Green Building Forum - Heating and cooling Tue, 19 Dec 2023 06:19:25 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 How to "side" a reclaimed DG unit http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13975 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13975 Tue, 19 Jan 2016 11:52:02 +0000 MikeRumney The gap between DG and the outer is about 300mm, which is the thickness of the roof, and it has pipework in place to circulate air through it should condensation strike!
Here's the rub:
Whereas one of the two DG units being used is still in its frame, meaning we have a way of knowing which side is outward, (based on assumptions about which way French doors open)
the other one isn't.
Does anyone know of markings to look for? or a method of testing??]]> Daikin Altherma Hybrid split heat pumps.. http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13961 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13961 Wed, 13 Jan 2016 16:18:57 +0000 cjard
SInce finding this out, I can't help but think it's not so much a unique selling point after all - why bother integrating it into the indoor unit when the unit could simply be made smaller, keep the intelligent control of ashp/boiler mode and have a switched/voltfree connection to command a separate boiler?]]> Self-regulating UFH: how to control mean water temperature of flow and return http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12266 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12266 Thu, 26 Jun 2014 23:25:57 +0100 Shevek http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=10244&page=1

But how exactly do we do this? Do we simply set the supply temperature using our boiler control (to give us the right room temperature) and the leave it? Or is control of the mean flow and return more complicated than this?

We're fitting an Atag 325ECX, which has its own pump and controls for supply temperature. Some text from installation manual below.

The boiler has a self-adjusting and self-protecting control system for the load. This involves checking the temperature difference between the supply and return water. Table 3 shows the water displacement a circulation pump can deliver for a particular installation resistance.

A325ECX (from Table 3)
Pump type = UP 15-60
Water flow rate at delta-T 20 degrees = 18 litres/min
Permissible installation resistance = 20 kPa / 200 mbar

If the installation resistance is higher than the value stated, the control system will adjust the load until a temperature difference between supply and return water is reached that is acceptable for the control system.
When the temperature difference still remains too high the boiler will switch itself off and wait until the high temperature differential between the flow and return water has decreased again.

The control system will, if an unacceptable temperature difference is detected, repeatedly try to establish a water flow. If this does not succeed, the boiler will block itself.


The boiler is equipped with an intelligent control system: CMS (Control Management System). Each boiler anticipates the heat demand of the heating installation or hot water demand. This will cause the boiler to tune its capacity to the installation. This means that the boiler will function longer and at a low level.
If an outside sensor is connected, the control system is able to function, depending on the weather. This means that the control system measures the outside temperature and the supply water temperature. On the basis of this information the control system calculates optimum supply water temperature required for the installation.


CH controls
With a demand from the heating controls, the boiler activates its 1 minute delay period. This is to prevent the heat exchanger from losing its heat too quickly in the event of a hot water demand. Then the pump starts and after 30 seconds the gradient control becomes active. The starting point of the gradient control is the currently existing supply temperature. A Delta-T control (25K) ensures a stable control according to heat request. If the supply temperature is below the T-set value of 20°C the boiler will immediately start.

In case of weather-dependent controls (1kOhm outside ARZ0055U sensor connected) a daily temperature is set instead of a supply temperature. Control will take place according to the heating line.

The ATAG A is equipped with boiler sensors of 10kOhm. The resistance value and corresponding temperature are shown in the accompanying table.
]]> insulating diy thermal store http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13905 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13905 Tue, 22 Dec 2015 12:28:12 +0000 johnnyh
if anyone else out there has a homemade thermal store i would like to know how you insulated yours.
mine has a wrap of glass fibre 170mm and i am trying to add a fairly well sealed polythene sheet on top of that to stop air movements.]]> Overlay ufh with thermal store? Work ok? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13953 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13953 Mon, 11 Jan 2016 23:09:23 +0000 cubbs
I'm about to order my TS and all manner of valves and pumps tomorrow from TMS in Wales. 3.5k's worth!

Will the behaviour of an overlay UFH setup work ok with the proposed TS?
With the pipes not in a screed so the floor not really holding the heat as long will that make the TS inefficient?

Excuse my inexperience of these matters

Thanks]]> First fixing- cat 5/6 needed for heating controls etc? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13926 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13926 Sat, 02 Jan 2016 15:09:50 +0000 cubbs
Are cat5 or 6 cables needed between our plant room and to ufh manifolds positions? Eg Nest heating controls etc?

What are the recommended weather compensating heating controls? To run oil boiler for starters but log burner and solar thermal in the future

Thanks]]> Bathroom room stat position? Wet UFH http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13928 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13928 Sat, 02 Jan 2016 16:47:32 +0000 cubbs
Can they go inside the bathrooms?

Or is it two single boxes? One inside and one outside room?

I'm trying to get all the donkey work done before spark is on site on Monday

Thanks]]> Extraflame or similar small wood pellet or chip boilers http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7222 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7222 Sat, 02 Apr 2011 13:43:46 +0100 Nick Parsons

Thanks.

Nick]]> Woodburner and solar with Thermal heat store – can it be altered to provide instant heat? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13600 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13600 Fri, 14 Aug 2015 16:39:06 +0100 Chrisj Heating consists of underfloor – (just put in), in 2 ground floor rooms and radiators in upstairs rooms and in bathroom extension.
A system fuelled by a woodburner supplemented by solar thermal and also electric in emergency e.g. illness.
We were quoted for an unvented system with a Dunsley boiler, solar thermal panel and a 180L thermal store with solar coil. Thermal store to be connected to DHW system and heating system.
We couldn’t afford it all so asked for the above system that was quoted but without solar panel– and still have thermal store with solar coil for when we could afford it.
When it was installed I tested running the heating system using the heat store which I heated in advance with the woodburner. The heating didn’t come on and I then found out that the company they have not connected the THS to the heating.
I tried heating the THS with the immersion heater – it doesn’t heat all the water in the tank and doesn’t provide enough hot water for a bath. The THS has a 3kw immersion heater in it.
When we raised this, the company said it was impractical to connect the THS to the heating system because the heat in the THS will very, very quickly drop and the woodburner can’t replenish heat in the THS – efficiently. (This was the first time they had mentioned this despite connection being in the quote). At one point they said it might run the heating system for 20 to 30 minutes, but the next time they said it wouldn’t work.
We wanted a system which provided the option of instant heating , even if limited (we thought through the THS) and emergency backup – through the immersion heater, but we are now left with a system which only ever provides heat when the wood boiler is burning – exactly what we wanted the THS to prevent.

Is there anything that can be changed or added to the system so that we have the option of instant heating e.g. for half an hour in the mornings and/or emergency backup if we can’t fire the woodburner e.g. if ill etc.

Is there any pointing in having a 180L heat store for DHW if it is heated just with solar thermal and excess woodboiler heat ?– I didn’t want to rely on electric for any part of the system (except in emergency) and the company are saying that you are supposed to keep the THS to temperature because if it loses all its heat, having to heat it up again is very inefficient/would use loads of fuel?
Is there a more appropriate kind of cylinder if DHW is mainly heated by wood boiler and solar?]]> Radiator and pipe sizing for heat pump http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13918 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13918 Wed, 30 Dec 2015 08:45:39 +0000 EuskalElle
In theory this is fine: in practice, steps 1 to 3 are a bit challenging for me! Can anyone point me to resources, preferably online, where I can find out how to make these calculations? After asking a local renewables energy rep to design a system, I do have wall mu values, which helps. (The rep told me that a direct boiler replacement with a 60° system would be just fine. I believe not: at 60° I doubt whether it would either have heated the house, saved any energy cost or reduced the carbon footprint)

The system I'm looking at is air to water: I live in the SW of France so this is, I believe, a practical option with the new generation auto-de-icing pumps.]]> Ecocent gone bump? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13902 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13902 Mon, 21 Dec 2015 06:25:47 +0000 camillitech
Any news chaps?]]> Mounding a UFH manifold the wrong way up? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13876 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13876 Wed, 09 Dec 2015 22:04:25 +0000 ringi E.g. will all the flow meters, activators etc work when unsidedown?]]> Help me understand UFH actuators… http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13900 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13900 Sat, 19 Dec 2015 00:35:26 +0000 ringi
I know that there are 3 types, 240v, 12v (or 24v) and 0-10v proportional.

Firstly I have seen that at least some actuators take 3 minutes to open when they are powered. How does such a slow response allow a TPI thermostat to work, or any thermostat to keep the temperature constant in a room?

How do I control a proportional actuator, it seems that standard thermostats don’t support them?

Given a choose I would like a fully wired system, as I don't trust wireless to remain pain free and the building is at a stage where putting wires in is easy.]]> 'Connecting' log burner flue to (MHVR)...just a thought! http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13879 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13879 Fri, 11 Dec 2015 20:23:07 +0000 kentishgreen
- Bungalow renovation with insulation where I can (floors, EWI, ceiling) and 3G windows.
- I'm not going to end up with an airtight house though and may opt for log burner.

Plan to live in the house for a year and experience a winter (2017 hopefully) to see how the MHVR and UFH perform, but I may also add an air tight log burner (with own air supply) into the mix (wood is onsite and I have a regular supply). But rather than losing a lot of that heat in the flue, surely there must be a way to use up some of that heat b4 it escapes into the atmosphere by way of connecting it to the heat exchanger of the MHVR? Not talking about mixing /exposing the hot air with the incoming air duct, but by running the flue parallel to incoming cold duct of the MHVR. I know the flue will go up vertically obviously but the incoming air duct could possibly also have a portion of it vertically before it goes into the MHVR unit.

MHVR duct would have to be metal obviously and probably no point having an insulated flue pipe at the 'heat exchange' point. Would have have temp guage fitted to ensure the temps stay within a 'safe range' to ensure maximum heat intake is not exceeded as the air hits the MHVR unit as well as to ensure things don't get too hot in the loft (smoke/heat detector units, fire extinguisher!!).

Most MHVR units appear a bit plasticy where the heat exchange takes place, so would need to ensure that the incoming heat is not too high, or get hold of an MHVR unit that has a metal matrix.

Perhaps there's something on the market already that does this? Or maybe I just need to add this to my retirement list of things to try out (okay, in the shed, not the house!). I recall someone on here doing their own DIY MHVR unit?

And no doubt HETAS would not approve of any of this!

No, I haven't had a drop yet! But just wanted someone to blast this idea out of my head as I should be having my mind trained on other pressing matters like windows and floor insulation!]]> Using MPPT - PV panels direct to Immersion http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13882 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13882 Sun, 13 Dec 2015 18:14:51 +0000 johnuready
Direct connect with no battery connected.]]> Continuing underfloor heating up walls http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13867 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13867 Fri, 04 Dec 2015 13:01:09 +0000 Shevek
* in order to increase the amount of radiant heating the body receives and lower air temperature.]]> DHW - how? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13841 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13841 Thu, 26 Nov 2015 07:49:28 +0000 maxelaine
We'll be having solar PV, which could dump excess into the DHW on long & sunny days, and during daylight.

We'll also have bottled gas for cooking (no mains gas, and just like cooking on gas).

How do we lift the DHW from the 40c the ASHP would provide to the 55c (occasional 60c for legionnaires) on short days / in the dark?

Can you get a propane-fuelled combi boiler that accepts variably-warm water input?

Should we just have another immersion, powered by the grid?

Going off the idea of an Ecocent, which was plan A.]]> Quick accurate portable temperature sensor http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13863 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13863 Thu, 03 Dec 2015 07:22:15 +0000 MonsterMonster
I bought this ...

http://www.screwfix.com/p/philex-83002r-s-digital-multimeter-with-temperature-probe/88381

but found it too slow and does not tally up with any other type of thermometer\gauge e.g Laddomat. Also, the thermistor probe is a bit delicate.

I've also got one of those laser\infra-red point and shoot pistol thermometer but only works on larger dark matt easily accessible areas such as the flue fan box.

Thanks for your suggestions.]]> How does your thermal store perform and how do you measure it? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13856 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13856 Mon, 30 Nov 2015 13:47:34 +0000 MonsterMonster
The store is connected to an Eco Angus Orligno 200 40KW log gasification boiler using Laddomat 21-60, Laddomat Thermomatic CC set at 60c output to a 90KW PHE, over 13m of Uponor district heating from boiler shed to house with 13 rads, 220l direct DHW tank, closed circuits, 33,000KWhrs per year demand. The store has a single return point at the bottom.

I can fully charge the store to 82c top to bottom after a 92c batch burn (getting higher is difficult). The store has two analogue temperature gauges top and bottom. After a typical evening of heating at 19c the store will deplete to 60c\45c top\bottom and settle at 55c\49c if pushed to a second day.

Our DHW tank has on occassion heated the bottom of the store by way of high return if DHW stat is higher than flow from PHE approaching store depletion (can raise bottom of store by 2c). This has not been solved yet.

I have a feeling that 49c depletion at the bottom of the store is rather high.

So how does your store perform temperature and duration wise? Any details of your setup would be much appreciated.

Thanks
Stuart]]> ekoster 2 settings http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13850 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13850 Fri, 27 Nov 2015 16:45:32 +0000 johnnyh
Quite new to this 40kw Orligno 200 that i've got and have been playing with the settings on the controller which is an Ekoster 2. The manual, such as it is, suggests putting the laddomat pump on at 65 degrees which i find never lets the boiler get above 75 although it holds pretty steady at that temp with the pump running continuously. If i want to get the store up to 85 i have to set the 'pump on' parameter to 85 or above but then it (the boiler) tends to cycle between 90 (or even 91) and 79 degrees.
What happens is the pump switches on at 85 but the boiler continues to heat up for a few minutes. Then as the heat is drawn away it cools down but the pump keeps runnnng down to 80 and when it switches off the temp decrease continues for another minute or two before it finally climbs back up to repeat the whole cycle.

The pump hysteresis is 5 degrees which seems too much. Does anyone know if i can change this or is it normal behaviour for a log gasifier?

Thanks in advance for any advice you may have.]]> First floor UFH - is it necessary? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13853 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13853 Sun, 29 Nov 2015 10:53:04 +0000 maxelaine
So, in a 90sqm floor area house, first floor lounge, open plan on both floors, stairs opening into lounge, very well insulated ( yearly space heating reqmnt about 2,500kWh, according to the SAP), with MVHR, do we need UFH on the first floor?

Our designer says she's not a heating engineer. Her recommended heating engineer says we do, "without it, when the temp is below 0C, the MVHR will be constantly cooling the 1st floor and heat migration from the GF will be inadequate", which I don't understand.]]> CTC EcoZenith. Any good? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13845 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13845 Fri, 27 Nov 2015 01:04:47 +0000 cubbs
Looks state of the art, but expensive although i can get these with my account at Plumb Centre..

Anyone fitted these? Opinions please?

Thanks

Billy]]> five inch flue connected to stove with 6 inch outlet http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13836 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13836 Tue, 24 Nov 2015 16:16:07 +0000 jwd Help...
Cheers
Jw]]> Soft starter for ASHP http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13824 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13824 Sat, 21 Nov 2015 11:00:20 +0000 Chris P Bacon
The unit ticks most of the boxes for me, including being from a big name manufacturer so hopefully will be reliable in the future.

The only problem is that the smallest unit they do is 7.5kW, it's an invertor so goes down to a minimum output of 2kW so whilst there shouldn't be a problem with oversizing it's a single phase unit with a rated maximum start current of 19A and a maximum running current of 13A and we are on a 3 phase supply which is fused at 16A on each phase.

I've asked them if they can supply the unit with a 5kW outside unit which would have a start current below 16A but just got a flippant reply saying that last winter was very mild! *rolls eyes*

If the 7.5kW unit is my only option does anyone know if it is possible to use a soft starter to bring the start current down from 19A to under 16A or will this conflict with any of the electronics in the heat pump? (I have of course asked the company but have so far not had a response.)

I can move to a 25A supply but there is a substantial increase in our standing charge so I would obviously rather not.]]> sizing an ASHP http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13816 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13816 Thu, 19 Nov 2015 07:44:02 +0000 maxelaine
We've had one proposal (Earth Save Products) who are recommending a 4 to 12 Kw ASHP, and another, from Ice Energy, recommending a 5Kw (max) ASHP.

How do I begin to make sense of this?]]> Our new house. Blank canvas. Opinions on these options please(Walltherm) http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13827 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13827 Sat, 21 Nov 2015 20:25:56 +0000 cubbs
I'm a plumber/heating engineer on the Isle of Man and a newbie to the renewables side of things. So please bare with me.

It's a 70's two storey house. Cavity walls with pumped in loose rock wool insulation done in 1981. Loft has 300mm of knauf insulation. First floor joists have now 160mm knauf.

Downstairs is uninsulated concrete with 50mm screed approx 120m2
Upstairs approx 80m2

1. My plan is to use an overlay ufh system downstairs over a 6mm superfoil insulation
Overlay underfloor heating upstairs too over the chipboard if that is wise?
Will add a separate circuit of 2 heated towel rails.

2. I'm very keen on going for a thermal store but undecided on brands? Possibly Galu, Akvaterm or Solfex. Unsure on size? There are Five of us in our family. 3 daughters!


3. I will hopefully go for solar panels in the spring. Again what's the recommended m2 of tubes? If these produce too much heat for a thermal store? Then is it an idea to somehow trigger the pump to circulate heat to heated towel rails circuit?

4. We like the look of the Walltherm Zebru. This will be connected to thermal store along with an existing oil fired boiler. Are the Zebru fires as efficient and does the flame look as good as in their videos?

5. Am waiting on a quote for a Windhager WinFire decorative looking pellet boiler. Any good? This or the Walltherm would be our main fire in an open plan family room/kitchen.

All suggestions and ideas will be of great help

Thanks.]]> RHI Non-Domestic http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13825 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13825 Sat, 21 Nov 2015 14:28:12 +0000 mitchino
He's been banging on to us that it's an amazing opportunity, he claims that his initial investment of £40,000 will be recouped quickly, and he expects £200,000 back over the 20 years of the scheme. He say all the local farmers are having similar systems installed, and are being encouraged by the installers to buy a bigger system than they need, and to burn the extra fuel, so they can claim more cash.

He also says you only need an outhouse used for business to get on the scheme

Our property would qualify, as I run a business from a large studio near our house. I currently heat the house with oil (cheap at the moment) and the studio with electricity.

So I'm wondering, is this a 'no brainer'?]]> Water flow rate query.. http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13806 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13806 Sun, 15 Nov 2015 22:44:47 +0000 cjard
The adapters I find have a brass insert that goes inside the tube. The wall is thick and ultimately this means that at either end of a 16mm outer diameter pipe is a pipe insert that has an internal diameter of circa 6mm

Speedfit pipe has a 15mm outer diameter and also requires inserts in the ends. These inserts are more like 10mm in their inner diameter


What would give a better flow rate over X metres? 16mm o/d pipe plus two inserts at 6mm i/d, or a 15mm pipe with two 10mm I/d inserts


Related is a query over whether a UFH manifold port can supply at the rate of 9litres/minute. I like he idea of just whacking another UFH manifold on the wall and then running a pipe to every point for two reasons.. One that I have all the stuff already and the other each pipe his has just 2 joints so if a leak occurs it's unlikely to be inaccessible]]> Thermal mass - using chimney breast http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13712 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13712 Sun, 11 Oct 2015 04:01:07 +0100 Yanntoe Just built a chimney and chimney breast in our new timber framed extension. This will house a wood burning cooker/range and so far consists of 2 block piers supporting a cast concrete slab which supports the new chimney. Between the slab and the ceiling there is around 2 cubic metres of space which we had intended to build up in stud to form a void into which a high level cupboard could be built.
However, looking at this I wonder whether it might be better use blocks and fill the space so that it can act as a significant thermal store. This would gain heat all day from the fire in cooler months and release heat over night reducing the need to have the fire ticking over all night.

So, my question is, does this make sense and should I add as much blockwork as possible above the fire or maybe add a block wall and leave the centre hollow for cupboard space?

Suggestions welcomed.
Thanks
Ian]]> UFH Issues http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13795 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13795 Wed, 11 Nov 2015 08:23:00 +0000 Victorianeco
Struggling to get past 18c in the room....

Heat loss calcs done correctly, what is the most likely issue?]]> Insulating base of copper cylinder http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13754 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13754 Tue, 27 Oct 2015 07:40:44 +0000 Miked2714 Oras 4200 mixing valve on Akvaterm Solar plus http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13758 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13758 Wed, 28 Oct 2015 06:50:08 +0000 pgrbff Radiator Pipe and UFH Manifold Question http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13737 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13737 Wed, 21 Oct 2015 17:34:07 +0100 Victorianeco
Hep20 bends are bulky and unsightly.

Will there be much issue with dropping to 10mm pipe about 50cm away from the rad or am I better off switching to 15mm copper?

Also, if I were to run two rads off my UFH manifold using zone stats rather than TRV's is there a maximum distance for the pipework? My initial thinking is 6m flow and 6m return would be a non issue in the grand scheme of things considering 100m max runs for UFH?

Or am I better running off the 22mm CH pipework with 3m drops and use TRV's?]]> Clanger, but how much? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13752 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13752 Mon, 26 Oct 2015 07:52:19 +0000 cjard
I have a screed slab of approx 120 sqm and this is in a semi with the same on the other side. It sits on 175mm of pir and around the external perimeter I brought the wall PIR insulation down the wall to touch the floor PIR, isolating the heated screed from the external wall

In this crude text diagram that is a side section through, T is timber, N is insulation, B is blockwork (usually thermalite, occasionally dense concrete for load bearing points), S is screed and G is the ground

TN
TNSSSSSSSS
BNNNNNNN
GGGGGGG

Sometimes there are also small walls internally to the area of the slab that are load bearing and these are timber sitting on a block upstand. My concern is that i forgot to add a small 25mm strip of PIR between the screed and these block upstands, so all there is separating the screed from being in thermal contact with the block (that sits on the foundations) is a gap of probably 15-20mm created by the edging strip (a polystyrene-esque foam)

Another crude "drawing", the I being the edging strip:

T
TISSSSSSS
BNNNNNN
GGGGGG

I reckon there's approx 20m, maybe 25m of screed edge face (on a 50mm thick screed though at the edges this probably lessens due to the curve on the edging strip) where the screed is "more exposed" to block that is in thermal contact with the ground. It's still thermally broken, but not by the designed 25mm of PIR

My question is, is this such a calamity that I should look at getting a cutter out (bearing in mind this risks damage to the UFH) and cut 5-10mm off the edge of the screed all around this perimeter, and fit 25mm of PIR in place of the current edging strip?
If the financial impact of just letting more heat escape from this joint, over the time I'll keep the house, is less than the few days plus materials it'll take to change it then I'll just leave it.. (I have far more pressing things to attend to)

I'm assuming that, in terms of heat paths, the external walls that are well insulated are the most important, and that eventually these internals walls would establish their own heat gradient down to the ground below and would experience relatively lower heat loss.]]> Oops forgot to turn off summer bypass http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13735 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13735 Wed, 21 Oct 2015 11:54:33 +0100 tony
Lots are turning their heating on we just turned our outdoor cold air ventilation fans off and started recovering exhaust heat.]]> Heat pump pricing query http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13724 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13724 Sat, 17 Oct 2015 20:28:33 +0100 cjard
Ok, so most manufacturers are knocking at 12-16 kW pumps at around 4 to 5 k, why is the samsung half that?]]> recommissioning a solid fuel rayburn and boiler http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13717 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13717 Tue, 13 Oct 2015 13:54:13 +0100 dgd17
we have had it disconnected from the central heating when a new heating system was put in last year under a grant scheme. i would like to convert it back to solid fuel and run it as a woodburner (we have our own supply of wood)

i believe the boiler is still ok. is there a relatively simple bit of plumbing can be done to run a radiator or two, or some hot water from the boiler? or is it easier to decomission the boiler? i'm not sure how this is done? i've read about filling them sand, but i have no idea how one would actually do this? the rayburn is pretty much set in place and there is no easy access to the sides or rear or the rayburn.]]> ASHP recommendations and top up DHW http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13715 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13715 Mon, 12 Oct 2015 20:15:39 +0100 Greenfish
Been through our first heating season (while decorating so not normal occupancy) and all was OK. But was we go through warm damp autumn we are thinking of improvements....

Issues:
1) If we are away in winter, or feeling unwell, or for whatever reason don't feed the WBS the house eventually gets cold and it is quite an effort to get it warm again.

2)Inbetween times (like now) house is warm but not enough solar thermal on cloudy days, so we need to light a fire just for some DHW.

To solve 1) thinking of adding a ASHP - say 8kW Ecodan. We have space for it, and warm winters in Cornwall means it will be effective. Use will be to top up the other heat sources, especially between times. Any recommendations?

No idea how to solve 2). Some kind of inline top-up water heater would be great. Something to lift the low energy heated water a bit when needed. Any suggestions?]]> Optimum depth for GSHP collector http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13702 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13702 Tue, 06 Oct 2015 11:11:25 +0100 woodgnome Is it worth going down any deeper than 1500 with the pipework?
I'll have a 20t swing on site, so depth isnt a problem...
My instinct says to go as deep as practicable whilst I have the digger on site. The pipes will be laid in a 5ft wide trench with a pipe at each side, covered with topsoil first before backfilling.
Any benefits of going to 2m or so?
Cheers]]> Cold airing Cupboard http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13707 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13707 Wed, 07 Oct 2015 16:43:32 +0100 tony
Cold airing Cupboard – It is worth mentioning that the solar cylinder being so well insulated actually delivers net cooling to our airing cupboard during the coldest months as the bottom is colder and bigger than the top which holds water at 50C. Cold water enters at 10C or less on cold winter days. The solution is to have a 125W tubular heater on a 25C thermostat to keep the other half happy for a couple of months in the dead of winter this makes the airing cupboard useful again, It took me a while to realise why it was cold in there, kept looking for draughts, then realised it was lack of sun meaning that the cold water wasn’t warming as fast as it does the rest of the year. The heater only uses less than 20W at the worst time of the year.]]> Pipes for Solar Hot Water http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13606 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13606 Sun, 16 Aug 2015 15:32:05 +0100 Araucaria
The system was fine until about a year ago, when a small leak developed somewhere (of course) in the buried pipes. A week or so ago this became a substantial leak (I was able to put about 20 litres of water a minute into the system, which was leaking out at that rate).

The buried pipes are those twin flexible stainless steel pipes, about 3/4", with a robust insulation round it. However at the time (perhaps now too?) these expensive pipes were available only in lengths of 20m: so there are a couple of joins in both the flow and the return pipe. I'd guess one of these has failed. These special compression joints are a bit fiddly anyway, though I did pressure test both pipes before I buried them.

My question. Rather than have to dig it up again in the future, are there any substitutes for these S/S pipes, available in longer lengths?

The problem is that solar thermal systems can reach 110C or more for material lengths of time (eg after a power cut in summer!), and most plastic pipe seems to be rated up to 90C or at most 95C.]]> Should I get a Solar or non-Solar unvented cylinder? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13220 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13220 Wed, 18 Mar 2015 09:47:22 +0000 jerseyman
The dilemma I have, is that I would like to fit solar thermal panels at some stage, but the fitting of the panels, for various reasons is reliant on a planned extension At the moment the possibility of going ahead with this extension is about 50/50.

So I'm not sure whether to fit a solar cylinder of around 250 litres and have the possibility of not being able to fit the solar thermal and so have and oversized cylinder , or going with 175 non solar cylinder and finding that I can fit panels but have a compromised cylinder.

I am not sure if it is relevant, but our water here is very agressive so will be going for a Megaflo

At the moment I am minded to go for the smaller cylinder, but would be grateful for any views to clarify my thought process.]]> Connecting a boiler stove - H2 panel, laddomat, dunseley newutraliser (with a thermal store) http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13655 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13655 Thu, 10 Sep 2015 11:21:54 +0100 smudger
I've had 3 quotes all proposing different routes to connect up our (very) large wood boiler stove to our existing heating system which has only a small 6kw elec boiler running it currently (we have storage heaters as well). We have decided we definitely want a thermal store and going for one which is 500l and tall so hopefully good stratification.

So questions:

Do H2 / laddomat do the same job? My understanding is the laddomat circulates the water from the wood boiler to get it to burn efficiently and when at right temperature 'releases' the water to the thermal store. I'm unclear if the H2 panels does this as well or is it even necessary if we have a thermal store to 'combine' all the heating sources (there may or may not be solar thermal if we can get it fixed and possibly an immersun for an immersion).

Are there cheaper / better alternatives?

thanks]]> Water heater, Horizontal or Vertical? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13691 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13691 Fri, 02 Oct 2015 19:17:24 +0100 bot de paille
I want to put a 200L immersion heater in the roof space next to a soon to be bathroom in a renovation project.

From what I have read it is generally considered better to have a vertical HW tank because of the way the hot water separates from the cold.

Because of space issues it would be much better to have a horizontal tank. I would appreciate anyones advice on whether there really is a big difference in performance when using a horizontal tank.

cheers
Bot]]> Passivhaus; i don't understand this disparity? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13647 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13647 Mon, 07 Sep 2015 18:11:29 +0100 cjard
15kwh/sqm heating demand
10w/sqm heating load

I'm not sure how 10W/sqm times 24, times 365, divide 1000 comes to 87.6 kwh/sqm but the requirement for heat demand is 15kwh/sqm - why the disparity? What's the difference between heating demand and heating load?]]> Do you change your zone controls much? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13632 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13632 Thu, 27 Aug 2015 23:48:28 +0100 tehorodon
So... I'm interested in how people with zone control use it - set up to how you want it and then forget it, or is there some tweaking that goes on for time of year and other changing conditions? Is it just a matter of which rooms you want heated and not, or does the amount of sun in each room come into it?]]> My NZ ASHP system http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13628 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13628 Wed, 26 Aug 2015 10:31:55 +0100 tehorodon
I have some information to share about my underfloor hydronic system and how it performs - perhaps of some help to people who are considering their own builds - I hope to get some comment from the assembled expertise here on what I might do to maximise efficiency.

The major components I have are:
Emmeti Mirai EH 1611 DC - 3.57kW max power consumption - heating mode only
300l Sunflow hot water cylinder - heated by the Emetti to 55C and a 3kW back up element to get it to 60C for legionella protection
230m2 of 130mm thick post stressed slab insulated underneath and at vertical edges with 40mm high density polystyrene.
Pipework is Pex 12/16 laid about 50mm below the surface, arranged in 12 circuits (but all are 100% open all the time)
Nest thermostat

I also have a Vera home automation system which has sensor inputs for outside temp, inside temp, underfloor inlet manifold, underfloor outlet manifold, and set in the slab. It can control the Nest with logic around any of the sensor inputs and outside current/forecast weather conditions (that's a topic by itself probably).

I am in New Zealand - north of Wellington and more moderate winter temperatures than most of you would experience. Temperatures in June/July tend to be around 10-14 daily max and overnight minimums range from around 8 (overcast/northerly wind) down to 0.

House insulation is very good by local standards but I suspect only average for a home in UK/Europe - a long way short of passive anyway. We have a lot of north facing glass so it can heat up very quickly on a sunny day but that heat is gone by 3am if there isn't also heat in the slab.

This winter is our second in the house and my first where I've had all the sensor information and have used the underfloor as the exclusive heating source (we also have a logburner). Observations and questions that are on my mind currently are these:

Observations
- Comfortable for us seems to mean an internal slab temperature at between 23.5 and 24.5 degrees.
- Running the ASHP during the day to charge the slab with heat while it's warm outside for optimal COP seems to work best. I am still learning but depending on outside temp it seems to need between 2 and 5 hours of running per day to raise the slab temperature enough to get through to the next day - i.e. daily cycles.
- A cold night (near zero outside) will see the slab drop by a degree in 12 hours, when it's around 8 degrees it will lose heat at half that rate.

My questions
- I am wondering if I should run multiple shorter cycles rather than just the one long one per day in case the return temperature is getting too high and reducing COP.
- What would be the simplest/best logic calculation to use to program when and for how long to run the heating each day. I suspect some combination of current slab temp, current outdoor temp (for COP consideration) and forecast overnight low.
- Our hot water use is 90% in the morning and evening so this is when the heatpump runs to heat hot water - would it be more (or less) efficient to run the underfloor heating at the same time as it is doing the hot water cylinder?]]> Radiator retroconversion http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13621 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13621 Sun, 23 Aug 2015 23:17:56 +0100 gyrogear
I want to convert this to an hydronic unit, by fitting a hot-water manifold behind.

Would there be any problem having direct contact between my copper tubes, and the steel - the paint (white) is in very good condition.

gg]]> Using a radiator with a wood stove http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13619 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13619 Sun, 23 Aug 2015 01:07:12 +0100 gyrogear
Thanks

gg]]> A2A heat pump post heater? http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13612 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13612 Wed, 19 Aug 2015 11:00:25 +0100 djh
So the big question is does such a beast exist? i.e. a heat pump configured with the condenser inside a duct and a suitable control system.]]>