Doubt about radiator heating with manifold

[pitagoras]

Hi.
I´m about to install a central heating in my house.
In each room there will be two radiators (so that heat is better distributed).
My idea was to use a manifold to distribute pipes to three rooms (so the manifold would have 3 "outgoing" and 3 incoming connections.
The piping will be pex.
What I´m not sure is how to connect the 2 radiators in each room. Should I connect them in parallel or in series?
If I connect them in series I care about the second radiator receiving water not hot enough.
If I connect them in parallel both would receive water at the same temperature, but then I have to use "T" connectors for the pipes (which is not the idea when using a manifold...)
Any advice?
Thanks!

 

[SimonH2]

You also need to think about how you are going to control them. Parallel will mean two TRVs per room, or rigging up one of the tees to be between the TRV and rads.

If you put them in series, you might be surprised. If the heating load is significant then there will be a fair flow rate through them and the second rad, while not as hot as the first, will still get fairly warm.
As the TRV throttles down, then the second rad will get progressively cooler as the outflow temp of the first rad drops.

 

[mogget]

Personally I wouldn't go for 2 rads per room. I'd just put one larger rad under the window, this keeps condensation from forming, and the heat will be even enough.

Can you get skirting board heating for a reasonable price in Argentina?

 

[bolshy]

These manifolds, are they prefabricated? Are your pipes going under the floor, or dropping down from above? I'd still pipe up in parallel from the manifolds. Easier to balance and total control of room temp via radiators that require TRVs. No point in cutting corners. With the variety of pushfit and threaded/ compression union brass manifolds on the market, there are many options. Get a reel of PEX and go to town on it. Don't forget your pipe inserts.

 

[pitagoras]

Personally I wouldn't go for 2 rads per room. I'd just put one larger rad under the window, this keeps condensation from forming, and the heat will be even enough.

Can you get skirting board heating for a reasonable price in Argentina?

I can get skirting boards but there is no local manufacturer; also the most common thing is aluminium radiators, and has been for a long time. I want tomething that remains standard/replaceable for a long time.
Are they much better?

 

[pitagoras]

These manifolds, are they prefabricated? Are your pipes going under the floor, or dropping down from above? I'd still pipe up in parallel from the manifolds. Easier to balance and total control of room temp via radiators that require TRVs. No point in cutting corners. With the variety of pushfit and threaded/ compression union brass manifolds on the market, there are many options. Get a reel of PEX and go to town on it. Don't forget your pipe inserts.

I didn´t buy the manifold yet, but I think the quote I have is for one assembled from modules. Pipes will go under the floor (concrete).
So if I understand correctly, I should put a manifold with one circuit for each radiator rather than for each room.... Maybe you´re right and it will be cheaper in the end.

 

[bolshy]

You can install the manifolds however you like. You could have two 2 port manifolds supplying each room. I am saying each radiator should have it's own flow and return to get the best from your heating. If these pipes are to be buried in concrete, make sure it's as you want it, difficult to change anything later. And make sure it's all pressure tested before the concrete goes down.

 

[pitagoras]

You can install the manifolds however you like. You could have two 2 port manifolds supplying each room. I am saying each radiator should have it's own flow and return to get the best from your heating. If these pipes are to be buried in concrete, make sure it's as you want it, difficult to change anything later. And make sure it's all pressure tested before the concrete goes down.

Thank you and everyone for the advice!