Low loss header v.s. Closely spaced tees

fricard

Why would I want to use a low loss header for a system with a Burnham Aspen 155 boiler, seven zones of staple up radiant with plates, one small baseboard zone, one indirect water heater, and zoning with circulators. The radiant design calls for a low loss header. I have always used closely spaced tees and have never had a problem that I know of. There is a big price difference which I don’t mind spending if there is a performance benefit. Space is not an issue.

kcopp

In addition to they look cool... You can do air removal, dirt separation and save some space.

clammy

It depends on space for myself ,if I do not have enough height or space for the proper distances before and after my closely spaced tee s then I ll jump to a hydro separator it makes life simpler and usually frees up room for proper pump distances and such. If you have a lot of space then go for the tees it is cheaper but I ve found that it’s easier w the separator . A lot depends in some cases I by pass it all and use a 4 port buffer tank then there’s no issues and u get some buffering for the micro zoning . My days of ps on mod cons are just that in the past either separator or buffer and personally I ll go w cast iron boilers over mods unless all radiant or low temp much happier customers,less maintenance and longer excepted life span then any wall hungs and usually less head aches all around which leads to happier home owners and less cost and possibly a better rio .
Peace and good luck clammy

Jamie Hall

Another potential factor -- cost and experience. Not of the materials (closely spaced tees are going to be less!), but of labour. A low loss header can be installed more quickly and by less skilled help, and this can make a big difference, depending on your local labour rates.

GroundUp

LLH take up WAY more space than CST and take twice as long to install in my experience. But they do look really cool and offer more versatility and function along with what I feel is a better hydraulic separation. The Caleffi versions leave a nice 1/2" port for a system sensor which I find to be an excellent place for a tridicator gauge.

john123

If you are trying to make a mod-con boiler as efficient as possible, would the closely spaced Tee's make it more efficient than the low loss header because the return water would be cooler. Does not the low loss header warm up the return water?

hot_rod

A low loss header is closely spaced tees, in a larger size. The temperature blend will be the same in either component.

You have only 3 conditions possible in tees or seps. Equal flow, higher boiler or higher distribution. So the temperature blend depends on which condition. With multiple zoned loads, that mixed temperature
, flow rate difference changes. Here is the math to predict those temperatures.

My Lochinvar has a variable speed boiler circ, so the control will watch the boiler return and adjust for the lowest allowable return, does the Burnham? If your goal is the lowest possible return, best boiler efficiency, that is one measurable way to get it.

hot_rod

the water doesn’t know if it is going thru tees or a vessel like a separator/ llh. One of these 3 conditions is present when flow is moving.
How could it not be?