System design for own home!

[Matthew Score]

We are just about to extend our house and thinking over what system to install.

Currently our household consists of myself, my wife and our 3 year old daughter.

When finished the house will be 5 bed with one main bathroom, ensuite and a downstairs ensuite.

I have mulled over using air source but I have heard horror storeys about large energy bills.

Thinking a gas boiler is the way to go.

Downstairs will be UFH with radiators upstairs and electric underfloor heating to the bathrooms with wet towel rads.

Given the 3 bathrooms I am thinking Unvented cylinder is the only way to go but space upstairs is limited, the only place downstairs would result in a long draw off for the main ensuite which will be the most used bathroom.

That leaves the loft, which has low head room of about 1.5 meters, I have never fitted a horizontal cylinder and head they aren't great due to stagnation.

May be a storage combi in the loft on the gable wall, which would give an equal draw off to all outlets (on a water meter)

I have no experience of storage combi's but have been looking at a intergas boiler that uses a small cylinder to pre heat the water which is meant to give great out put for water. Also the boiler can be set up to have 2 different outputs depending on the demand.

Currently our water usage is isolated to 2 showers in a morning and a small bath in the evening for our daughter so not a great demand but we are hoping to have another child once we finish the building works and as both children get older that demand will increase so I want to future proof our system with out wasting energy heating a cylinder to not use it.

I am also thinking with 3 zones a LLH would be required.

In regards to controls I was thinking of using the drayton wiser Trv's to effectively zone the upstairs and the main controller for the UFH.

I have really over thought this and got my head in a right muddle.

If any of the above makes sense what are people's opinions?

 

[Chalked]

Hi
If I could do my own house from scratch I would do the following.
No air source, or ground, or biomass. Loads to go wrong and most have horrendous bills.

Gas system boiler.
Underfloor downstairs in screed. Controlled by neostats.
Rads upstairs fed through an underfloor manifold, with Heatmiser neostats ( hardwired in each room) these then open and shut the manifold heads ( no mixer required)
Low loss header next to boiler with three separate zones . One contestant temp for hot water, one constant temp for upstairs rads zone and one through a essbe mixing valve to give weather compensation to the underfloor.
Fit a horizontal cylinder in the loft, or vertical where you can. Fit a secondary hot water circuit and take towel rails off this ( need to be non ferrous)

 

[ShaunCorbs]

Also destrat pump on the cylinder to give better temp

 

[Welder]

Also destrat pump on the cylinder to give better temp

Agree but did you mean constant temp & bigger capacity?

Hi
If I could do my own house from scratch I would do the following.
No air source, or ground, or biomass. Loads to go wrong and most have horrendous bills.

Gas system boiler.
Underfloor downstairs in screed. Controlled by neostats.
Rads upstairs fed through an underfloor manifold, with Heatmiser neostats ( hardwired in each room) these then open and shut the manifold heads ( no mixer required)
Low loss header next to boiler with three separate zones . One contestant temp for hot water, one constant temp for upstairs rads zone and one through a essbe mixing valve to give weather compensation to the underfloor.
Fit a horizontal cylinder in the loft, or vertical where you can. Fit a secondary hot water circuit and take towel rails off this ( need to be non ferrous)

Personally, I'd also have a compensated flow system for the upstairs too. That will reduce bills overall.

The one thing I'd def do in addition is have solar PV on the roof but with the open vented cooling built into the panels. That gives you a low maint solar water source to reheat the water, PLUS significantly higher electrical output due to the PV panels being kept at a lower temp if you wish to use/store it.

If govt does what it says and moves away from gas then it gives you alternatives too.

To me, on a project like this, I would both get a full heat calc done AND I'd insulate the whole place to within an inch of its life. For every penny you spend on that it wil pay back hundreds of pounds over time.

 

[ShaunCorbs]

Yes eg more hot water stored instead of the 65% capacity normally