Tuesday, September 25, 2007

Some more progress on heating, leaves turning


Here is the boiler and water heater with much of the piping done. The crooked vertical line coming out of the water heater is thanks to the not-square fitting welded onto the water heater. The domestic water piping is not done yet, but one step at a time. The board to the left of the water heater will house the domestic water mixing valve and the mixing valve and circulating pump for the kitchen radiant zone. Yes the air separator is much bigger than our 3/4" line size, but it was in the original piping system, so the price was right.

Here is the return manifold. The red and blue PEX lines on the left of the picture are the domestic water lines for the plumbing systems. We have seven zones plus a spot for a spare. The orange PEX line is the 3/4" main return line for the manifold. The water in the manifold flows from right to left into that orange line, back to the boiler/water heater. The silver valve on the extreme right hand side of the manifold is the differential pressure bypass valve. The supply manifold will live above the return, look for that picture later this week. The PEX lines make that big U-shape to prevent gravity flow (sometimes called "ghost flow"). If you really want to understand what that is all about, post a comment here and billn will expand on it. But it is boring for lay-people so billn will not post about it today.


Here is a tree across the street from billn's work. Billn took this picture early this morning, September 25, 2007. This picture reminds us why we live in VT.

9 comments:

Anonymous said...

It looks like you are making pretty good progress. Any predictions for when the house will have a functioning heating system--other than the all the hot air you vent when you are running your mouth?

brooklyn barrister

Bill N. said...

I figure if we obtain some of your legal-state-worker speak, I could stop work all together.

We might have heat in two weeks.

One person suggested we heat the house with more cats. I am not down with that one.

JenM said...

Now if we could just funnel these snide jabs into heat production we would be in business....

I will post pictures everyday of my freezing children!

Anonymous said...

ooh ooh! I want to know about ghost flow.. sounds very Halloweeny

Anonymous said...

My "snide jabs" amount to about a popsicle stick's worth of heat. I could send you one in the mail that you could use for heat production--I guess I owe you two now after this posting.

brooklyn barrister

JenM said...

BB don't sell yourself short, we all know you have at least a truckload of popsicle sticks waiting to come out. Bring 'em.....

Bill N. said...

Ghost flow? It isn't spooky, but it would be cool if it was.

Ghost flow is when zones that are off (not calling for heat) end up warm from convection of warm return water from other zones.

If the return connections were vertical straight down, a non-calling zone can be warmed by other zones (whose hot return water is flowing from right to left in our manifold).

This hot water can flow vertically upward (warm water is less dense than cool water, so it rises). Even though the supply side of the zone is closed, you can experience bidirectional flow in the piping (very low flow of course).

This bidirectional flow can make baseboard convectors feel warm, which in summer or intermediate weather is annoying.

The U-shape to our return tubing is an effort to thwart this ghost flow. The ghost flow would now have to flow down, then up. This is not likely, since warm water is less dense and it rises, not falls down and then rises. This method is a much less expensive way than using weighted check valves (the traditional method of preventing ghost flow).

Boy that was boring.

JenM said...

Billn, next time try harder to make this ghost flow topic more interesting!

Try this, when you are telling these litte stories, have a point!

Anonymous said...

I didn't think it was boring... long winded .. you could have made it scarier