How many radiators off a 22mm flow

[SJB060685]

Oversize rads and pipes to allow for future heat sources, with higher flows at lower temps.

Whereas I would normally agree with you have a look at his loads above. He’s around 38KW. Unless massive insulation upgrades are made I wouldn’t even consider a heat pump just yet.

 

[b21playa]

Oversize rads and pipes to allow for future heat sources, with higher flows at lower temps.

Rads are oversized for rooms

 

[b21playa]

Whereas I would normally agree with you have a look at his loads above. He’s around 38KW. Unless massive insulation upgrades are made I wouldn’t even consider a heat pump just yet.

Heat pump? I’m lost sorry

Currently the pipework under the floor has a hessian type insulation, this is being replaced with 20mm walled insulation

 

[SJB060685]

Heat pump? I’m lost sorry

Currently the pipework under the floor has a hessian type insulation, this is being replaced with 20mm walled insulation

That was a response to someone else’s comment about sizing radiators for low temperature systems. A heat pump is a low temperature system but that doesn’t mean a gas boiler can’t be either. My point was with your loads at around 38KW a heat pump is not a viable option and you could size the radiators for low temperature on gas boilers but these radiators would be much, much bigger. Finding a reference room to size the radiators in your case would be tricky.
I would ignore that comment and this as it was a response to someone else’s proposed option.

 

[b21playa]

That was a response to someone else’s comment about sizing radiators for low temperature systems. A heat pump is a low temperature system but that doesn’t mean a gas boiler can’t be either. My point was with your loads at around 38KW a heat pump is not a viable option and you could size the radiators for low temperature on gas boilers but these radiators would be much, much bigger. Finding a reference room to size the radiators in your case would be tricky.
I would ignore that comment and this as it was a response to someone else’s proposed option.

Thank you

 

[ShaunCorbs]

22mm will be on the boarder of doing it around 1.1ms

 

[SJB060685]

22mm will be on the boarder of doing it around 1.1ms

And increase to 28mm will reduce velocity but increase materials cost. You have to way up the pros and cons. I would not be overly concerned with a velocity of 1.1, it’s nowhere near max recommended and to be honest no system is 100% perfect

 

[b21playa]

I'll go with the 22mm for now and see how I get on, can always upgrade later when the boiler is being changed

 

[b21playa]

Just a quick update on the thread. Managed to remove old and install new rads this weekend. All pipes insulated with Bylaw stuff and what a difference it has made