Central Heating Plan for Large House

[Dan Robinson]

can we assume that moving to one big system should be more efficient to run than for separate standalone ones?

One big system but with two or three small boilers linked together.

Don't assume that your current set up was correctly sized too.

Been talking about it a lot recently on here as it is my pet project for the summer, but we're doing an installation at the moment where the builder was convinced he wanted 40kW in the house (his own place). When the calcs were done, 15kW was the heat load at design temps. So this lot is in the process of being installed (ignore the wires - they're the Spark's). A boiler that can only do 24kW (although a few tweaks will get me 28 if I want it ). Even then, that is at his insistence - I wanted to put an 18kW unit in.

This is why I mentioned earlier, that you need to get the foundation information correct before tearing headlong in preconceived design ideas. This might well cost you a few hundred up front, but is likely to save you thousands in the future.


Remember also, that systems are sized for worst case scenario, which in the SOuth East only happens a couple of weeks a year. The rest of the time, the system is grossly over sized and therefore runs sub optimally.

 

[dilalio]

Got to admit Dan, loving the crimp fittings, what brand do you use? How do you find getting to joints in tight spaces - against walls etc?
Nice clean pipes, no green shyte and saves the hot works permit bother!

 

[dilalio]

OP: As has been said above, it's great that you are taking a keen interest in the system you think you'll need, but you really do need to bring in a design and install team and have drawings made.
There are so many different ways that this can be realised and each proposal will be different - by going too far into it, you'll find yourself second-guessing whoever you bring in, in effect, pitting yourself against them which won't bode well for a happy project.

If I were you, I'd be approaching local architect firms or owners of similar properties (or both) and try and get some viewings of installs and recommendations for firms that have undertaken such works in your area.

It also might be worth considering a solution that utilises more than one boiler so that you have some backup in the event that one breaks down! - just a thought

 

[Dan Robinson]

Got to admit Dan, loving the crimp fittings, what brand do you use? How do you find getting to joints in tight spaces - against walls etc?
Nice clean pipes, no green shyte and saves the hot works permit bother!

Either mappress or xpress. You have to plan carefully as it's easy to plumb yourself into a corner, but using Unistrut gives you more options too.

Love the stuff.

 

[dilalio]

Will the tool work for both brands?
Or do you need one for each?
Which tool do you use? Not cheap are they

 

[Dan Robinson]

I have a 2 series and 3 series Novopress. Works with a M profile brands of which there are a couple. Stainless steel too with is great for external gas runs where the p|keies will have copper off the wall as quick as you can hang it.

Certainly an investment.

 

[Agile]

I would start by asking how many people are going to be living there!

That will help to define the HW requirements.

Measuring dynamic water supply capabilities will get the water supplier on the job earlier of upgrading the local distribution.

Better also wait until the autumn to ensure that EDF go ahead with Hinkley Point.

Tony

 

[Razor900]

Surely the hot water requirements for the property should be calculated on the available draw offs and not the number of people living there??

So if the OP is on his own he could probably get away with a 24kW combi

 

[Agile]

If he is there on his own then a 24 kW combi will suffice regardless of the number of HW outlets. He can only use one at a time.

On the other hand if its to be a B&B then he will need to guess at the diversity factor and design accordingly. I use 50 li plus 50 li per person stored. Assuming a fair recovery rate.

It is surprising how many large houses I see with only a couple of people there.

 

[ianmcd]

yep tony so he gets a 24KW combi and then tries to sell the house, you design heating systems for the property not the person what if you get a recluse that never washes do you just give him a fan heater ?

 

[Razor900]

yep tony so he gets a 24KW combi and then tries to sell the house, you design heating systems for the property not the person what if you get a recluse that never washes do you just give him a fan heater ?

You don't see the beauty of it Ian

For every person that moves in you simply install another 24kW combi and gradually build it up until the whole house is heated - you get redundancy and fantastic hot water delivery as each tap gets it's own boiler!!

@Steelmasons bet you've never thought of this idea, you're such a dinosaur with your big pipes and calorifiers this is out the box thinking at it's best

Tony don't ever change

 

[ianmcd]

Ha Ha razor you should be in sales

 

[Steelmasons]

Nice clean pipes, no green shyte and saves the hot works permit bother!

Wipe down after soldering so no excuse for green shyte...no hot works permit required on these type contracts..
Dan is fully aware of what I think of pressfit shyte....your above comment is hardly an excuse to use press shyte as opposed to soldered fittings...
Hey Dan , get that insulated pronto....

 

[Steelmasons]

yep tony so he gets a 24KW combi and then tries to sell the house, you design heating systems for the property not the person what if you get a recluse that never washes do you just give him a fan heater ?

You don't see the beauty of it Ian

For every person that moves in you simply install another 24kW combi and gradually build it up until the whole house is heated - you get redundancy and fantastic hot water delivery as each tap gets it's own boiler!!

@Steelmasons bet you've never thought of this idea, you're such a dinosaur with your big pipes and calorifiers this is out the box thinking at it's best

Tony don't ever change

That's two keyboards fooked in the space of an hour...

 

[Steelmasons]

@Steelmasons bet you've never thought of this idea, you're such a dinosaur with your big pipes and calorifiers this is out the box thinking at it's best

I think I may have oversized the hot water requirements for this 7 bathroom job .....the house will be on the market to be sold once the works have been completed....I guess I could have speced the hot water requirements for 3 people and saved the owner a few quid....gonna rip the 1000 litre storage cylinders out and replace with 200 litres....may as well rip the VAILLANT 200kw rig out and replace with a 624......I'm sure most of the house won't require heating when only 3 people living there..