1930's Shell. What do i install?

[Deleted member 294929]

Since you are redecorating I would seriously consider fitting 50mm internal wall insulation on external wall.

Is there an external wall instalation that looks good and finishes well around windows?

 

[Mister Banks]

Personally I think you should be sizing the heating and hot water system on the requirements of the house and not on your personal needs today. Otherwise you will be wasting money on upgrades later on plus peoples circumstances can change and you don’t want to be in a position where you might have to sell a house with an under rated system installed.

 

[winston1]

Apart from not very good performance electric showers are very expensive to run. Electricity per kWh is four times, yes four times, the cost of gas. Look at the cost per kWh on your bills.

 

[RedMango]

Personally I think you should be sizing the heating and hot water system on the requirements of the house and not on your personal needs today. Otherwise you will be wasting money on upgrades later on plus peoples circumstances can change and you don’t want to be in a position where you might have to sell a house with an under rated system installed.

I will be, I've done some calculations and got a rough idea on what output I need, this is what ultimately made me disregard UFH. The house is currently empty so bit hard to judge it's requirements however when all completed it will still only have 1 bath/shower combo maybe separate. I'm not sure why I'd consider a unvented system over a combi all the time a combi can supply enough hot water. I've done all the online calculators and "boiler recommends" they all come back with combi. If it turns out I need more hot water later on I can rip it out and put a veissman 111 In, that will give me a bit extra for minimal work and sub £2k. If I need even more then so be it.

An electric shower load on my electric is not really a concern, I have a 5 min shower a day at most. Coupled with the fact I plan to have a large solar array and battery storage I don't plan on my electric bill being too much.

 

[RedMango]

Apart from not very good performance electric showers are very expensive to run. Electricity per kWh is four times, yes four times, the cost of gas. Look at the cost per kWh on your bills.

I think we are getting a bit fixed on me maybe putting in an electric shower in an ensuite that I probably won't have built for another 5+ years

 

[foxhole]

Insulate it to with an inch of its life , heating cost are only going to rise and alternatives to gas like heat pumps etc only work in extremely well insulated homes.

 

[BarryCambs]

If you have good water pressure, I'm not sure why you wouldn't go with a combi. I'm on my 3rd 1930 house renovation. 1st already had a new gravity tank system, which worked well enough, but the tank took up a lot of room. Second, no heating and put in a Vaillant Combi. Just so easy to fit without a tank! 3 bed semi and we had 3 babies while we were there, so baths every night. Never regreted the choice of a combi. Now we are in a large 5 bed house. The old boiler had died, so I took out all the tank work and converted it to combi. The kids are all old enough that they have showers now and the Vaillant 835 shows it's running at about 1/3 capacity while the showers being used. I' sure it would happily run two, but the water supply to the house isn't up to that.

As said above, I'd put the money into insulating it properly

 

[RedMango]

If you have good water pressure, I'm not sure why you wouldn't go with a combi. I'm on my 3rd 1930 house renovation. 1st already had a new gravity tank system, which worked well enough, but the tank took up a lot of room. Second, no heating and put in a Vaillant Combi. Just so easy to fit without a tank! 3 bed semi and we had 3 babies while we were there, so baths every night. Never regreted the choice of a combi. Now we are in a large 5 bed house. The old boiler had died, so I took out all the tank work and converted it to combi. The kids are all old enough that they have showers now and the Vaillant 835 shows it's running at about 1/3 capacity while the showers being used. I' sure it would happily run two, but the water supply to the house isn't up to that.

As said above, I'd put the money into insulating it properly

Sounds good to me, how do you find the vaillants? I've been trying to compare the veissman and bosch

 

[BarryCambs]

If you ask 10 different people, you'll get 10 different answers, but the first vaillant is still fine after 14 years according to the guy who bought the house. Dad's Bosch is just as goof though. The new house I've fitted a Green IQ rather than standard. The gas bills are nice and low, but in the cold weather when the weather compensator brings the heating temperature right up, the hot water is too hot for the first minute of running tap.

We are just fitting a second shower room. Bottom line is, not many houses will have the water pressure to run 2 showers at once, so fitting an electric one won't really help. A pressurised cylinder will be the same - it can only give out the same as an incoming supply. I'd rather people just got used to not using the showers at the same time rather than going back to a gravity system and I can promise you, if you have young kids in the house, angsting over the ultimate hot water supply system will be the least of your worries! I'd stick in a decent combi, forget it and concentrate on the insulation, especially if it's solid walls.

 

[dilalio]

I'm pretty sure you won't have this done by @June 15th this year.
At that point PartL of building regs are to change.
Any new gas powered system install which involves complete replumb and rads MUST be designed for a flow temp of equal to or less than 55°, thus an MWT of 45°, resulting in an MWT-AT of 25°.
Pipework and (more importantly) rad sizes will need to be increased to meet the heat loss requirements of each room within the property.

An simple example would be that a K21 rad would need to be upsized to a K22, roughly speaking.

 

[RedMango]

I'm pretty sure you won't have this done by @June 15th this year.
At that point PartL of building regs are to change.
Any new gas powered system install which involves complete replumb and rads MUST be designed for a flow temp of equal to or less than 55°, thus an MWT of 45°, resulting in an MWT-AT of 25°.
Pipework and (more importantly) rad sizes will need to be increased to meet the heat loss requirements of each room within the property.

An simple example would be that a K21 rad would need to be upsized to a K22, roughly speaking.

What does that mean in layman's terms? I need to get bigger rads? We would have been going for daily large decent ones regardless?

Also stupid question inbound but how does the whole building regs work? In my mind, if I get the keys to my house, go in and fit whatever I want then who knows it is or isn't to regs?

 

[dilalio]

@RedMango,

Yes it means rads larger than current heat loss calcs would prescribe.

Radiator sizing apps, catalogues and charts currently use a 50° deltaT (difference in temperature) between the desired room temperature and the mean (average) water temperature in the radiator.

This is based on gas boiler having a flow temp of 80° and a return temp of 60° (20°deltaT).

1. water entering rad = 80°
2. Leaving rad = 60°
3. Mean water temp in rad = 70°
4. Desired room temp = 20°
5. DeltaT between 3 & 4 above = 50°

To make better use of condensing boilers and reduce energy wastage / burning of gas, green issues, through partL building regs, aims to lower the flow temps of boilers to 55° with a return temp of 35°.

Using the method above (1-5) gives a result thus...
5. DeltaT = 25°
Which is half of what radiators are currently designed and sold at.
In simple terms you do a heat loss calc for a room, choose a rad that has the appropriate KW output for that room (which will be based on a deltaT of 50°) then you double the KW output and make a new selection from the catalogue based on that, to see what dimensions/type of rad will deliver that output, thus heating the space to the desired temp using the lower flow temp of 55°.

As for whether you need to comply or not, it would be in your best interest to do so now, during this opportunity of a new install, because in @10 years time (sooner if law changes) you will need a new heat source in your forever home and by then, it's pretty certain you will not be able to achieve flow temps of more than 55°, thus rendering your heating system insufficient.

 

[RedMango]

@RedMango,

Yes it means rads larger than current heat loss calcs would prescribe.

Radiator sizing apps, catalogues and charts currently use a 50° deltaT (difference in temperature) between the desired room temperature and the mean (average) water temperature in the radiator.

This is based on gas boiler having a flow temp of 80° and a return temp of 60° (20°deltaT).

1. water entering rad = 80°
2. Leaving rad = 60°
3. Mean water temp in rad = 70°
4. Desired room temp = 20°
5. DeltaT between 3 & 4 above = 50°

To make better use of condensing boilers and reduce energy wastage / burning of gas, green issues, through partL building regs, aims to lower the flow temps of boilers to 55° with a return temp of 35°.

Using the method above (1-5) gives a result thus...
5. DeltaT = 25°
Which is half of what radiators are currently designed and sold at.
In simple terms you do a heat loss calc for a room, choose a rad that has the appropriate KW output for that room (which will be based on a deltaT of 50°) then you double the KW output and make a new selection from the catalogue based on that, to see what dimensions/type of rad will deliver that output, thus heating the space to the desired temp using the lower flow temp of 55°.

As for whether you need to comply or not, it would be in your best interest to do so now, during this opportunity of a new install, because in @10 years time (sooner if law changes) you will need a new heat source in your forever home and by then, it's pretty certain you will not be able to achieve flow temps of more than 55°, thus rendering your heating system insufficient.

Perfectly explained, thanks for taking the time cheers. I'll definitely bare that in mind then as your right I probably won't be installing till earliest November at a guess.

 

[Diver Fred]

@RedMango,

Yes it means rads larger than current heat loss calcs would prescribe.

Radiator sizing apps, catalogues and charts currently use a 50° deltaT (difference in temperature) between the desired room temperature and the mean (average) water temperature in the radiator.

This is based on gas boiler having a flow temp of 80° and a return temp of 60° (20°deltaT).

1. water entering rad = 80°
2. Leaving rad = 60°
3. Mean water temp in rad = 70°
4. Desired room temp = 20°
5. DeltaT between 3 & 4 above = 50°

To make better use of condensing boilers and reduce energy wastage / burning of gas, green issues, through partL building regs, aims to lower the flow temps of boilers to 55° with a return temp of 35°.

Using the method above (1-5) gives a result thus...
5. DeltaT = 25°
Which is half of what radiators are currently designed and sold at.
In simple terms you do a heat loss calc for a room, choose a rad that has the appropriate KW output for that room (which will be based on a deltaT of 50°) then you double the KW output and make a new selection from the catalogue based on that, to see what dimensions/type of rad will deliver that output, thus heating the space to the desired temp using the lower flow temp of 55°.

As for whether you need to comply or not, it would be in your best interest to do so now, during this opportunity of a new install, because in @10 years time (sooner if law changes) you will need a new heat source in your forever home and by then, it's pretty certain you will not be able to achieve flow temps of more than 55°, thus rendering your heating system insufficient.

I other words - Plan your rad's to be heated by a Heat Pump which runs at a lower temp.

 

[winston1]

Sounds good to me, how do you find the vaillants? I've been trying to compare the veissman and bosch

Think about Glow Worm. They are the same company as Valliant but cheaper.