We installed a solar hot water system that has a couple of circulators, one for the collector and one that runs fluid between the drainback tank and the storage tank. Due to the absolutely minimal space allotted by the designer for mechanical equipment (!) the drainback tank and the circulators are in an upstairs closet and the storage tank is downstairs. The circulators are (I believe) Grundfos, about the same as one would use to run infloor heat, small, low flow rate, minimal HP. Everything is piped in copper.
Anyway, apparently there’s too much sound coming from this setup at the moment. I haven’t heard it yet but the installer called to warn me. My experience is that rigid pipe is great at moving pump sounds long distances. For instance, my well pump is a couple hundred feet away (over and down) but I can “hear” it in the house because (I assume) all of the intervening pipe is rigid, whereas I cannot hear the same sound in the shop because (again assuming) the feed to that building is PEX.
Comments appreciated. Will more expensive pumps make less sound? Are there other methods we could try? The installer could move the drainback tank and pumps downstairs but the piping will still be copper and I don’t know if it would do much good.
Replies
What is the model number of the pump? If it is a 15-58 or similar, you ain't hearing the pump, you are hearing air in the water. Moving the pump "might" help.
These pumps are not positive displacement, they need some inlet pressure to work properly.
I'll try to take a look tomorrow and get the model #. Appreciate your input.
Checked today, the circs are both Taco, one is 1/40th HP, one is 1/25th HP. Does that change your opinions any?
Nope. Got a full Model Number?
Edited 10/15/2008 4:36 am ET by rich1
Here we go:
006-BT4-1
007-BF-5
Ok. You got a couple of Taco pumps. Both bronze, so O2 in the water won't hurt them. The 006 doesn't move a lot of water so you really shoudn't hear any thing from that pump. The 007 moves more but is still a quiet pump. Without being there it is hard to guess what the problem is. How big is the piping on the 007?
One thing that can be a problem is how they are mounted. The motor should be horizontal. If it is upright the system pressure needs to be a minimum of 20 psi.
Running them dry is hard on them too.
This is kinda of like a drive by estimate. A WAG is usually way off the mark.
Thanks for the input, there are a couple of good new items in there for me. Piping is 3/4". The installer is coming out to meet me on Monday.
I'm thinking that small HP pumps like you describe should make only minimal noise ... shouldn't really hear the pump running at all. I've often had to feel the pump to make sure it's running as they tend to be that quiet. Assuming the pump was primed right and is actually pumping water, you should be OK.
The other poster illuded to noise from air in the water ... check to see if it is actually the pump or air ... should be able to tell if it is air or not by the sounds.
Dave, Sometimes it takes only the slightest amount of stress or tension on the copper piping system to set up a vibration that can be heard a long way from the pump.
It's often not the pump itself you are hearing but the copper pipes vibrating enough to make noise.
I would patch in a section of Pex if you can't find anything else wrong. That will usually totally eliminate any noise from a pumping system.
I wondered about putting in some PEX. Possible issue is that water temps are very high. More later, I am going up there after breakfast.
How high are the temps? Maybe that's why they used copper?
With normal water pipes in the wall, you can hear the pipes when they are touching any part of the building. Bored holes in studs that are too small for sound isolation is common. Clamping pipes directly to wood or drywall creates a soundboard.
Wraping pipes with carpet padding, then clamping is an economical way of installation.
Pipes thru framing are run thru rattle plugs. These help some, not always enough.
Could you give us some more info about the system.....brand, ease of installation, personal opinion?
I'm sure many of us are thinking of adding solar, and would love some trusted experience....
It's really just straightforward plumbing, nothing complicated about it at all. I'm sure I'll add the same to my house eventually, it could probably be done in a couple of weekends.