Tue, 19 Dec 2023 06:12:09 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15635 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15635 Wed, 21 Mar 2018 22:23:59 +0000 bhommels With a backboiler upgrade looming, I am considering my options. The system has underfloor heating, a few radiators, and a 210l heat store for DHW. As discussed in another thread, the DHW store needs to be at 50 degrees minimum to be useful, whereas the radiators and UFH only need 30-45 degrees water.
A system boiler could do all this, heating the heat store through the coil heat exchanger, which is a bit slow and prone to rapid cycling. Due to the large difference in output temperatures depending on who calls for heat, it will be quite hard to operate a system boiler efficiently at all times, using simple controllers.

Since the vented heat store cylinder has direct connection bosses, I was thinking that the hot water output of a combi boiler could in principle heat the store directly, provided it is fed with with the store water. It would give super-rapid recovery rates, and since combi boilers allow different set temperatures for the CH and DHW circuits, it would make the controls a lot simpler (potentially). It would require an extra pump perhaps, and that is something I can live with.

Any opinions on this please? Has anybody tried this? Any other ideas? Otherwise feel free to shoot me down :-)
Bart

PS A DHW only heat store might set alarm bells ringing, however it is heated by solar PV and provides all our DHW needs for about 7 months a year, so I am inclined not to "rip it all out and just install a combi".]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15605 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15605 Tue, 06 Mar 2018 08:50:29 +0000 andykent
My instinct had been telling me to move to a single unit with a storage tank for renewables and a system of room stats, but I am now questioning that. It's a town house and the scope for bringing in renewables is pretty limited, it has been useful to be able to time the upstairs and downstairs separately, presumably the room stat system would work the same either way, and I'm considering downsizing the house anyway so am wary of taking on significant ancillary works unless I decide to stay.

The older boiler is developing an accelerating leak which is beyond economical repair so I need to make a quick decision!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15599 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15599 Sat, 03 Mar 2018 20:24:57 +0000 VictorianTom
If we use a thermal store, how does that compare with an unvented cylinder in terms of the flow rate/water pressure that it can supply at a given temperature? Is it the same in each?

Given a thermal store, is it possible to upgrade it at a future date by adding more inputs? Put differently, do we need to buy a thermal store with all of the anticipated possible inputs in mind right now, or could we buy a thermal store with, for example, just solar thermal & gas boiler input, and then add another input at a future date, e.g. PV-T?

Similarly, could a thermal store or unvented tank on the first floor supply a bathroom on the second? Is that simply a question of sufficient mains pressure?

How do we judge how large a thermal store/unvented tank to get if we are just doing hot water?

If we wanted to run our heating system off the tank, presumably that would most easily be done with a thermal store. How do we go about calculating the size of heat store that we would need to heat the house, assuming that we knew the overall heating requirements of the house?

Is it possible to have a boiler supply the tank AND directly supply a shower & set of taps? In this way, if we ran out of hot water in the tank, we could just use the shower that ran directly off the boiler. Perhaps this behaviour could be switchable?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15553 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15553 Sun, 04 Feb 2018 21:39:06 +0000 2ev http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15530 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15530 Sun, 28 Jan 2018 17:45:55 +0000 RichKen http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15474 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15474 Sun, 31 Dec 2017 09:19:04 +0000 timmywo
After much research and thinking, I have come to the conclusion that I would like UFH on the 1st floor and do away with rads in our new build design (log cabin).
For such a system I am not that keen on having no thermal mass (so not embedding pipes into insulation or using aluminum heat spreaders), so based on costs and practicality I have decided on the following DIY design...

#Floor finish (hardwood / tiles)
#20mm Screed 4/1 sand/cement with added fiberglass fibers
#20mm EPS with pipe half inbeded
#Vapour Barrier
#18mm OSB Subfloor

I think this will give me the best of all worlds, weight, thermal mass, pipe to screed contact, costs while not following best practices in any one area.

I can see this is not ideal in many ways, but it appears the design of such things is based on one's needs and the above meets mine.

Keen, as ever for feedback.

Many thanks and an early Happy 2018 :surprised:]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15463 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15463 Mon, 18 Dec 2017 23:43:37 +0000 mike7
Provided that the source emissivity is 0.9, the answer is 6 Watts per square metre for each degree C difference between the source and ambient - roughly.
How rough? It depends also on the mean of the source and the ambient temperatures. If that mean is 35C, eg say 50C source and 20C ambient, it gives a very accurate answer of 6 x 30 = 180W/m2

If the mean is not 35C the result will be lower or higher by 1% for every degree C lower or higher. Thus in WillinAberdeen's warm ceiling idea the source was 30C and ambient 20, so the mean is 25C, ie 10C lower than 35C, and therefore the answer will be 10% lower than the 60W estimate, ie 54W.

The whole thing assumes that the emissivity is 0.9, which is a fair guesstimate for many likely surfaces but if you insist on chrome plated radiators for example, then there would be a large adjustment to be made pro rata for a very different emissivity.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15441 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15441 Thu, 07 Dec 2017 21:07:23 +0000 cjard By doing both sides

Perspex sheets look to be around 20£ per sqm, so I'd be looking at around 1000 quid to do the windows. The roof glazing might add another grand

In terms of house heating costs, I don't have a great idea of what my heating costs to run because we haven't been charting it long. Broadly speaking it looks like 30kWh/day in heating season and 20kwh/day out of it.

I've nearly 100sqm of glazing, not worried about the walls/roof as they're around 200/300mm of kingspan; it's the glazing that is the loss path I think

So, handwaving generalised values; is there any worth (money saving) in applying a system of tertiary glazing? I didn't buy triple at the time for several reasons including weight and price (quotes 50% more). As well as the money actor, there's a comfort factor too, as the bedrooms at 16 degrees cause a lot of complaints from the boss even though I like it: is adding another layer of immobilised air likely to appreciably improve the insulative value of the glazing (as compared to argon filled triple)?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15442 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15442 Fri, 08 Dec 2017 16:53:34 +0000 RichKen
I live on the Isle of Wight and have just had gas piped on am looking to have a full gas central heating installation carried out. I find that the people I have approached to quote find every excuse to not provide any references. Is this normal? Before spending many thousands of pounds and having strangers in my house for a week I feel that it is only prudent to be able to talk to a couple of customers who have had a recent full CH installation. Am I expecting too much? Many thanks. Richard]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15424 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15424 Thu, 30 Nov 2017 13:41:14 +0000 tony
Any explanations or views? Source -- WinterWatch worker in my town.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15414 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15414 Sat, 25 Nov 2017 21:28:49 +0000 harhenmemorials@eirc I have 2 buffer tanks each 1000 litres, the system is about 4 years old, it is located in my garage about 10 metres from my hot press.
I am not sure the system is installed correctly and I would like some help if possible.
The boiler output pipe goes to the top of one tank but there is a feed off this pipe taking water direct to my hotpress,in other words the boiler is supplying my heating with any spare water going
to the buffers.
The problem I have is that my boiler can be producing water at 75 Deg for example but the supply reaching my heating can be as low as 40 Deg think the heating pump Is pulling water both from the boiler and the buffers, and if the tanks are down it's reducing my feed temp to the heating.
Can I fit some sort of valve that would isolate the buffers if the are below a certain temp but yet would allow them to fill when the heating is not taking any more hot water.
I am not a plumber, and any advice I can get here would be really appreciated as my plumber is not sure of a solution,by the way I am based In Ireland, co clare on the west coast.
Thanks for reading this]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15364 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15364 Wed, 01 Nov 2017 10:13:02 +0000 Andy M Is it possible to use the same ASHP to heat a pool in summer and also run UFH in winter?

Cheers]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15294 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15294 Fri, 15 Sep 2017 15:04:31 +0100 jwd
Can anyone suggest a simple way to test if my heat meter is giving accurate readings?

I've got a 40kw log gasification boiler with a thermal store. It has a heat meter installed because of a backup oil boiler. My meter readings are much lower than expected. The meter didn't work properly at first as the return probe was incorrectly installed but since then it's still giving lower readings than I had hoped - about 15% of what I expected from the heating requirement calculation for the deemed rate.
The house is tenented and the tenents tell me they have been using wood almost constantly and have hardly used the oil boiler at all.

The boiler burn chamber has a capacity of 185 litres and is located in an enclosed boiler room and the is in the adjacent room, inside the insulated envelope. the heat meter probes are fitted close to the thermal store on the flow and return. The water in the tank has inhibitor in it. The wood fuel is dry and mainly norway spruce.

Any advice would be very welcome.

Cheers

Jwd]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15339 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15339 Thu, 12 Oct 2017 07:59:19 +0100 Victorianeco 2. How much difference will be noted if one rad is fed with 10mm pipe compared to 15mm? Bearing in mind I'm running a low 35c flow temp....]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15304 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15304 Fri, 22 Sep 2017 19:03:57 +0100 Caterham07
An ESi Electronic Dual Cylinder Thermostat is attached to the Store but has been added after the original installation and not commissioned properly.

The Store Thermostat is wired as follows. Perm L&N. The Switch Live "Boiler Out" from the Wiring Centre is going into the HW-On Com terminal in the thermostat. A single wire goes from HWS N/O in the thermostat to a fuse input terminal through to activate theCirculation Pump. The Boiler Switch Live is inserted in the same input terminal and is made Live as the power passes through to the Main Circulation Pump. It works for maintaining the heat store temp for DHW.

However on the heating demand side, when the Wiring Centres activate, the blender pumps start as required but the Main Circulation Pump does not activate. No hot water is round the loop to the manifold from the Store. Moving the Wiring Centre Switch Live to the Main Circulation Pump Fuse input makes this work.

What is missing is the ability to activate the Main Pump from either the Store Thermostat and / or the Wiring Centre.

My thinking has been as follows ....

Bridge the Perm Live and HW-On COM terminals within the Store Thermostat. Take Boiler Switch Live direct from Store Thermostat HWS NO. Also take a Switch Live from same HWS NO terminal to Fuse input terminal leading to the Main Circulation Pump. Wiring Centre Switch Live to same Fuse Input for Main Circulation Pump.

Questions.
I think I will have a backfeed problem because SL for Wiring Centre and Store Thermostat are connected at the Pump Fuse input ?

How can I activate the Circulation Pump from either or both of the Switch Lives without backfeed ?

I want to avoid the boiler turned on every time the Wiring Centre calls. I want the boiler to be controlled solely by the Store Thermostat. My concern is SL from Wiring Centre backfeed to Store Thermostat and activates Boiler Switch Live at HWS NO Terminal which they would share.

I have run out of road on thinking this through and would welcome some advice. Are relays the answer ?

Thank you for taking the time to read my ramblings ...]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15322 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15322 Fri, 29 Sep 2017 12:42:06 +0100 cjard http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15324 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15324 Sat, 30 Sep 2017 21:28:35 +0100 woodgnome
Trying to open this link, but it doesn't work.
Can anyone else find it?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15316 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15316 Wed, 27 Sep 2017 10:35:41 +0100 Silky
The 1st couple of things I'm confused on is that I've read a couple of recommendations that it should be installed on the external walls and that most manufacturers presume the installation of an internal insulation behind the pipes.

I had presumed that I would install on internal walls mainly opposite the external walls with windows, without insulation, so that any heat 'lost' behind will simply add to the whole building, and therefore I will design as far as possible to have the heating elements also 'back to back' on the same internal wall where possible. But this is just me making it up.. am I missing something with the external wall recommendation? I suppose in a way this is the same as putting radiators under windows because that is where it is the coldest, does that also make sense in a well insulated house, or better to keep heating elements away from external walls?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15312 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15312 Tue, 26 Sep 2017 13:38:27 +0100 Caterham07
The Akvaterm Solar Plus store in a house I have bought is only connected to an Oil Boiler with three standby Immersion Coils as a basis for additions for heat sources next year. It is providing DHW and UFH.

The Supply side is currently drawing water from the top coupling, through the boiler and returning to bottom coupling. When I look at schematics online, they seem often to drawing from the bottom and returning to the top. What is most efficient with this type of store ?

On the Load side, the UFH is also drawing from the top coupling and returning to the bottom coupling. It has been suggested to me that it could be drawing from the mid level coupling, just below the baffle, and returning to the bottom coupling given the lower temperature required. Is keeping the cycle below the baffle a better option, or leave as it is ?

The tank thermostat is in a pocket above the baffle.

I am learning every day on subjects such as Stratification and appreciate the future use of the solar coils may change the optimal solution.

Many thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15286 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15286 Tue, 12 Sep 2017 19:21:19 +0100 Gotanewlife
Anyway the point of this post is that this is no longer theoretical for me. We have decided to install one and it will be the Infinity 11e at just under 600 euro (I live in Italy), unless anyone has a suggestion for an alternative (cheaper!) boiler. It has to be mounted outside as I don't have space inside but it will be in a bespoke 'pretty' house as I am under orders on this and it will never be used when it is near freezing so an 'internal' boiler might also work.

The purpose of this is to prevent me batch burning up to 10 time a year; more importantly it will provide me with certainty during the shoulder seasons (when I don't need to space heat) that my in-laws (who live in their own apartment within my house) will have DHW if I am away. I can't go away during the summer due to work or during winter as I must batch burn daily.

So:
1/Any recommendations on a cheaper appropriate boiler?
2/Should I be looking to bypass and drain down the boiler when it isn't needed, ie summer and winter?
3/Am I right in thinking that this Max 22kW boiler will use about 1.6kg/hr if flat out?
4/Any other thoughts to ready me for a potentially stuck in their ways gas engineer who will be giving me a quote - ie any thoughts to help me become an intelligent customer?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14472 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14472 Fri, 12 Aug 2016 12:57:29 +0100 lcforbes http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15280 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15280 Thu, 07 Sep 2017 11:38:51 +0100 Pile-o-Stone
I'm now reaching the stage in restoration where I'm looking to replace the +20 year old ground-floor stove with a more efficient new one. The original plan was to install a boiler stove, but I've had a few people tell me to just fit a non-boiler stove to save hassle and money. They also said that non-boiler stoves last much longer.

We don't have access to much free wood, so I'm not sure how much (if any) saving there is with wood over natural gas. The stove will be in the kitchen/diner and we generally sit in the living room upstairs, so I don;t think we'd be re-fueling the stove as much as we would if we were sat around it all night.

I'm therefore leaning towards just having a non-boiler stove fitted, which would just require a new chimney liner, rather than a boiler stove with pumps, mixer valves, overheat radiator and pipework. Am I being short-sighted though and would a boiler stove make savings on my fuel bill to make the installation worthwhile?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15260 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15260 Sun, 27 Aug 2017 16:43:02 +0100 Seret
Just about to fit a new Intergas boiler to my extension and I was wondering what people's thoughts were on the best way to make use of Opentherm?

Currently my nasty old boiler is just on on/off control, with two thermostats dividing the house into upstairs/downstairs and eTRVs preventing individual rooms from cooking. The CH is all one circuit, and that won't be changing.

I was leaning towards the Honeywell Evohome, but it's frankly bloody expensive and I don't think it makes any sense from a cost/benefit angle. Happy to cough up for the central controller, but £55 per TRV on top is pretty cheeky IMO. IIRC my current ones cost less than £20, although admittedly they don't have the features you'd get in an HR92.

Worth just biting the bullet and going for the gold-plated Honeywell system, or am I missing a good alternative?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15249 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15249 Tue, 22 Aug 2017 13:11:49 +0100 kates
We are part way through a 4 bed detached house refurbishment of a 150 m2 house which involves insulation, triple glazing, MVHR, a new gas boiler and 12 aluminium radiators, and a 4,120 kWh/yr PV system with solar iBoost. Our SAP predicts the house will need a total of 17660 kWh/yr input (11576 kWh/yr for space heating and 3540 for HW).

There will normally be 3 occupants but 6 fairly regularly, and we will have one bathroom (bath/shower) and one separate shower. One of us has a medical condition that requires plenty of mains pressure HW for decent showers.

Does a 18kW regular boiler with a 250l vented thermal store sound sensible for our needs? Any other advice also welcome.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15255 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15255 Thu, 24 Aug 2017 18:59:14 +0100 ringi http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15233 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15233 Wed, 16 Aug 2017 11:22:16 +0100 LittleJim
We are currently renovating a 2-bed, 2 lounge, one kitchen, one bathroom, very old stone cottage. At the moment the heating is by a solitary 5kw stove in one downstairs room. We intend to install an 8kw stove in the other downstairs room and attach a back boiler (3kw). Could anyone suggest what tank would be suitable? I'm not clued up about all the different sorts on the market - vented, thermal store etc...

We are thinking a smallish tank (there are only 2 of us) in the bedroom above the stove with the back boiler.

Eventually we hope to have solar PV that should go some way to helping with the hot water and also help run an electric Everhot cooker in the kitchen.

Any advice would be very much appreciated.

Thanks.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15223 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15223 Wed, 09 Aug 2017 23:59:27 +0100 carrotandturnip
Two sweeps can't make any impression, one with a normal brush, one with a plastic flail. Reaching in through the sweeping door, it's very difficult to remove with a paint scraper, but small pieces can be chipped off by hitting it with a chisel. This is after burning smokeless fuel (virtually no wood) for two winters, and after spraying the bits I can reach with a strong solution of caustic soda (100gm water, 45 gm caustic soda, very nasty, take great care).

I've read of a product that's claimed to make it friable (Creaway) but can't find anyone who uses it in this area (south Cumbria or north Lancashire).

We intend to have a liner fitted after the creosote is removed. Please can anyone suggest a course of action?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7611 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=7611 Fri, 22 Jul 2011 09:49:12 +0100 Benpointer
That got me thinking, why do I need filters? We are not hayfever sufferers, so not bothered about pollen (and in any case have the unit off and windows open during the summer). It's good to keep insects out but I could easily make some permanent mesh filters to achieve that? There'd be the added benefit of less air resistance in the system so less enregy running costs, i'd guess.

Anyone think why this might be a bad idea?

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15215 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15215 Fri, 04 Aug 2017 08:30:15 +0100 crt
Guidance seems to be that you can go with shorter length if stove manufacturer says it's ok.

This must be doable as plenty of stoves seem to go into single storey workshops, conservatories, and shepherd huts etc, but I am finding it difficult to get any info about stoves that will work properly with short flues.

(I've looked at Vesta, but their technical info is silent on the point, even though they are marketed as short flue compatible, and the person I spoke to there was vague about it).

Any ideas?

Thanks.

CRT]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15217 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15217 Fri, 04 Aug 2017 15:59:40 +0100 Victorianeco http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15207 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15207 Sun, 30 Jul 2017 16:25:07 +0100 ComeOnPilgrim http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15192 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15192 Fri, 21 Jul 2017 13:52:32 +0100 tony https://www.dropbox.com/s/8xt2gjpaghnf0q7/mystery%20rad.jpg?dl=0]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15173 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15173 Sun, 09 Jul 2017 15:38:41 +0100 TimSmall
https://blog.x.company/introducing-dandelion-2706eded169a]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15152 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15152 Sun, 25 Jun 2017 16:34:16 +0100 colin440 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15162 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15162 Fri, 30 Jun 2017 12:29:08 +0100 Peter_in_Hungary http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15141 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15141 Wed, 21 Jun 2017 09:29:58 +0100 revor
Thank you.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15117 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15117 Tue, 06 Jun 2017 23:45:56 +0100 DavidND
I fully realise it needs to well insulated, but I can't find anywhere that will do me a 4-5M length of insulated 15mm twin pipe :sad:

Just so you're aware, it will be controlled via its own zone valve and only occasionally used. We aim to bury at least 400mm down to top of the outer casing. It will come up inside the two buildings.

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14256 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14256 Wed, 11 May 2016 02:02:43 +0100 gyrogear
and wonder if anybody has ideas regarding this "selective solar varnish" that I'd like to get my paws on...
The idea is to stack heat up behind the slates, rather than have them radiating it all back out to the cold.

I looked up "Solkote", but it is not usable for my application (slate cladding)...
(http://www.solec.org/solkote/solkote-technical-specifications/)

Otherwise I am "stuck" with straight roof varnish, which seems to be a waterproofing solution, which is not what I need neither...

Thanks for any help or pointers

gg]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10862 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=10862 Mon, 08 Jul 2013 09:23:41 +0100 dgmartin
I have loads of temperature monitoring through the house and can see the 4 temps in the ducts to/from the house. So I can see when the bypass switches in, and can see the effect.

Let's say I think the effect could be better. I think loads of air is bypassing the bypass, but we'll overlook that and continue ... what I'd like ideally is more manual control of the bypass. In hot summer weather I'd like the bypass open all night to get maximum cooling, instead of closing again when inlet temp drops to 21C.

Yes I know I could change the bypass temp, but perhaps there is a way I could more easily control the bypass either via a controller, or a connection to the unit?

I'd be grateful for a tip from anyone with experience - thanks ... David]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14972 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14972 Fri, 10 Mar 2017 14:52:45 +0000 lineweight
It seems they are really intended for bathrooms and kitchens as an alternative to conventional extract fans. But it looks like some people have used them with the aim of dealing with an area extending beyond that.

My question, basically, is:

Is there any real-world data or even theory that lets me judge or understand how great an area/volume they are going to have an effect on?

At first glance it seems that because, unlike ducted systems, they can't have the intake and extract at different locations, they can only have quite a local effect. A certain proportion of the air they pull in must end up going out again before it's circulated very widely. I assume they are designed to push the air in a different direction from where they are pulling it from.

I realise it may be a bit more complex than just where a body of air physically moves to though. I have a half baked understanding that humidity will tend to even itself out within a space but I'm not clear to what extent (if at all?) the moisture can "move" from a humid body of air to an adjacent dry body, without the air itself circulating.

At a pragmatic level, the question is: will one of these in-wall units have any chance of having a meaningful impact on humidity or CO2 levels at a point, say, 10m away?

I'd be installing it in an open plan living space containing a kitchen area. It's highly insulated and pretty airtight, with the complication of being connected by an open stairwell to a not-so airtight lower storey. Almost all of the time it's unsurprisingly considerably warmer in the upstairs area, and my feeling is that humidity from cooking sits in this warm air upstairs and has little impact downstairs. At present I deal with it by opening windows. This is pretty effective but obviously involves dumping a load of heat away.

In a way, it's more general air quality I'd like to address with the MHRV. Humidity is actually easily dumped out the windows as described, and if I've been cooking, if anything it's already too warm so a bit of cool air from outside is not unwelcome. But I do sometimes feel the need to open the windows a bit at other times of day because it feels stuffy. In that scenario, during the winter I'll notice a temperature drop that's not so welcome.

Is a heat exchanger unit going to have a noticeable impact if it's 8-10m away from where people are sitting?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15064 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15064 Mon, 24 Apr 2017 12:21:52 +0100 Pidgeon
As I'm pretty much starting from scratch what are any suggestions? Looking at electric options as well as gas. Multi split A2A with ceiling cassettes is appealing, obviously then need a DHW solution.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15025 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15025 Sun, 02 Apr 2017 21:37:18 +0100 Pidgeon
Looking for some advice, I'm renovating a 2 bed flat (~75m2) which currently has no heating/hot water system. I took a punt and purchased a used energie solarblock with 8 panels. This was with a view to heat a cylinder/rads to around 40*C and supplement with instantaneous water heaters where needed for DHW.

I'm having issues finding someone to install the system, I'm in North Yorkshire, can anyone provide any pointers? Have contacted some aircon/heat pump engineers but no luck so far. Keen to get in someone, if I do, that's experienced working with refrigerants. Failing that has anyone installed a thermodynamic system themselves? The installation manual is fairly comprehensive, any hidden pitfalls?

Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15023 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15023 Sat, 01 Apr 2017 07:29:40 +0100 cjard
I don't doubt that having 30% of the roof be glass (heritage reasons, perhaps not ideal) is a significant source of somewhat unwanted heat so I'm thinki of cooling options for when proper summer is here (because if it's 24 inside in March..)

Call me daft, but I've always had this idea that I'd put an air source heat pump inside the house for two reasons: one that they produce cold air as a byproduct of their operation and two, that I'm still going to need hot water that I need to pay for, so pointless running the outside heat pump and cooling the world when what I really want is a cooler house

At the moment it feels like it would be more sensible to make the system independent of the MVHR rather than try to integrate it: the base of the house is generally cooler; it's just the top floor and knock on effect it has on the Middle floor that causes warm bedrooms.

Before I get too involved with questions like what size of machine, does anyone think this is a bad idea? I Plan to activate it only when out the house/not trying to sleep.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15035 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15035 Sat, 08 Apr 2017 18:04:45 +0100 goodevans
Sap calcs for my situation looks like a target value of around 205W per Kelvin for the nominal dwelling, my build shows 145W/K - but approx 30 of that is penalty psi values which won't be there, and perhaps another 10 or more to come off in better windows than the default 1.4 lambda values.

Leaving approx 105W/K to heat.

I am not going to go for high solar gain option - my plan is for steady comfortable living in winter (through moderate heating) and in summer (on hot summer days - house sealed up to keep the internal temp lower than outside). Location Cambridgeshire.

We tend to keep our house on the cool side in winter (18degC), but the house is occupied all day - on average waste heat could be around 500W with cooking, living, appliances etc so I think additional heating would be small (can anyone give me an annual and peak KWH for this situation)

Starting from the simplest - low capital option....
Electric only, in line hot water heaters at every sink/shower (no bath), Fan heaters where / when necessary

to the most complex high capital option...
Solar PV, Excess PV to HW store, Small regular gas boiler, DHW via heat exchanger on HW store, UFH From HW store.

Or anything in between.

To keep this thread focused on the heating/DHW the rules are 500w waste heat heating the house on average, 105W/K loss to outside - Assume the house has MVHR, EWI, medium density solid wall blockwork.

Is this house efficient enough to go for low capital outlay and on demand electric heating/DHW?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14989 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14989 Fri, 17 Mar 2017 21:13:29 +0000 johnnyh
Thanks in advance,

John.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14971 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14971 Fri, 10 Mar 2017 13:48:32 +0000 jamesheath
The (quite large) Passive House I'm having built for me is going to be heated by a combination of (mostly) air heaters on the MVHR, and towel rads in the bathrooms and cloakroom.

The M&E designer says I don't need TRVs on the towel rads - by tweaking the mixer valve on their heating circuit and adjusting the Towel rad valves, we'll be able to get it right.

TRVs are not hugely expensive (though I would need a few), and would seem to me would give me a set temperature.

Does anyone have any direct experience of living with such a set up?

Thanks,

James
Hove]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14955 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14955 Sun, 05 Mar 2017 06:19:59 +0000 countryman
We do not have any UFH nor intend to put it in because even though we will be insulating the inside of all the external walls with 100mm Kingspan I think that the house will still be relatively inefficient from a heatloss perspective.

The current system is vented and we are on a private water supply and so no mains pressure to consider. Or take advantage of!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13321 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13321 Tue, 28 Apr 2015 20:28:00 +0100 johnsanctuary Their engineers could'nt find any fault and measured the temperatures at the MVHR unit as
18c stale air out
12.8c Air in to rooms
8.6c Outside air temp
Which they calculated the efficiency of the system at about 45%.

The stated efficiency of this unit is 70% and when I challenged the manufacturer the reply was that even at 45% this was better than if you had trickle vents when the air would be coming in at 8.6c!
Ive had little help from them and before I go back again I just want to be sure that I have a case.
They did say that the inlet fan was running slightly quicker than the outlet and they would send a manual controller that I could fit - i have declined this offer

Any comments would be appreciated]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14957 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14957 Sun, 05 Mar 2017 17:00:29 +0000 alec
The annual kwh usage went down from 62000 to 49000. Degree data from the London city weather station indicates the 2nd year was actually colder.

The client comments that the house was warmer than ever before.

Compensation controls are something we have to get used to, it seems!]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14970 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14970 Thu, 09 Mar 2017 21:56:20 +0000 djh
* Well, I left the ventilation at trickle setting overnight, which has the side effect of causing the post heater not to switch on because its sensor detects that the flow rate is not sufficient.

It was up to 24°C in the living room late this afternoon, so I must get on with my pergola! The situation is not that desperate, because if the rest of the house warms up to that sort of temperature then the MVHR summer bypass will operate to stabilise things. As it was, the rest of the house was around 21°C - 22°C. Well, except for the conservatory (really a sun room), which got to be too hot for me to spend any time in, as designed.]]>