Overall piping length in swh systems - Page 3

jeff5may · 11-21-15, 09:56 PM

This question reminds me of a question rookie communications techs asked me about how much equipment they should stock their trucks with to cover daily job needs. You know, because it costs so much gas to drive all that extra stuff around.

My question in return was this: If you want to spend lots of time on the road, don't load your truck with anything extra. That way, you can drive to your heart's content finding something to complete your jobs. If you want to get promoted, load your truck with all the stuff the whole team might ever need. Then we can trade with each other when I have something you need or vice versa.

Much like your situation regarding plumbing, you never really know exactly how much piping or what specific fittings will be needed without some sort of site survey or a set of blueprints. The rule of thumb is you nearly always need extra. This is why it costs a certain amount for a plumber to drive to your house: it takes a good amount of skill and risk to have what you need on his truck. Much less you and the other four customers of the day.

bernard · 11-22-15, 05:20 AM

Hi Jeff,

I agree with the truck comparison.
However, my initial question was not related with a specific project, neither I plan to install the swh system.
I just wanted to know in general, how much thermal energy could a swh system of a certain size, and specifications generate at specific location. That is all.

I've made testing on a couple of examples of residential objects (ground story only, up to ground story plus first, second story).
If height of the story was not more than 3 meters, I've found that an initial assumption of 5 meters per story (for supply) and 5 meters for return, got me in a ball park.
Of course it overestimated the length, when collectors were located exactly above the storage tank.
And it also underestimated the length when collectors and storage tank were located at different corners of the house.
I did not make any testing for the drainback systems, only pressurized ones.

But all in all, it gave me a pretty decent assumption, which I am using as an input for NREL SAM solar water heating application and its input: "total piping run".

11-21-15, 09:56 PM	#21
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	This question reminds me of a question rookie communications techs asked me about how much equipment they should stock their trucks with to cover daily job needs. You know, because it costs so much gas to drive all that extra stuff around. My question in return was this: If you want to spend lots of time on the road, don't load your truck with anything extra. That way, you can drive to your heart's content finding something to complete your jobs. If you want to get promoted, load your truck with all the stuff the whole team might ever need. Then we can trade with each other when I have something you need or vice versa. Much like your situation regarding plumbing, you never really know exactly how much piping or what specific fittings will be needed without some sort of site survey or a set of blueprints. The rule of thumb is you nearly always need extra. This is why it costs a certain amount for a plumber to drive to your house: it takes a good amount of skill and risk to have what you need on his truck. Much less you and the other four customers of the day.

11-22-15, 05:20 AM	#22
bernard Lurking Renovator Join Date: Sep 2015 Location: Hungary Posts: 22 Thanks: 9 Thanked 0 Times in 0 Posts	Hi Jeff, I agree with the truck comparison. However, my initial question was not related with a specific project, neither I plan to install the swh system. I just wanted to know in general, how much thermal energy could a swh system of a certain size, and specifications generate at specific location. That is all. I've made testing on a couple of examples of residential objects (ground story only, up to ground story plus first, second story). If height of the story was not more than 3 meters, I've found that an initial assumption of 5 meters per story (for supply) and 5 meters for return, got me in a ball park. Of course it overestimated the length, when collectors were located exactly above the storage tank. And it also underestimated the length when collectors and storage tank were located at different corners of the house. I did not make any testing for the drainback systems, only pressurized ones. But all in all, it gave me a pretty decent assumption, which I am using as an input for NREL SAM solar water heating application and its input: "total piping run".