any advice welcome

skinnycrow

Hi, just got our house to foundation blockwork level. It is 130sqm ground floor area and is a 2 storey.
We have a heating consultant coming soon and I wondered if anybody could
point me in the right direction as to what questions we should be asking.
We are intending to install underfloor heating downstairs with rads upstairs.
Also a solid fuel Rayburn or similar plus solar as well as a oil burner for back up.
I guess it's a big subject but any help would be appreciated.

Mike

imitation

Is the rayburn going to have a backboiler, will it be on all the time ? Your choices look solid to me rayburn aside.

skinnycrow

Hello, yes the Rayburn will have a back boiler, on most of the time I should imagine except for summer.

mike

imitation

I that case I think your biggest problem might be too much heat, rayburns and agas hail from the days of draughty old farm houses (I`m living in one now with an old oil aga), and they can pump out some serious warmth. I would be asking your consultant about using that heat effectively and keeping that room at a comfortable level . Best of luck

skinnycrow

Yes they do throw the heat out, using it all effiecently as poss is where we need the advice. Thanks for your advice.

Mike

alfie123

Hi folks have any of you guys installed a Rayburn and underfloor heating. I was on to the Waterford Stanley peops and they advised me that the Rayburn solid fuel cant be used for Underfloor heating. Has anyone done this in a 3500sq ft 2 storey.

quentingargan

I decided against underfloor heating because I'm not that fond of the slow response time. It depends on the way you use your house, but if you decide its chilly and fire up the Rayburn, it will take a while.

I've another question about sizing radiators. Now that our houses are much better insulated, surely our radiators can be a lot smaller than they used to be? After all, we have more than halved the heat loss. Has anybody done an estimate on how much you can scale down radiators for B1 or A3 rated house?

alfie123

My intention is to have an oil burner as well just to keep the heat in the storage tank topped up during the day. My plan is to light the rayburn at around 5 in the evening and it will be going strong with top quality turf until around 1 or 2.

quentingargan

alfie123 wrote: »

My intention is to have an oil burner as well just to keep the heat in the storage tank topped up during the day.

If you have solar, you shouldn't really need to do this during the summer, and the heating will do this at night in the winter. Modern cylinders are so well insulated, you won't really lose heat over a 24 hour period.

alfie123

I have been thinking of the solar option aswell just for the summer to keep hot water for showers etc, but i definatly want the Rayburn as it is a country home and it will be a good pratical feature in the house

gman2k

alfie123 wrote: »

I was on to the Waterford Stanley peops and they advised me that the Rayburn solid fuel cant be used for Underfloor heatingy.

Not even if you use a buffer tank?

selfbuild123

gman2k wrote: »

Not even if you use a buffer tank?

I have the same problem I am also trying to find out how to integrate this system. Can you use a buffer tank. How does the Rayburn solid fuel heat this? Can you integrate a gas condensing boiler into this system as well?

quentingargan

selfbuild123 wrote: »

I have the same problem I am also trying to find out how to integrate this system. Can you use a buffer tank. How does the Rayburn solid fuel heat this? Can you integrate a gas condensing boiler into this system as well?

Underfloor heating works on the basis of a low level of heat over a long period of time. There is no reason why solid fuel couldn't be incorporated into this via a buffer tank, using a mixer to bring the temperature down to the level required for UFH. You could integrate anything you want into a buffer tank, but just bear in mind that you need to be able to gravity feed that tank from the solid fuel, and 1,000L of water weighs a ton - literally!

I'm not sure that UFH is the holy grail. It tends to keep your house hot, even when you aren't there, or are asleep. The response time is very sl. ow. I personally prefer radiators, and in a modern well insulated house, these don't have to be as big as they used to be. You could also consider in-wall radiant heating as an in-between solution.

But I have an issue that if the sun suddenly comes out and starts heating the house, it is too late to shut down the UFH, and you just end up opening the windows. Give me radiators and room stats any day

tipperary

quentingargan wrote: »

I decided against underfloor heating because I'm not that fond of the slow response time. It depends on the way you use your house, but if you decide its chilly and fire up the Rayburn, it will take a while.

I've another question about sizing radiators. Now that our houses are much better insulated, surely our radiators can be a lot smaller than they used to be? After all, we have more than halved the heat loss. Has anybody done an estimate on how much you can scale down radiators for B1 or A3 rated house?

In terms of sizing radiators, the alurad website includes a radiator sizing section which allows things like double glazing, extra insulation etc to be considered. Not sure how well the results would work for steel radiators though.

beyondpassive

quentingargan wrote: »

But I have an issue that if the sun suddenly comes out and starts heating the house, it is too late to shut down the UFH, and you just end up opening the windows. Give me radiators and room stats any day

Its putting the cart before the horse to specify a heating system before specifying the house materials. The most appropriate approach is to build a house that provides a stable indoor environment and minimises the need for heating, by detailing continuous insulation and cold bridge free airtight details. Any heat loss that cannot be addressed is compensated for with the heating system.

If you design using high levels of insulation and heat recovery ventilation you will have stable levels of thermal comfort with the structure acting as a buffer holding 19-21 degrees year round. Its not difficult to do this yet there is huge resistance from our building industry and professionals.

Look at it like having a big innefficient car, it needs a big engine to rev up on the inclines and needs heavy break pads to slow it on the decents. Alternatively a house designed to be airtight and thermally consistant with natural materials not Polyisocanurate or glass fibre, will act like a car with a massive flywheel, the energy from the decent is stored for the climbs. This thermal inertia is like what happens in a wine cellar, day night variations in temperature are evened out.

Good triple glazed windows and dense roof insulation such as 60 softboard and 280 cellulose will keep solar heat gains down. The low grade underfloor heat will keep stone or ceramic floor above ambient and this heat will be distributed by the heat recovery ventilation.

Simple smooth comfort, big buffer tank, not a boiler and rads ramping up every 4 hours and cooling down because there is no insulation betwwen the rising wall and the inner leaf. is there?

fergus.wheatley

Air source heat pump into a buffer combination tank (at least 1000 litres). This provides a buffer of heat for the underfloor heating and gives pressurised hot water without a much lower legionella risk. The buffer an take multiple sources of heat including solid fuel (via a intermediate veneted cylinder) and solar.

you might find the following diagram interesting. If you pm me, I'll send the pdf that goes with this.

BTW, I find underfloor heating with a thin screed (50mm) has a lag time of about 1 hour so can be switched on and off like a regular heating system.

skinnycrow wrote: »

Hi, just got our house to foundation blockwork level. It is 130sqm ground floor area and is a 2 storey.
We have a heating consultant coming soon and I wondered if anybody could
point me in the right direction as to what questions we should be asking.
We are intending to install underfloor heating downstairs with rads upstairs.
Also a solid fuel Rayburn or similar plus solar as well as a oil burner for back up.
I guess it's a big subject but any help would be appreciated.

Mike