If you have a big kitchen-diner...

[EggHeadz]

What do you do about insulation? Both sound and heat? We're starting a renovation project that will leave us with a (very) big kitchen-diner and I'm concerned it will be cold with the big bifold doors and also noisy with minimal soft furnishings to absorb the sound. Are curtains for bifolds a crazy idea?

We have a large family room with 3 sets of large bifold and a glass roof. We installed Nu-heat UFH (wet) and so far have managed without a fitting a fire. Ours is run off the boiler along with the CH for rest of house.

We have 2 Mitsubishi air source heat pumps for a fairly large house. We have mostly wet under floor on the ground floor and conventional radiators in the bedrooms and main lounge area. Electric under floor heating in the bathrooms upstairs. We have no gas in the village. The heat pumps are cheaper than buying oil and the house is warm. We have a lot of insulation where we can have it.

The pumps are outside at the rear of the garage and are fairly chunky. They discharge cold air! The only down side is we don’t get very hot water any more but that’s no real issue. It’s hot enough. The whole system was retro fitted and only the kitchen and part of the hall was a new build recently. We have two fireplaces but don’t use them very often. More out of liking the look of the fire rather than needing it.

Yes we have it in every room, but we have an odd layout (barn conversion) - only one bedroom upstairs. We’re one of 7 Barns all converted by the same builder 10 years ago, our neighbours with more upstairs space have radiators in the upstairs bedrooms and it seems to work for them.

Our system is made by Thermia. The fan unit in the garden is about 1.5m wide 1m deep and maybe 1.2m high. Looks exactly like this: i.ytimg.com/vi/XYklEvEE554/mqdefault.jpg

Sits next to our shed with a bit of trellis in front. I can’t tell you how often the fan kicks in as we can’t hear it inside the house. It’s on sometimes when I leave for work, and well, it sounds like a big fan! It’s not massively noisy, it wouldn't stop you having a conversation next to it, but yes you can hear it - like the sound of air con in an office I guess. In the summer it rarely kicks in, so doesn’t disturb us in the garden. The newer systems have passive cooling, I don’t know the details, but this may cause the fan to run more in summer, maybe something to ask your engineer when they visit?

We have the inside unit in a cupboard in the hall (we don’t have a garage) but our neighbours have it in their attached garage. Again when the heating pump kicks in you can hear it if you are outside the cupboard, but I wouldn’t say it’s any noisier than a standard central heating system.

The biggest downside I think is the servicing. We get ours done every 2 years but you’re limited to a few specialist companies. We found some are reluctant to service units they didn’t install. I think we paid £200 for the last service, so something to factor in.

I’m not sure how it compares efficiency wise to gas - there’s no gas in our village so wasn’t an option for the builders.

If you have a suspended floor then wet UFH is a pig. You need to reinforce the floor joists so that they can support the weight of a concrete screed that can get laid over the joists (think insulation in the joists, with 25mm marine ply subfloor at £75/8x4 sheet and then screed on top before whatever finish like tiles or floorboards- you're losing 2-3 inches of room height as well!!)

I wanted to do the same as you (wet UFH on suspended floor) using aluminium spreader plates but the shop said it basically won't work. UFH works by generating a large low level thermal mass. For that you need something that can contain it: like concrete screed or stone tile floors. If your extension already has suspended floors it won't be cheap to put in wet UFH.

Also be wary of the calculations that sales-people will throw at you for ground and air source heat pumps.

If you are connected to mains gas a modern high efficiency gas boiler is almost always more cost efficient. If you aren't connected to mains gas then ground and air source heat pumps make a lot of sense. But the calcs look a little like this:

4-bed semi detached solid brick walls requires:

17,500 kWh of heating.
Air source can provide that based on a factor of 4 efficiency, so uses 4375 kWh of electricity. At 11.7p/kWh that's about £500/year.

Gas with a modern condensing boiler at 95% efficiency will cost around £550/year.

Add in servicing fee differentials, factor in that an air source heat pump rarely works at peak efficiency and finally that massive capital cost to install and if you can do mains gas, get a modern gas boiler.

Thank you for the detailed responses. We are on mains gas so it sounds like the gains are not going to be great. My thinking was that if we're going to put in wet UFH anyway then stick in a heat pump and that would power it for free effectively. I have been led to believe that the pump and installation themselves are effectively free as it's reimbursed (albeit over a long period of time) in one of these green deals. Is that rubbish then? Sounds like the cost of the electricity for the pump plus the maintenance will work out a lot over time. My thinking was though that gas prices are likely to go up over time and electricity come down.

The suspended floor has a cavity below it of about a foot that the builder was going to fill with hardcore and then lay insulation then concrete for the pipework above that. He didn't say we'd need to raise the height of the floor. Does that sound right?

Any ideas how to heat the area -kitchen + summer room- if under floor heating is not an option as floor already laid.

We have a large kitchen /diner/family room with 6 bifold doors across the back .We bought triple glazed doors from a firm in Huddersfield with heat efficiency of below 1Anything above that according to our builder is not very good thermal efficiency .We upgraded our radiators.We also fitted thermal blinds on every bi folds .They are designed like a honeycomb innard to keep the heat in and do seem to work .We also have a very quiet dishwasher Miele I think can watch Tv with it on with no issues.our Velux blinds are also thermal and remote control .Nice and cosy .

Re noise. We have an open plan kitchen opening out to an extension with a dining and seating area. The washing machine and tumble drier are in a seperate utility room. The dish washer is in the kitchen and is pretty quiet so doesn't really impact us. The extractor fan over the hob is a different matter, even on the lowest setting it is really quite loud!
Don't know whether its just that particular make (CBA I think) or they're all like that.

The other noise we notice from the kitchen when someone is cooking is stir frying! When my sons at home and stir frying away like mad, with the extractor fan on, it really is quite intrusive if you're trying to watch the tv or have a quiet moment with a book.

We’ve got a calor gas heater, one that takes a blue gas bottle and it’s gives out an amazing amount of heat for hardly any cost. They look much better now than the original ones…

Thanks thats a good option, a calorie gas heater hadn’t crossed my mind. Which one do you have, roughly how long would the bottle last if used everyday?

Our kitchen diner - part extension, part original 1920s house but with a new floor slab and most of the wall replaced with bifolds - is the warmest room in the house. Mind you, that might say more about the rest of the house (original sash windows, open chimneys, uninsulated suspended floors...) than it does about the kitchen diner!