Closely Spaced Tees, Low Loss Headers & Buffer Tanks - When, Where, Why

Presented by John Barba, Dave Holdorf, and Rick Mayo
The right approach to piping a multi-zone system with a mod-con boiler can make all the difference. Do it effectively and you have a system that purrs like a kitten and provides your customer with years of optimal efficiency, performance, and comfort. Do it wrong, however, and you may have just planted a time bomb in your customers’ basement - and an inefficient one at that.
In this fast-paced, fact-filled session, you’ll learn the finer points of piping a mod-con boiler, including when to use a primary-secondary “moose-antler” piping arrangement, when to use a hydraulic separator and when to use a buffer tank (you’ll also learn how to size one).

[@bajatoma]

Watching this makes me think that I just stroke a gold mine! Much appreciated! I'm not even a plumber or heat specialist. Subscribed! I was learning the system, and found a number of issues. Very happy to see you covered circulator speed selection, as my plumber who installed the system had it set to speed 3, and learning about all those delta T and how to read system pressure drops and pump gpm vs pressure drop, I realized that it had to be set to speed 1. Besides that the boiler is way oversized, and I might be looking into installing buffer, and you covered how to calculate the size and all. Very good teacher, you made my day. Fingers crossed I'll find more of your stuff on youtube.

[@TacoHVACtv]

We are so glad you enjoyed your experience! Our team of experts strives to put out educational and fun content. Glad to have you aboard!

[@drofdoowegroeg]

Question: First off great explanation, I learned a lot! I am using a combi Navien unit. The Navien manifold is very expensive. Do I really need it? Can't I make my own as long as I closely space the tee's similar to the Manifold they offer? It looks like in the diagram you showed, it does not use the Navien Manifold? I am doing all the other plumbing myself, so why not the manifold part as well? It seems like in most of the videos I watch, they always use the Navien manifold, but do all the rest of the plumbing themselves?

[@TacoHVACtv]

First off, thanks for watching Taco Tuesday! So yes, the idea of the webinar was to discuss the differences and the similarities between closely spaced tees, hydraulic separators and buffer tanks. Choosing one method over another is based upon the system you have in the house. Secondly, to answer your question, yes, you can make your own header as long as you follow the piping practices that Navien wants

[@hobson3724]

Thanks for the lecture. very valuable

[@TacoHVACtv]

You are welcome!

[@thierryrayaisse3153]

Where would you add a hydraulic separator in a buffer tank configuration. I guess it would be a primary/Secondary/tertiary system. Appreciate your insight. thx

[@TacoHVACtv]

Is the question "Why would you add a hydro-sep in a buffer tank system" or "Where"? A buffer tank and a hydraulic separator act the same and can be interchangeable is certain situations. I don't see the advantage to adding a hydraulic separator in a system with a buffer tank since the buffer tank is providing that separation. The only advantage of adding one to a system would be for the ease of installation since there are some hydro-seps that have air/dirt/magnetic separation already built in.

[@tinoslish4032]

When you used a 10-1 turndown ratio what were you referring to

[@TacoHVACtv]

We are referring to the boiler technology in the firing rate. Many of the newer wall-hung type boilers have a turn down ratio. For our example of 10-1, if the maximum btu firing rate was 100,000 BTUs per hour, then the lowest would be 10,000 BTUs per hour.

[@bryanswanson5007]

wondering why they recommend piping the indirect off of the primary loop rather than after the hydraulic seperator off the system manifold. Ive seen many and even have installed a few years ago after the seperator and they work just fine as far as I can tell.

[@TacoHVACtv]

@bryanswanson5007, first off, thanks for watching Taco Tuesday, greatly appreciated. To answer your question, it is suggested to take off for the DHW indirect tank tank first to allow all of the energy the boiler is making goes to generating hot water for the house. It will depend upon several factors like the size of the indirect tank and the size of the boiler. It may also lie with the control sequence that the boiler manufacturer has in their control logic. And that is the beauty of hydronic heating, we have lots of options to achieve the same thing!

[@aliatas6647]

The 4" & 8" distance either end of the Tee, is that straight pipe to the next elbow? Or is it before connecting into the boiler?

[@TacoHVACtv]

The 4 and 8 is referencing pipe diameter so if you have 1" pipe, it would mean 4" and 8". Anyway, the 4 and 8 references before any other fitting in the pipe whether it is a tee, elbow, coupling or even a valve. This design is to have the proper type of flow internally as well as the hydraulic isolation desired.

[@aliatas6647]

@@TacoHVACtv I was meant to ask 4x and 8x. Nevertheless, you have addressed the question for me. Many thanks! 😁👍

[@TacoHVACtv]

You're welcome!

[@jeriahknox5905]

I wonder why we don't we see more buffer tanks combined with DHW tanks, tank within a tank systems?

[@TacoHVACtv]

Jeriah, There are several manufacturers of buffer/DHW tanks out there. Why are they not more common? As we see the trend of low temperature hydronic heat emitters and space constraints, the popularity of these tanks may rise.

[@jasonjohnsonHVAC]

We have bipolar weather here in Austin. One day its 30°.....2 days later its 78°

[@tsetsivito]

This is a great example why you should read the educational books first and then watch such videos

[@jockster5525]

Awesome..I've got a low loss header on a commercial plant system in the UK..I can't get flow temp to hiu above 60 °c ..I'll need to upgrade the three pumps on the boilers to over come this .thanks for your efforts really appreciate your efforts

[@TacoHVACtv]

Thanks so much for joining us on a Taco Tuesday, glad we could help!

[@MustPassTruck]

Anyone brought up the idea of making parts to convert the average water heater tank into a buffer tank?

[@TacoHVACtv]

An average water heater used as a buffer tank would be used as a two-pipe buffer and has the advantage of adding mass to the hydronic system whereas the 4-pipe is used as adding mass as well as hydraulic separation. The 2-pipe buffer doesn't add the separation

[@bajatoma]

@@TacoHVACtvFor those who already have a LLH installed in their systems, but lack of mass, where would a 2-pipe buffer be installed?

[@bobzahn6802]

Buffalo New York