Now it’s getting interesting
I wasn’t thinking that the flow itself as being the mechanism keeping the pipes from freezing rather the flow moving warm water from the hot water tank into both the hot line and the cold line snd hopefully not letting the water in the pipes get down to freezing temperatures.
If it stayed as cold as it was this week I’d figure how to test this in a comparative environment but hopefully by the beginning of next week we go above freezing and stay there fir the season!
Cheers.
That’s a neat way of recirculating. And would certainly keep the hot lines from freezing in cold temps.
Would have to do the same to the cold line I suspect if that were used freezing.
And sadly with the way they have my house plumbed with a few main lines and then tees to respective taps....you’d need to be a water whisperer to figure how to find a specific tap!
Again. All great ideas when building a house but once in all these options have their unique challenges.
If that loop has several joints / fittings as well as the pump it self will cause some "friction" and this friction does heat up the water in some sorts making it less prone to freezing by a couple of degrees. But at some point the outside temperature (of the pipe) will make that water freeze anyway.
So the best way is still the drip method because you are getting that underground water (well or city supply) in the mix that will be at a higher temperature and this higher temperature is what will prevent the pipes from freezing.
The loop would push hot water from the water tank into the cold lines. I’m not certain how much however but the intent of the re circ system is to move the stagnant water in the hot line through the cold line ( back to the hot water tank) thereby refreshing the hot water in the hot line.
So the flow isn’t keeping from freezing but rather the introduction of the hot water into the loop.
Cheers
I hear that. I lived in Northern Canada for 15 years. Cold enough for long enough freezes even fast moving rivers!
I was thinking it was more the introduction of hot water into the lines that would prevent the freezing more than the water flowing.
But I’m starting to I think that if there was any significant anti freeze capability of a water re circ system then the manufacturers of those systems would have mentioned that on their web sites.
Might be over thinking the benefit.
Cheers.
After reading the last 15 or so posts regarding using a recirculating pump to prevent freezing, I am glad this is a forum about home automation, logic, and to an extent computer code, LOL.
A recirculating pump installed on your hot water line, only keeps your hot water line warm, and typically only your hot water main terminating at only one hot water fixture. It does nothing for any of the cold water lines in your house, except for a typical 6 inch portion of your cold water line where it ties into the HWT supply. (Once it ties into the cold water supply of the HWT, typically a few inches away from the HWT, the flow is directly into the tank and then back out, think about it, LOL). The only portion of your cold water line system that a recirc pump keeps warm is the few inches of the cold water supply line that feeds the HWT, between the HWT and where the plumber ties in the recirculating line.
It also does nothing for your hot water line branches to each fixture, other than the one fixture, you are tying in the recirculating line into (usually the farthest one from the tank). And obviously does nothing for your cold water lines.
I recirculating pump is not a strategy to prevent lines from freezing, yes it will prevent about 30% of the piping in your home from freezing, but does nothing for the other 70%.
I agree with you there, keeping the temps in the pipes warm will definitely prevent freezing. Moving water helps, but it is more of prolonging the inevitable. But keep in mind how a hot water recirculation pump works. It pumps stagnant hot water that has cooled off in the hot water line back down the cold water line into the tank. As it does that it refreshes the hot water line with actual hot water. Now I believe my pump cuts off around 90°F, because if it has been running for a bit and the cold water is turned on it is somewhat warm.
Not saying it would be a permanent solution, just keeping the water moving. But in disastrous situations like what Texas is seeing (well for them), really anything to prevent a pipe bursting would be helpful.
You may be correct in some situations, but for my setup you're wrong. I assume you are referring to a separate return line plumbed in for the hot water line? Though, for my system the return line for the stagnant hot water is the cold water line. Therefore, the cold water line from my basement to my 2nd floor will have water flowing through it when the pump is running.
Now, would that really make a difference helping the cold water line? I would think so, and here's why. The thermostat on my return valve shuts off around 90°F. Therefore, if the water in my cold water line is lets just say 40°F, and the hot water line has cooled off to 60°F, then its going to pump that 60°F water down the line until it hits 90°F and the thermostat kicks out.
I have noticed this personally, if the pump was just running for a bit and I turn on the cold water, it is usually warm for 10-20 seconds until the water gets colder.
Though, I do agree, unless you have every sink installed with a recirculation valve, then its not going to recirculate your whole house. Though, if it happens to save a chuck of pipe in the walls from freezing or instead bursts something outside of a wall (like under a sink) it would be most likely less expensive to repair.
Of course, there is an unintended consequence. The water usage is WAY up in Texas (to summer levels). This has further stressed the water treatment facilities (which were experiencing outages also). So a lot of locations are now on boil orders. The joy just keeps on coming.
@JohnRob another engineer!! Congratulations on the patent.
I don’t think it’s reasonable to consider this an adiabatic process. After all it would be adding energy to the system via the pumping action and the warmth in other parts of the house. In actual practice, adding mechanical energy to a system is the foundation for devices like this: Power House - P750 Ice Eater - The Most Trusted Name in the Industry (thepowerhouseinc.com).
MUCH better than copper, in general. Where there are issues it is usually at connection points/joints.
Plastic water lines got a bad rap back in the polybutylene days (which was ALWAYS the wrong material to use - shame on the manufacturers). But current materials, like PEX, have shown to stand up very well over time. It has been used in many countries for many, many years now.
What you have is called an integrated loop system, and is generally only installed on retrofits. It is less than ideal as you will have hot water in your cold water lines. This is dealt with by needing to run the tap for a while to get cold water. Since at most fixtures you don't mind if the cold water tap provides warm water, it doesn't really matter. But this is a very inefficient system, especially when you think of flushing a WC with water that was at least partially warmed by your HWT.
Having said, it is immaterial to what I posted above, a recirculating pump does nothing for the majority of the piping in your home. The test is simple, calculate the entire amount of hot and cold water piping in your home, with no fixtures running turn on your recirculating pump. Calculate the amount of feet of water piping that now has flow going through it due to the recirculating pump. Regardless of your system, this percentage will be under 50%. Therefore a recirculating pump is a poor strategy to deal with freezing pipes.
My father owned a Plumbing and Heating company, it is all I did growing up. Although I am now a high school math teacher, I still have a Red Seal in Plumbing and a Gas-Fitters license in my wallet. There was a time in my life, I installed more of these systems than I care to remember, LOL.
Mechanical?
