Is my boiler setup and plumbing sound?

Steve_Smith007

Hi. I have a 900 sq ft house in Detroit MI. It has 2 bedroom, one upstairs. There are 7 baseboards in the house. 4 are roughly 6' long. 3 are in the family room and total 30' in length.

I bought a 60,000 btu Weil McLain boiler. I also bought a 6 port manifold made by mr pex and 300' of 1/2'' pex al pex with compression fittings from mr pex.

I was told my a technician in the area that I need to ditch the manifold and 1/2 pex al pex and run one loop of 3/4'' pex al pex instead.

I was hoping to hear from others whether or not my original idea was sound. I already have the manifold and 1/2 pex al pex. Should I ditch them in place of one loop of 3/4'' pex al pex all the way around?

Thank you.
-Steve

Leon82

You can use the manifold, it will ensure that each radiator gets the same temp water. He probably doesn't want to run the extra pipes(if he is doing the install).

Jus make sure you have valves so you can purge each run

Steve_Smith007

Yes, the manifold has valves. My plan is to open and purge one at a time.

I think I'm installing a more intricate and 'newer age' design then what some of the installers out here are use to quoting. If they bid the job and did one long loop of 3/4'' pex al pex, it would be a much quicker install and about $500 cheaper without the manifold and extra pipe and fittings.

The 4 technicians I spoke to all asked why I would choose to use 1/2'' pipe, and I didn't really have an answer other than my manifold outlets were 1/2'' and I read on hvac forums that many in the industry assume 3/4'' although 1/2'' will work fine for a manifold setup.

Thanks for your reply.

I still have to order a pump though. It was suggested I get the smallest recirculating pump or get whatever the bonnet plate on my boiler specifies. Have any advice?

Leon82

You're only feeding 1or2 radiator with each 1/2 loop so as long as it's not more btu than 1/2 can support you will be fine.

Steve_Smith007

Yes, I am only feeding 1 or 2 baseboards with each loop.

Any advice on pump would be appreciated! Taco 007 or 008? I'm at a complete loss on what size pump to get. It's the last item I need to buy.

Leon82

You need to know how you're going to pipe the near boiler piping first.

Steve_Smith007

I'm piping to pipe 1'' black pipe from the boiler to the manifold. I'm going to hang the expansion tank on the black pipe under an air scoop. The manifold is about 4' from the boiler.

I just purchased a 3 speed grundfos 1/25 hp pump. Think this will do the trick?

Paul48

If you're using a scoop, make sure you follow the piping directions for it, or it's useless. Does the manifold have circuit setters?

Steve_Smith007

No it does not have circuit setters (I don't know what circuit setters are fyi). This is the manifold I'm using. It says max temp is 194F, but supply house said I could use it for my hydronic heat application.

http://www.supplyhouse.com/Bluefin-HM6-6-Loop-Stainless-Steel-Radiant-Heat-Manifold

EBEBRATT-Ed

you need to slow down and design this correctly. If you want it to work when your done you can't guess at what components to use.

1st ......heat loss
2d........pick water design temp and deltaT
3d........ size and place heat emitters
4th......... make a piping diagram & size pipe
5th..........determine flow and head loss
6th...........select pumps
etc. etc


Skip a step or guess & it won't work right

Steve_Smith007

I'm already going above and beyond on this project ed. You'd have to know the circumstances, but this is a blue collar neighborhood just north of 8 mile. There's a possibility the tenant will move out in the middle of the night and let everything freeze. There's also a good chance the tenant will get a gas credit to make up for the system not running at 100% efficiency.
If this was a large house in Bloomfield Hills I'd agree with you. I'm about to have 1.6k into a system that a pro would have charged 5k+ for.