Tue, 19 Dec 2023 08:21:02 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15259 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15259 Sun, 27 Aug 2017 15:25:38 +0100 savagehk
Thanks :)]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15082 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15082 Thu, 04 May 2017 05:19:18 +0100 cjard
On models with a summer bypass fitted, the mode screen may have up to 4 choices:

Off
Normal
Evening Purge
Night time Purge

The unit has a clock, and it knows the day and time. I rang vent Axia tech because my unit was in Evening Purge mode, and had started to run a purge at 14:15..

Turns out, the evening and night time purge modes would perhaps be better named as "time limit purge" and "continuous purge" as they can happen at any time. The causes and effects are:

Off - the summer bypass will never open

Normal - the summer bypass will open if the extracted stale air is warmer than the set Indoor Temperature and the intake fresh air is above the set Outdoor Temperature, the fan speed remains unchanged

Evening Purge - the summer bypass will open if the extracted stale air is warmer than the set Indoor Temperature and the intake fresh air is above the set Outdoor Temperature, the fan speed switches to boost for a maximum of 5 hours and a minute timer counts down on the display. The boost deactivates if the timer expires or if the summer bypass closes (because the temperature conditions no longer apply).

Night time purge - the summer bypass will open if the extracted stale air is warmer than the set Indoor Temperature and the intake fresh air is above the set Outdoor Temperature, the fan speed switches to boost. The boost deactivates if the summer bypass closes (because the temperature conditions no longer apply).

You can check the temperature conditions the unit is currently measuring by holding UP and BOOST for 5 seconds to enter the diagnostic menu. Screens 1 and 2 have the temperature readings from the extract and intake sensors respectively


They weren't clear on what the reset condition is to allow the unit to enter another evening purge, but there must be one otherwise the unit would enter another cycle immediately after the current one ends, which would make it effectively night time purge. Perhaps the clock is used in this regard, in that an evening purge can only occur once per day, but the "evening" and "night time" labels have no condition related to the current time, as their names may imply]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15115 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15115 Tue, 06 Jun 2017 18:18:21 +0100 lineweight
It seems obvious that an open trickle vent is going to compromise the U-value, but is there a way of quantifying it, or is anyone aware of any standardised way of estimating it?

Every time I see a nice new well insulated window with a trickle vent in it, I wonder just how much of an improvement it actually is on the slightly leaky single glazed window it replaced. Does the presence of the trickle vent compromise it to such an extent that it's hardly worth the cost of replacing the old window, unless you have a more thoughtful ventilation strategy?

I know that in theory trickle vents can be adjusted, but I'm sure the reality is that most of them are either always open or always closed.

Occasionally I come up against the argument that it's dangerous to change windows in older houses to double glazing because it will create condensation problems. My answer of course is that it won't if proper consideration is given to ventilation. And in cases where the budget is small, trickle vents might be the only realistic means of providing that.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15047 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15047 Sun, 16 Apr 2017 09:23:54 +0100 ferdinand2000
I need 1 - a quiet trickle setting, and 2 - a boost. The boost can be manually switched or on a timer.

Usually I have used Vent Axia Lo-Carbon Tempra through the wall fans, which have been fine, but in this case I will be doing EWI so I would like to take it out via the ceiling to avoid penetrations, perhaps to a ventilation tile.

I have read the other huge thread currently running, but could not find anything which might be suitable here.

Thanks

Ferdinand]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13708 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13708 Wed, 07 Oct 2015 21:36:12 +0100 XT600 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14873 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14873 Sun, 29 Jan 2017 19:01:59 +0000 John Walsh
I'm installing a Sentinel Kinetic shortly and will then look at talking to it using python via the unit's RJ11 socket. As per the vent-axia supplied 'BMS Kinetic Current.docx' the unit simply acts as a serial device on a network and will act on/ reply to commands such as 'Sentinel Stop'.

The above should be fairly straightforward. What I'm also hoping - and this is the fingers crossed part / has anyone done this? - is that I can also communicate using the Control Unit screen examples shown in the Installation manual. For example, will sending 'Normal Extract 30%' set the Normal airflow speed? In a sense, I'm hoping to be able to 'emulate' the unit's Wired Remote Control (which is designed to connect to the BMS RJ11 socket).

One reason for doing this is that the house harvests warm air in the shoulder months, all controlled by a Raspberry Pi which monitors temps etc. When the Pi turns a fan on I'd like it to also reduce the mvhr unit's Supply fan speed and increase the Extract speed - thereby compensating for the air being pumped into the house from the solar gain spaces. According to the manual, this is similar to an 'antifrost' mode the unit adopts if the supply air temp falls below freezing. As such, the unit will happily run with unbalanced fans.

I suspect the tricky bit could be getting the unit to accept commissioning mode commands. Any thoughts or pointers on this are very welcome.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14885 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14885 Thu, 02 Feb 2017 10:05:57 +0000 tony
They are making holes in the walls of well insulated houses !!! For ventilation

And talking about "unintended air tightness" trying to use air leakage instead of proper ventilation.

And even worse "No insulation without ventilation" -- back to front thinking!

Damp mould and condensation is becoming an increasing problem in new houses and flats.

Build Tight Ventilate Right. Simples]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14735 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14735 Tue, 29 Nov 2016 14:59:10 +0000 MarkyP
I am planning to contact Fresh-R with a copy of my drawings and ask if they can provide a written installation proposal for their product and data on how it would meet UK regs. I'm prepared to explore this option, and discuss with my BCO who so far has been pragmatic and reasonable. I find the idea of a ductless system appealing but will also be looking hard at the tried and tested ducted approach as well. Up front cost will be a significant factor in choice.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13830 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13830 Sun, 22 Nov 2015 12:33:38 +0000 Cerisy
Has anyone got one to sell or hire out?

Currently we seem to be just about okay with the temperature in the house, but it is unusually mild so that's a little worrying! We always allowed for a wood burning stove as a back up heat source, but that won't go in until January - things move exceedingly slow in France! - so I need to cover all the angles to keep the OH happy.

Thanks, regards, Jonathan]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12684 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12684 Fri, 17 Oct 2014 11:33:30 +0100 Greenfish
Anyway having read the previous thread covering DIY balancing http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=6681, I have bought a small handheld anemometer and made myself a cardboard cone. Having run around taking measurents at each vent I get consistent air speeds (m/s) over time, and the expected ratio between normal and boost, but when I calculate the flows (l/s) I get values that are half or less the flows that the calibrated meter recorded. Is there more to the calculation than I realise? Is the hobby anemometer just not upto the job? What should I do with my velocities to get a volume flow? Do I need a length of straight ducting on the end of the cone to smooth the flow?

Advice anyone?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14810 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14810 Thu, 05 Jan 2017 20:23:52 +0000 Davegilsenan The problem I have that in order to get the flow from the unit, it needs to run 100% and the noise is unbearable. The measured flows and pressure bear no relation to the fan curve. Flow measured with all duct disconnected is about 60l/s and the fan curve indicates this should be over 100. The supplier will not accept there is an issue. They keep coming back to tbe fact the install is mot as the design. Compared to many systems I have seen mine is well installed. I'm not sure what to do. Am I missing something?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12026 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=12026 Sun, 27 Apr 2014 23:42:39 +0100 markocosic
http://www.ebay.co.uk/itm/VENTILATION-HEAT-RECOVERY-SYSYEM-UNIT-3500sft-MITSUBISHI-LOSSNAY-MVHR-EXTRACTION/191140682464

http://www.kievclimate.com/content/installationmanual/IM_LGH-50RSDC-E_EN.pdf

I'm considering using it as a glorified extractor fan. Is this madness? Are there better options for similar outlay?


This is a shared house. 4 people/4 double bedrooms and 2 bathrooms in 80m^2. The unit would be set to extract from the two bathrooms and supply fresh to the landing. Operate with timer switch operation on trickle speed then use a flow switch on the hot water outlet of the combi for boosting it:

http://uk.farnell.com/jsp/displayProduct.jsp?sku=1006772

This prevents lodgers from defeating it or having to faff about with (notoriously unerliable) humidistats. It also avoids noise during midnight toilet stops. (trickle is more than enough) With the the flowrate available it ought not to need any run on for showering.


Positives:

+Bathroom humidity control and heat recovery. Sucking air from the rest of the house ought through the bathroom doors ought to feel less draughty than an open window on a single room HRV unit.

+Overheating control. It has an auto summer bypass and some useful settings to control overheating. Supplies cool air to the landing and anybody else's room that's been left open during the day.

+Quiet and low power compared with the usual crappy pieces of plastic with AC motors.

+Control of pollen and airborne dust for hayfever suffering occupant.

+£550 is a decent price for DC commutated equipment with auto summer bypass.


Negatives:

-£550 is an expensive extractor fan

-It isn't exactly small (part of the reason they are cheap I think, as you can't stick it through a standard loft hatch)

-It has no intake air preheat to avoid icing.

-It has no condensate drain.


Will we fill it with condensate if operating it in the manner envisaged? Can a hole saw and some plumbing fittings create a perfectly functional condensate drain for emergency purposes?

Realistically will the unit ever ice up, or are intake air preheaters on only moderately efficient heat exchangers just a gimmick in the UK climate?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14624 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14624 Mon, 17 Oct 2016 17:57:21 +0100 Gotanewlife
The unit is still in warranty but then I am obviously not going to trash the airing cupboard where the MVHR unit is and then pay for delivery to NI in order to comply with the warranty T&Cs. So whilst they agree it is propbaly the PCB, it is at my risk and i have to pay for the PCB. C'est la vie.

However, it has always irritated me no end that the humidity control is a tiny 'pot' that requires gut instinct to set having no gauge/setting markings etc and that I have to climb a ladder, take off a load of sound insulation unscrew their not at accessible access plate (set between the 4 vertical 125mm pipes, which are obviously all lagged up) in order to fumble around with an utter guess as to what RH I am setting. I generally do this twice a year as with 3 bathrooms feeding the thing the RH setting seems to need to be reasonably close to the avg ambient to kick in (in the normal situation of only one bathroom being humid at a time), so close in fact that the summer winter RH are too far apart to work all year around. If I don't change the thing it will either not boost or stay on boost.

Sooooo. See below a dead cheap (£20!!) digital humidity sensor with inbuilt 5A relay and hysteresis function - it says temp corrected humidity, which I assume means %RH as opposed to absolute Humidity. If I am correct, I can parallel wire this in with my manual boost switch, set %RH accurately and, since it will be mounted on an accessible shelf in airing cupboard, change it really easily as per the weather. The only downsides seem to be that it is cheap Chinese electronics, I haven't yet found a solution for delivery to Italy yet and the instructions are so badly translated it takes a while to understand how it works. Here it is:
https://www.amazon.co.uk/gp/product/B008JLQXNA/ref=ox_sc_act_title_4?ie=UTF8&psc=1&smid=AG4A6CPO0BVL1

I would be really grateful for advice on my idea/alternatives. Especially as it is sooo cheap and MVHR manfs seem to charge a ridiculous (in comparison) amount for the Humidity function or stand alone humidity switches (like this one from Brookvent - note no details/spec on product at all, just pay them £70!!)
https://brookvent.co.uk/product/single-gang-humidistat-timer/

Am I missing something?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14610 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14610 Tue, 11 Oct 2016 15:12:28 +0100 Victorianeco
Thanks]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14154 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14154 Wed, 30 Mar 2016 09:35:45 +0100 nick1c The layout is reverse level with vaulted ceilings upstairs and no real space between the ceilings & floors. There are two rooms upstairs (living & kitchen) with three beds, hall and a bathroom downstairs. Granite steps lead from the living room to the garden. The entire building is rendered internally in cement.
As there was evidence of condensation inside I was interested in considering MVHR, but couldn't work out how we could fit it due to the layout of the building and lack of space to run ducting.
We have now got planning to build an ensuite and balcony on the back which has got me thinking again. Due to the position of the extension if an MVHR unit is housed in it ducts could easily run to the new bathroom, kitchen, living room and two bedrooms (less than 2m runs). We could also run an external duct, hidden by the balcony to the other bath and bedroom. Ideally this would be a single (extract) run, unfortunately the bedroom involved is the one showing most signs of condensation.
The floor area will be 105m2 and volume approx 270m3.
I realise that it is not an ideal situation for MVHR but would welcome opinions as to whether fitting it would be a reasonably efficient way of managing air quality in the house.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11540 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=11540 Tue, 17 Dec 2013 11:17:55 +0000 Gotanewlife
Elsewhere the 'paper' exchanger is described as: "Cross-flow polymerized cellulose enthalpy heat exchanger with heat recovery efficiency from 64% up to 72%"

But also described as: "Thermal energy recuperating efficiency: upto 68%. Moisture recuperating efficiency: Up to 65%."

The unit is a Vents VEU 100 P Mini; however, the Vents VUT 100 P Mini has a aluminium heat exchanger and a condensate drain but is not sold in the UK as far as I can see. Whilst I can see the logic it is hard to believe this system will remove as much moisture from the apartment as a unit with a condensate drain. There is also a bit where it says the VUT transfers 'sensible (sic) heat energy' from the extract air to fresh air in, whereas the VUE transfers both 'sensible energy' and 'latent moisture energy' to the fresh air in.

Anyway I have bought the damn thing now and I am irritated - especially as the various translations from Ukrainian don't all say the same thing or even add up and because the UK sellers don't highlight the issue (are they even aware of it I wonder). With uninsulated solid walls I wanted something to reduce help humidity/risk of mould in the winter. I don't suppose anyone here can tell me that my issue with this unit it is not such a big deal.............please :sad:]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13829 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13829 Sun, 22 Nov 2015 12:22:49 +0000 Simon Still
I want to get the system running even if imperfectly today and I've suddenly realised my knowledge is a bit lacking.

The MVHR unit is a sentinel kinetic plus. The performance graph is on page 9 of

http://www.vent-axia.com/files/pdf-downloads/439817Q_4.pdf

The system design shows that I need a "normal" extract rate of 228m3/hr. Am I right in thinking that I should be assuming a static pressure of about 150Pa running the unit at the default setting of 30%?

I need the static pressure to set the flow rate on the outlets. The airflow 125mm vents have a little graph on them and can supposedly be set up just based on this and a number of turns from shut. However, the x axis in m3/hr doesn't seem to go low enough - most of my rooms need to be set to about 23m3/hr but the x axis starts at 50

https://www.heliosventilatoren.de/mbv/ktva_poly_002_1210.pdf]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13610 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13610 Tue, 18 Aug 2015 16:29:15 +0100 JC48 Technical data
Article WS 320 KBET
Air flow volume 80 - 320 m³/h
Energy efficiency class A
Type of voltage Alternating current
Rated voltage 230 V
Frequency 50 Hz
Power consumption in accordance with DIN EN 13141-7 (A7) 36 W
Imax 11 A
Degree of protection IP 40
DIBT approval Applied for
PH certification yes
Housing material Sheet steel, powder coated
Heat exchanger material Synthetic material
Inner coating material Plastic EPP
Weight 73 kg
Filter class G4/F7
Connection diameter 160 mm
Connection diameter of condensation drain 1 1/2" (screen valve)
Width x height x depth 841 x 857 x 598 mm
Airstream temperature at IMax -15 up to 40 °C
Max. heat recovery rate in accordance with DIN EN 13141-7 (A/7) 93 %
Heat exchanger construction type Enthalpy cross-counterflow
Humidity conditions with enthalpy heat exchanger in accordance with DIN EN 13141-7 (A7) 70 %
Bypass, integrated yes
integrated frost protection integrated
Enthalpy heat exchanger yes
Antifreeze circuit yes
Summer circuit Exhaust air / supply air
Filter monitoring with time control
Humidity control integrated
CO2 -control (optional) SKD
Air quality control (optional) EAQ 10/3
KNX connection (optional) K-SM
MODBUS interface integrated
Control unit included in scope of delivery. RLS 1 WR, App
Control unit (optional) RLS T1 WS
EnOcean wireless integration (optional) E-SM
Mobile control yes
Housing emission sound pressure level 36 dB(A) / Spacing 1m, sound absorption 10 m²
Range K
EAN 4012799952275
Article number 0095.0227]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13405 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13405 Sat, 30 May 2015 20:46:56 +0100 gravelld
The house is five bedroom, 285 m². Three occupants but I'd like to be a good citizen and size it for the house.

Extracts in three bathrooms, one kitchen, two toilets.

Inlets in all five bedrooms, the lounge, the office and a dining room.

Step 1 is the supply rate. This is the bit that's scary. Part F suggests 29 l/s is fine for a five bed house, then goes on to say "In addition, the ventilation rate should not be less than 0.3 l/s per m²[...]". This gives the rather different figure of 85.5 l/s!

Step 2, the extract rate, I get the minimum high rate as 49 l/s.

Step 3 means both the "maximum whole dwelling extract ventilation rate" and "minimum rate" are both 85.5 l/s.

The discrepancy between the 0.3 l/s/m² and all other figures (standard 5 bed estimate, extract high rate) is what worries me.

Is it even required to do this to Part F, given it's a retrofit?

My initial look for units that can deliver 85.5 l/s haven't gleaned a single product... Although finding what they will actually deliver is quite hard on the product pages.

p.s. How do I convert 85.5 l/s to m³/hour? Using Google gives 306 m³/hour but units at BPC suggest they do more but are not unsuitable for our internal floor area.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13858 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=13858 Tue, 01 Dec 2015 06:14:03 +0000 chuckey Frank]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8522 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8522 Tue, 31 Jan 2012 16:03:00 +0000 brogie2805 Ventilation rate (m3/h) = Air change rate (/h) x Room Volume (m3). I have calculated that the total inlet ventilation to be 618 m3/h, however the MVHR report shows it to be 457.2 m3/h. Having researched the MVHR unit technical document it shows that the unit on full power to run at 460 m3/h. I'm no ventilation expert but this seems to be a big discrepency. I have been waiting for over a week now to see the design calculations the installers used in determining the unit that has been installed, however I am met with cagey answers. I will try and post some pictures of the mould situation to get your knowledgeable opinions as they're always greatly appreciated.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5230 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=5230 Fri, 22 Jan 2010 11:03:09 +0000 dan_aka_jack
Any thoughts?

The room is usually only occupied by me, my wife and the dog but occasionally we have friends around :)]]>