Central Heating Design

[Toad555]

Hi

 

I have a single pipe central heating system installed on my boat, the main circuit runs all the way around the boat in 22mm pipe.

The system is heated by a 5kw Webasto unit.

 

It actually works really well except for two issues.

1. It's quite cold in the middle of the boat where my office is so I'd like to add an extra radiator there.

2. The system is a nightmare to bleed because the pipe work goes up and down so much. Hence why I'd like to straighten out some of the pipework as part of this proposed work.

 

My question is, should there be restrictions in the 22mm pipe between where radiators are currently installed.

Most of the system is 22mm finrads which are obviously in the main circuit but there are currently two standard radiators, both have a reducer in the 22mm pipe between them.

I assume this is simply to force water flow around the radiator but is it really necessary? 

[Tony Brooks]

OK, I will jump in with my thoughts but possibly Mikes the chap for a definitive answer

 

A single pipe system feeding radiators relies upon hot water rising up the inlet rather than the pump. On the single pipe systems I have seen the radiator outlet T into the 22mm had sort of venturi to help draw water out of the rad. The single pipe also ran at floor level so no idea where the ups and downs come in or restrictors between rads.

 

Finrads seem to produce little heat output compared with a radiator so maybe the rads are afterthoughts to try to improve the heating.  As its a single pipe system and the 15mm pipe lengths are short I think I would be tempted to try piping the rads in series with the Finrads so all the water flow passes through them with no restrictors. Then all the pipes could be at floor level.