house renovation

[finisterre]

Is it externally rendered?

A mate (building lecturer) has the hots for external cladding using 3 inches of kingspan, ply, cement render.

We keep our bills down as I have dry lined all our external walls with 50mm of kingspan, the roof has 100mm, the floors 75mm. Surprisingly it was the floors that seemed to make the most difference.

The morso wood burner was also vastly better than an open fire.

I did a calculation, 6mm of kingspan is equivalent to our 800mm thick rubble walls.

The south facing story and a half conservatory catches a lot of heat too.

 

[SilverSaloon]

no rendering. We want to get a wood burner as we will have ample wood to burn

 

[del320]

Making wind and watertight, insulating and draught-proofing goes without saying.

Scottish Environment Protection Agency - SEPA - required all septic tanks to be registered after mid 2009. Existing owners were not required to take any action then, but when a property sale takes place, the vendor must complete registration at their expense (c£200 iirc) Ensure your solicitor covers this.

Make sure your deeds detail the location of the tank and if it is shared, apportionment of maintenance costs. Even then, the wise will lever up the lid to look inside whilst somebody flushes the bog. Bath, basins, surface and other grey water should generally drain to a soakaway.

Check these things out scrupulously as you don't ever want to be down there with it going over your wellies.

 

[Piff]

For sewage treatment, I quite like these WPL Diamond
Easy to install, cheaper than mechanical treatment plants and no moving parts in the mucky stuff!

 

[Piff]

Most important to insulate well/draft proof.
I would then look carefully at the feed in tarrif for solar pv and the new renewable heat incentive for heating.
Have you looked at (and have space for) a wood pellet (biomass) boiler? One of these feeding a thermal store would be a good way of providing under floor heating & hot water.

 

[trapperjohn]

Kingspan? Does that get attached to the attic roof supports. Totally none in our gaff. Lot of fibreglass stuff between the joists though.

 

[Uncle Fester]

Have you thought about LPG in a bulk tank?
Solar panels to heat a 150 litre unvented cylinder, coupled to a combi boiler to boost hot water when solar activity is low.

SolarSmart 150 pack

unlike most other forms of DHW solar, you get to use whatever is in the tank every day, should offset the cost of the LPG somewhat.

As stated, insulation is the key, and underfloor heating is the most efficient use of your fuel.

With a good heating engineer, various fuel options can be coupled together to give you the cheapest running costs.

 

[Dieselman]

unlike most other forms of DHW solar, you get to use whatever is in the tank every day, .

What do you mean by that?

The website shows it uses flat plate collectors, which won't be very efficient in cooler climates, such as the frozen North, much better with evacuated tubes as thir efficiency stays high in cold weather.
A flat plate loses about 50% of generated heat once the differential between the panel and ambient passes 10c-20c.

 

[Uncle Fester]

even if you get 40 deg C in the tank, you get to use it as it is fed into the combi boiler to be heated to useable temp, the solar system is not as efficient as evac tube when in very sunny conditions, but works better at lower solar gain, such as UK climate.

System was designed and built in Holland, and does work very well, for instance today got 70 deg C in hot water tank by lunch time.

System shuts down if difference between tank temp and panel temp gets below 10 deg C, so you get to keep what you have.

For better explanation best to call the teck team for advice.

 

[Piff]

I thought that the two most expensive fuels for central heating are LPG and oil. Electric is up there too, although in Scotland there are some tarrifs desighned for electric boilers giving more "off peak" electricity ant various stages through the day

 

[Dieselman]

the solar system is not as efficient as evac tube when in very sunny conditions, but works better at lower solar gain, such as UK climate.

System was designed and built in Holland, and does work very well, for instance today got 70 deg C in hot water tank by lunch time.

I am very aware of how solar water systems work but don't follow you on a couple of your points.
What was your starting temperature today, how much of the cylinder was heated, was it only heated by solar, how much panel area do you have?

You would be better to measure the energy dispersed into the cylinder than talk about peak temperatures.
Today we collected 10.3Kw of heat energy into the cylinder and this month has yielded 130Kw so far.

You are the wrong way round regarding the heat losses between flat panels and evacuated tubes.
On hot sunny days a flat panel can have about the same efficiency as an evacuated tube, but as the ambient temperature reduces the evacuated tube becomes much more efficient due to heat loss from the flat panel, which effectively starts working as a radiator.

A quick check is to see how long snow stays on the panel, the longer, the more efficient the insulation is. A vacuum should lose no heat as it can't travel across a vacuum.
A flat panel system isn't going to work very well in a Scottish winter.

 

[Uncle Fester]

I thought that the two most expensive fuels for central heating are LPG and oil. Electric is up there too, although in Scotland there are some tarrifs desighned for electric boilers giving more "off peak" electricity ant various stages through the day

True, but with a good heating engineer mixing different fuel types together a good compromise can be made, for instance a wood burner with a heat exchanger fitted to the flue to generate hot water for a thermal store, with a combi boiler on LPG for back up, then a relitively economical system can be utilized.

No fuel is cheap these days unless you have a supply of free wood (ie you're a tree surgeon)
Even ground source is expensive to insatll so you have to balance out that cost over a period of years.
I think you have to go for the best availa ble options that won't break the bank, and wait for technolegy will catch up.

 

[finisterre]

Kingspan Insulation - Overview

i think urethane foam (sp?) is about four times as effective as rockwool.

 

[Dieselman]

A mate (building lecturer) has the hots for external cladding using 3 inches of kingspan, ply, cement render.

.

He is right because the heavy stone walls act as a thermal store where the heat cant escape due to the exterior insulation.

 

[Dieselman]

Kingspan Insulation - Overview

i think urethane foam (sp?) is about four times as effective as rockwool.

Rather surprisingly, it's only twice as good iirc.

 

[Uncle Fester]

"You are the wrong way round regarding the heat losses between flat panels and evacuated tubes.
On hot sunny days a flat panel can have about the same efficiency as an evacuated tube, but as the ambient temperature reduces the evacuated tube becomes much more efficient due to heat loss from the flat panel, which effectively starts working as a radiator"

the system shuts down if the difference in temp between the stored water and the panel gets to 10 deg C so the panel will not act as a rad.

You'd need to talk to thier R&D guys for the blurb on panel efficiency, give them a call and ask for Ken or Darren.

 

[finisterre]

a thermal store where the heat cant escape due to the exterior insulation.

I am beginning to feel like the straight man in our relationship.


would you like to expand on this?

0.020 W/m.K (≥ 45 mm)

 

[finisterre]

Rather surprisingly, it's only twice as good iirc.

It feels better than that.
perhaps it is aided by the way we install it

Taped joints and no bridging etc?

 

[Dieselman]

the system shuts down if the difference in temp between the stored water and the panel gets to 10 deg C so the panel will not act as a rad.

The panel will indeed act as a radiator whenever the surface of the metal plate (which is probably stainless steel) is warmer than the ambient temperature...it's how a radiator works.
Once that differential is greater than about 10c the panel will be losing efficiency rapidly. Once at 20c it's only about 50% of it's original efficiency.

The controller will indeed stop the pump so hot water isn't pumped from the cylinder, but the panel will be acting as a radiator both when pumping and when switched off. When off all the collected heat in the panel will gradually be lost.
Are you sure the differential is set to 10c, that's very high, normally about 3c would be the switch off and 10c the switch on differentials.

 

[Dieselman]

Kingspan Insulation - Overview

i think urethane foam (sp?) is about four times as effective as rockwool.

According to this Wiki page it's 3 times as good, but last time I looked through a suppliers catalogue it showed as only twice as good.

R-value (insulation) - Wikipedia, the free encyclopedia

Either way, well worth doing during a renovation.

The battening off the solid wall will help due to the air gap.