursting happens.

[Dan Hintz]

Rich has it...

Also, wind chill only affects animals (i.e., things that perspire). If it's 20 degrees outside and they say it's a windchill of -10, inanimate objects only see 20... the person sweating while shoveling their driveway is seeing/feeling those nasty -10 temps as their sweat evaporates.

[John McClanahan]

It gives you a warm feeling knowing you are trying to keep it safe. It gives them something to sell to you. How well it works is optional.:D

John

[Dan Friedrichs]

I guess I'm thinking about the houses I see where people have taken a bat of fiberglass insulation, wrapped it around their sprinkler system regulators, then covered that with a plastic trash bag wrapped in duct tape. I bet 1 out of 10 houses I see (in the Denver area) has done this. Apparently for no reason. I wonder where people got the idea to do this....

[Dan Hintz]

Dan,

If the regulator's water supply is not within a few inches of the warm inside, the wrap will do nothing if it stays below freezing long enough (a day or so, probably sooner). As Rich says, though, enough residual heat passes from the warm pipe inside to the water just outside in the tap... this is fine if you dip into the 20s, but those that have nasty hard freezes (teens and below), that's not going to help them much as the differential in temp is just too great. Personally, I use the taps that shut off inside the house, but to play it safe I have a butterfly valve on the line leading to the tap and leave the tap open all winter. Any residual water in the tap should drain to the point it's inside the house, and should a deep freeze somehow reach that far and burst the few inches of pipe inside, the butterfly prevents any waterfalls.

[ray hampton]

I let my outside faucet drip at night during the colder period and it would freeze up every time but this winter I never bother to set it to drip and it never froze up not even one time, maybe it never got cold enough 5 degrees below zero if I recall

[Dan Hintz]

For really cold areas, dripping is not enough... you need the stream to be fast enough that the new heat the fresh water is bringing in outweighs the heat loss to the environment. You might get away with a slow drip at just below the freezing point, but at some point you need to step up the flow. It's wasteful, but less cleanup ;)

[Jim Rimmer]

[QUOTE= (Side note: I also see that they sell little styrofoam "hats" to strap on to your outdoor spigots. I guess I believe these have slightly more usefulness, as the exterior of your house may be slightly warmer than the outdoors, meaning that these sytrofoam thingies may succeed in keeping the spigot warmer than the outdoors. These still seem of pretty dubious value, though....)[/QUOTE]

I live in the Houston area and a hard freeze here is below 32 degrees for 3 or 4 hours. I use the little "hats" because LOML thinks they help. ;) They are cheap, easy to install, and a lot less trouble than trying to talk her out of the idea. And, as mentioned in other posts, they may help some.

[David G Baker]

When I lived in Sacramento CA my outdoor faucets would freeze and split, my sprinkler heads would freeze and the PVC supply lines would split due to not being buried deep enough. Had to replace the whole system. I learned to drain the system in the Fall. Had no idea that it froze in California.
To keep out side plumbing from freezing a pencil sized stream of water is recommended.

[Scott Donley]

Rich has it...

Also, wind chill only affects animals (i.e., things that perspire). Wind chill will take a warmer object down to air temp faster then no wind just not below air temp. There is a reason truckers cover their radiators in the cold.

[Dan Hintz]

Wind chill will take a warmer object down to air temp faster then no wind just not below air temp.
Obviously... else there wouldn't be any reason for fans on heatsinks. The point being wind will not chill a non-evaporating item lower than ambient temp.

[Scott Donley]

I guess I took "only affects " as to what you were saying.

[Lee Schierer]

Wind chill will take a warmer object down to air temp faster then no wind just not below air temp. There is a reason truckers cover their radiators in the cold.

Maybe truck radiator covers are made by the same folks that sell styrofoam hats for faucets and sprinklers!!!!:eek: The covers probably allow the engine to heat up faster on cold days and keep the operating temp u so the driver has heat in the cab. Moving air will move heat away from the radiator, but it will not lower the temp below ambient without evaporation.

[Scott Donley]

Moving air will move heat away from the radiator, but it will not lower the temp below ambient without evaporation.That's what I said ! And yes, truckers do it for more cab heat and improved mileage.

[Jim Koepke]

Here in Washington, and I am sure other places, our spigots that are not located on the house have drain valves that empty the riser when the valve is turned off. The bottom of the riser is about 18" or more below grade. I shut off the water to the field spigots during the coldest months and only turn them on to water in the greenhouse.

jtk