I hate asking the question, but here goes... it's about SIZE

[jason61c]

I'd love to, I really wood (get it? )

BIG obstacles however... blowing £15-20k in one hit is out of the question, and lack of space is the other issue. To really get the efficiency out of one I get the feeling that buying in bulk is pretty much required, that is not an option.

The common concensus during my initial investigations on eco technologies was that if there's mains gas, there'd be little point fitting biomass. Oil or LPG, fair enough.

When we retire and move to the country, I'm sure biomass will make an entry into our lives, along with wind turbines and a field of solar panels

The rooms without dimensions are effectively unheated (or rather they are for frost protection only but they're not living rooms... laundry / workshop type rooms)

I think you'd be looking at 15k, 20k in your pocket.... That'd help pay for any works on the house

 

[SilentDancer]

Out of curiosity... I managed to get a quick look at the glowworm that's currently powering the system.

30kW output ... it's a Hideaway FF, and it's heating more rooms than the intended new system would be.

That would say to me that there could be an option to go higher rated combi?(which would be the ideal)

If you install a combi with multiple bathrooms it is highly likely you will not have enough hot water in the winter particularly if you try to run two showers at the same time.

Instead install a heat only boiler with an unvented cylinder. You will then have more than enough water for multiple showers. Modern cylinders are very well insulated so the heat loss from them is miniscule. You could install a twin coil one allowing you to add solar at a later date.

Ignore the tool pushing biomass. On mains gas you will not save per kWh and they are notoriously unreliable.

 

[jason61c]

Out of curiosity... I managed to get a quick look at the glowworm that's currently powering the system.

30kW output ... it's a Hideaway FF, and it's heating more rooms than the intended new system would be.

That would say to me that there could be an option to go higher rated combi?(which would be the ideal)

If you install a combi with multiple bathrooms it is highly likely you will not have enough hot water in the winter particularly if you try to run two showers at the same time.

Instead install a heat only boiler with an unvented cylinder. You will then have more than enough water for multiple showers. Modern cylinders are very well insulated so the heat loss from them is miniscule. You could install a twin coil one allowing you to add solar at a later date.

Ignore the tool pushing biomass. On mains gas you will not save per kWh and they are notoriously unreliable.

You are funny. Its not about saving anything, its about the money you get given

 

[funkydiver]

Sooooo.... a plumber (very nice chap and recommended) came round on Saturday evening to survey the place.

It's his opinion that either a high output combi (40kW) OR system boiler will achieve the same outcome, with the exception of one needing a tank and the other ... not so much.

Wife is against the whole storage tank idea, regardless of recharge rates.

So, just to be on the safe side, I'm going to try and work out the heat loss / requirements for each room.

Some assumptions.

Sufficient Insulation - yes (in the medium term)
Double Glazing - Yes
Draft proofing - oodles

Would the following figures seem to be about where I'm looking in terms of calculating overall Btu/h heat loss per cubic metre?

Room Type Normal North
Dining / Lounge 160 185
Bed / Bath 130 150
Others 95 110

 

[funkydiver]

And using the above, I chucked together a quick spreadsheet for the main rooms....

Does this look to be about right?

Untitled

• funkydiver
• 17 Nov 2014
• 1

 

[Agile]

Since 1980 the UK has been metricated and heat is measured in kW.

Better to use the whole house method.

Or just 0.14 kW per sq metre.

Tony

 

[D_Hailsham]

Would the following figures seem to be about where I'm looking in terms of calculating overall Btu/h heat loss per cubic metre?

Room Type Normal North
Dining / Lounge 160 185
Bed / Bath 130 150
Others 95 110

1. kW are now standard. Why do you work in BTU?

2. Where did you get the above numbers from?

3. What temperatures are assumed?

3. Heat doesn't just vary with volume. The above numbers only assume a difference in temperature and orientation.

 

[jason61c]

your family room is the size of a new build 3 bed semi

 

[funkydiver]

Since 1980 the UK has been metricated and heat is measured in kW.

A fair and valid point... it's a little more difficult buying rads in Watts though..

For example... this is the output from the product description when searching "3500 watt radiator" in Google.

has an outstanding heat output of 1,026 Watts (3,502 BTUs) and is supplied with an industry leading 15 YEAR WARRANTY.

I checked on a few website calculators for the rounded figures. MrHeating, B&Q, TradePlumbing as well as a couple of US based ones looking at target output - more importantly temperature / comfort levels. I have gone into this with eyes open, I'm a clever lad you know, but science doesn't necessarily beat experience

I will agree that there are a lot of variables in place, at least this gives me a starting point to work from, and beyond having a whole house survey, presumably the sum of the whole can be broken down into it's component parts. Hence the route I took here.

Anyhoo, a quick addition to my spreadsheet... I present you with an amended output.

Just to be clear, there does appear to be random rounding / inconsistency, but the numbers are right in terms of the totals. No point in getting bogged down with decimal point numbers.

Untitled

• funkydiver
• 17 Nov 2014
• 1

 

[funkydiver]

your family room is the size of a new build 3 bed semi

Yup. My mates bungalow would fit inside it... and he has a 34kW boiler, hah

 

[D_Hailsham]

I checked on a few website calculators for the rounded figures. MrHeating, B&Q, TradePlumbing

Now use this Radiator Calculator

Anyhoo, a quick addition to my spreadsheet... I present you with an amended output.

Anyone can divide by 3.412. But the figures are still as meaningless as the "multipliers" you have used.

160 BTU/m³ is approx 47W/m³. Presumably this assumes a room temp of 21C when it is -1C outside. Making the same assumption, the watts/m³ for the rooms in my house varies between 15W/m³ and 35W/m³.

 

[funkydiver]

Anyone can indeed manipulate numbers to mean pretty much anything, I wholeheartedly agree. I suppose in some respects I am looking at a worst case scenario, and used numbers to reflect this.

My aim is purely to make an educated choice around, at this point, a boiler setup that is going to cope admirably, but at the same time not be over powered / excessive.

I have the benefit of the knowledge that although the place was previously used as a care home and the heating was on pretty much constantly, the 33kW boiler coped with providing a consistent heat output to keep the place comfortable. But then it was on pretty miuch all day every day, so cooling wasn't so much of an issue.

Thank you for the link, I can at least add in some variables I haven't seen on other calculators.

 

[Dan Robinson]

Tired to reply to your PM, but your profile won't accept it.


You need to allow messages from random punters, or add me as a friend.

 

[Agile]

You don't buy rads by their power output.

You buy them by the size, chosen by height to fit under windows, length to fit along wall and then see if power output suits the power needed.

Double panels are about 1.8 times that of a single.

Long rads spread the heat more evenly and look better and don't intrude into the room so much.

Tony

 

[Dan Robinson]

You don't buy rads by their power output.

You buy them by the size, chosen by height to fit under windows, length to fit along wall and then see if power output suits the power needed.

.......

Long rads spread the heat more evenly and look better and don't intrude into the room so much.

Tony