Swing check valve vs spring check valve for Gravity Fed Hot Water Recirc system

[John Gayewski]

Im not exactly following your point about Sept to May but in any case I guess what I'm saying is I'm not sure I really care about having some pumped system on the recirc. If it hadn't been for someone mentioning that it's not code and has bacteria issues potentially I wouldn't have even thought along those lines.

Its cold during those months. The heat for your house is running less becuse your water heater and recirculation line are giving the house heat.

 

[Jeff H Young]

personal choice I wouldnt know how to figure to the bottom penny which is cheaper or by how much I dont project out the future cost of water or gas last year was crazy this year expecting gas to be a fraction of last winter . Id say eliminate it because you have no interest in recirc and whatever the costs are probebly are minimal anyway. Id be interested if you do indepth reasearch to hear your numbers im sure it will take hours maybe contact some government agency for free assistance

 

[Sponsor]

 

[Tuttles Revenge]

Unless a recirc system is very well insulated, they are radiators. In some instances you could calculate that as part of your heating.. same as why highrises generally don't or at least didn't turn off the lights. They calculate that as part of the heating. In one home that we worked on the uninsulated recirc lines ran behind the thermostat and prevented the heat from working properly.

Likely the gravity system requires the line to be unheated in order to create the heat loss on the return side.

Personally I don't sell recirc systems for their energy values.. I only sell them on their convenience.

 

[Hogan]

Unless a recirc system is very well insulated, they are radiators. In some instances you could calculate that as part of your heating.. same as why highrises generally don't or at least didn't turn off the lights. They calculate that as part of the heating. In one home that we worked on the uninsulated recirc lines ran behind the thermostat and prevented the heat from working properly.

Likely the gravity system requires the line to be unheated in order to create the heat loss on the return side.

Personally I don't sell recirc systems for their energy values.. I only sell them on their convenience.

Interesting and sort of backs my gut feel on this. My Pipes are for sure uninsulated copper and behind the drywall of course. I like your analogy to a radiator. That's what I was trying to say. Why pump a bunch of 120 degree water round and round for hours per day into uninsulated copper pipes behind drywall, all to avoid the "horrors" of having to wait 30 seconds for hot. I also agree that for a gravity passive system to work it needs to have cooling. I guess I'm not gonna get too fussed about this and will see if the check valve succeeds in stopping a cold backflow up that line. I don't think I want to spend more money to have some radiator pumping around hot water for hours per day.

 

[Jeff H Young]

Interesting and sort of backs my gut feel on this. My Pipes are for sure uninsulated copper and behind the drywall of course. I like your analogy to a radiator. That's what I was trying to say. Why pump a bunch of 120 degree water round and round for hours per day into uninsulated copper pipes behind drywall, all to avoid the "horrors" of having to wait 30 seconds for hot. I also agree that for a gravity passive system to work it needs to have cooling. I guess I'm not gonna get too fussed about this and will see if the check valve succeeds in stopping a cold backflow up that line. I don't think I want to spend more money to have some radiator pumping around hot water for hours per day.

simple as that dont do it then ! I dont sell recircs i only recomend them to those that want them . but i cant come close to estimating the true cost of a circ system you could pay some brainiac to figure it out and maybe he would come close? like having airconditioning if you are never hot and dont want to spend the money dont put ac in your house. Ive worked in houses both new and and remodel where somethings seem a luxurious waste of money but its thier money and things have value to some and not others

 

[Hogan]

In thi

simple as that dont do it then ! I dont sell recircs i only recomend them to those that want them . but i cant come close to estimating the true cost of a circ system you could pay some brainiac to figure it out and maybe he would come close? like having airconditioning if you are never hot and dont want to spend the money dont put ac in your house. Ive worked in houses both new and and remodel where somethings seem a luxurious waste of money but its thier money and things have value to some and not others

Agree

In this case I already have the gravity lines so whats done is done. My only worry was reading the post above about these lines becoming a "dead leg" and breeding bacteria etc and needing to be actively circulated. I guess to my knowledge we've not had an issue in 20yrs with them so just leave well enough alone, put in the check valve and see if it works to hold back the cold backwards flow, and if it doesn't then have the plumber change the layout so the recirc line attaches to the bottom of the tank

 

[Jeff H Young]

there is an easy way to eliminate a dead leg , by capping it off at ends as short as you can

 

[Hogan]

there is an easy way to eliminate a dead leg , by capping it off at ends as short as you can

I honestly don't know how to find the recirc lines upstairs. They are probably behind drywall. So I can't cap them off.