tag:blogger.com,1999:blog-14798090.post6711441089801846954..comments2024-03-27T06:42:31.956+00:00Comments on Mark Brinkley (aka House 2.0): Whither MVHR?Mark Brinkleyhttp://www.blogger.com/profile/03473684038478246288noreply@blogger.comBlogger42125tag:blogger.com,1999:blog-14798090.post-77992168945311200182011-10-25T18:45:29.658+01:002011-10-25T18:45:29.658+01:00We are currently looking at the ecorefurb of a ver...We are currently looking at the ecorefurb of a very large 1970's dwelling. The intention is to wrap in insulation and make very air tight. We are looking at using MVHR especially as we have 9 WCs/Ensuites. We do have some reservations though. There is no way the owners will want to keep the windows shut during the summer. We are therefore keen to provide a mix mode solution where during the Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-14798090.post-75697057205021089122010-09-01T12:08:44.954+01:002010-09-01T12:08:44.954+01:00I have to echo Barneys defence of the CSH - a holi...I have to echo Barneys defence of the CSH - a holistic look at how the house can influence the choices and lifestyle of the occupier to reduce their carbon footprint and is not just narrowly focussed on the insulation levels, air-tightness and orientation. On another point, my understanding was that a gas fired boiler was permissible under CSH Level 6 with emissions offset by a renewable energy?Cedric557https://www.blogger.com/profile/04801085968872858884noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-88967419355439352902010-04-13T02:01:14.101+01:002010-04-13T02:01:14.101+01:001. There is no requirement for MHRV in a Passive H...1. There is no requirement for MHRV in a Passive House - there is however a requirement for evenly distributed fresh air and high levels of comfort. So far I haven't figured how to do this manually, but if anyone can come up with a way, they can have a PH without MHRV.<br /><br />2. MHRV has been used in a number of extensively researched social housing apartment blocks in PH Standard in Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-14798090.post-73200979026845184912010-01-31T12:52:10.838+00:002010-01-31T12:52:10.838+00:00In terms of detecting if the MHRV is running effec...In terms of detecting if the MHRV is running effectivly or needed at all we should reflect on the future changes which might occur in the home<br /><br />My Morris 1000 of 1964 had 1 sensor - oil pressure<br /><br />My Galaxy of 2007 has in excess of 250 -<br /><br />both worked - both drove - and the only impovement in that time is from 25 MPG to about 38 MPG (of course this is not apples and Francis Chttps://www.blogger.com/profile/08951715236914668331noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-6771937186523713082009-11-25T01:16:51.547+00:002009-11-25T01:16:51.547+00:00I agree with Nick, there's no need to make the...I agree with Nick, there's no need to make the whole HRV system overly complex. All it has to do is supply some fresh air (the amount is debatable depending which authority one speaks to, whether it is the ASHRAE, CSA or whoever) and expel a similar amount of stale air with some degree of heat and/or energy transfer to the incoming air. If it's not exactly perfectly balanced, it's notUnknownhttps://www.blogger.com/profile/04159273748602638912noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-36010126164769794942009-11-24T11:35:20.259+00:002009-11-24T11:35:20.259+00:00FFS KISSFFS KISSNick Granthttps://www.blogger.com/profile/11949493936074643201noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-90688718775574566942009-11-24T11:34:26.556+00:002009-11-24T11:34:26.556+00:00This comment has been removed by the author.Nick Granthttps://www.blogger.com/profile/11949493936074643201noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-46126514032249246662009-11-24T07:03:30.618+00:002009-11-24T07:03:30.618+00:00Now from this conservatory example, you might fors...Now from this conservatory example, you might forsee an intelligent MVHR with self-regulating registers which respond to the conditions. This is what ITHO's Demand Control Ventilation system essentially is driving at. This ought (in theory) to be a vastly improved solution, but it would be technically even more challenging than regular dumb MVHR, and there is still little in the way of Mark Brinkleyhttps://www.blogger.com/profile/03473684038478246288noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-30712835945374519662009-11-24T06:31:23.264+00:002009-11-24T06:31:23.264+00:00Glad you didn't run away Mark
I can imagine t...Glad you didn't run away Mark<br /><br />I can imagine the thought process, recover heat from warm air in the conservatory to warm the house - err on hot days.<br /><br />Not stupid, just not done the maths or thought it through. If he had discharged the boiler flue indoors to recover the heat from that would this be evidence that boilers are an inappropriate technology for our DIY culture?<Nick Granthttps://www.blogger.com/profile/11949493936074643201noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-71685089484056275222009-11-23T17:58:41.636+00:002009-11-23T17:58:41.636+00:00I'm talking about half a dozen homes I have vi...I'm talking about half a dozen homes I have visited over the years, all selfbuilds, all well insulated, but none of them Passivhaus standard.<br /><br />Interestingly, one had a conservatory which was included in the MVHR network as an inlet. The owner tried to isolate the conservatory in winter and to manually shut down the register, but this simply threw the whole system out of balance. It Mark Brinkleyhttps://www.blogger.com/profile/03473684038478246288noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-79659457446450773012009-11-23T17:33:40.258+00:002009-11-23T17:33:40.258+00:00Mark, were these MVHR units used in ‘conventional’...Mark, were these MVHR units used in ‘conventional’ houses or in passive houses?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-14798090.post-20740172399655959672009-11-23T16:57:10.072+00:002009-11-23T16:57:10.072+00:00Nick,
You are right. It's turning into a foru...Nick,<br /><br />You are right. It's turning into a forum in its own right. <br /><br />To all, all I was ever trying to say is/was that I am not convinced that MVHR is a fit and forget solution. I have anecdotal evidence of people who have turned it off/taken it out/adjusted it and messed up the balance/closed off certain registers/getting mouldy bathrooms. And these were all people who Mark Brinkleyhttps://www.blogger.com/profile/03473684038478246288noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-49524368489675802352009-11-23T15:52:37.552+00:002009-11-23T15:52:37.552+00:00Poor Mark, the geeks have taken over your forum!!
...Poor Mark, the geeks have taken over your forum!!<br /><br />Ralph and Paul, the virus thing is interesting but as I mentioned PH is really clear on maintaining optimum humidity and stresses that people are more likely to complain about dry air than high CO2.<br /><br />Conventional UK M&E for non domestic buildings is far more likely to over ventilate and I have watched sandwiches curl and Nick Granthttps://www.blogger.com/profile/11949493936074643201noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-78214551668352092582009-11-23T15:26:11.107+00:002009-11-23T15:26:11.107+00:00Thanks for the links about virus lifetime and RH -...Thanks for the links about virus lifetime and RH - I'm happy to stand corrected!<br /><br />I think ventilation is less of an issue in houses with forced air heating than in those with other methods as the heating system naturally moves air (and hence humidity) around. Part of the problem in the UK is that people tend to be very zonal in their heating and tend to have bedrooms that are quite Unknownhttps://www.blogger.com/profile/04159273748602638912noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-42394279807497093272009-11-23T14:17:16.299+00:002009-11-23T14:17:16.299+00:00PaulM,
there is experimental evidence that flu vi...PaulM,<br /><br />there is experimental evidence that flu viruses survive on indoor surfaces longest at low RH (20%-40%) [2], and animal experiments suggesting that we may produce more viruses for longer at low relative humidity [1]. These are among the suspected reasons for why flu is much more common in winter, along with other "seasonal factors such as melatonin and vitamin D levels; Markushttps://www.blogger.com/profile/03781441235152966673noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-27389568946954513962009-11-23T13:48:25.195+00:002009-11-23T13:48:25.195+00:00Paul,
Here's a few reports demonstrating the ...Paul,<br /><br />Here's a few reports demonstrating the link between flu virus transmission & humidity:<br /><a href="http://www.webmd.com/cold-and-flu/news/20090213/influenza-linked-to-absolute-humidity" rel="nofollow">one</a><br /><a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.0030151" rel="nofollow">two</a><br /><a href="http://Ralph Doncasterhttps://www.blogger.com/profile/00037504544742962130noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-30526394385703271222009-11-23T12:13:24.547+00:002009-11-23T12:13:24.547+00:00Ralph,
I don't think there is any correlation...Ralph,<br /><br />I don't think there is any correlation between dry air and virus transmission.<br /><br />Your RH is so low because you have a very large volume house for the number of humidity generating occupants - so you may be correct that a HRV is not required. Typical UK homes are probably 1/4 of the volume of yours and so humidity levels are likely to be higher from this fact alone. Unknownhttps://www.blogger.com/profile/04159273748602638912noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-9996470307016785132009-11-23T10:42:50.424+00:002009-11-23T10:42:50.424+00:00I just got a phone call to say I was in trouble!! ...I just got a phone call to say I was in trouble!! :-)<br /><br />Wolfgang, I'm not against fresh air heating and do believe it works (in a Passivhaus). As you say it is not a requirement of PH and what I have to say on the matter will confuse this discussion so will be somewhere else.<br /><br />Ralph I can't comment on your low heating requirement without MVHR but would like to point outNick Granthttps://www.blogger.com/profile/11949493936074643201noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-21613390143327056942009-11-22T22:37:22.058+00:002009-11-22T22:37:22.058+00:00I live in a climate with 4520 18C degree-days and ...I live in a climate with 4520 18C degree-days and my heating energy use is <20kWh/m^2. Walls are 2x6 + 1.5" of foam, windows are dbl-glazed lowE/argon.<br /><br />Air tightness is 1.1ACH@50, and my MHRV is OFF, as it was most of last winter and likely will be most of this winter. RH & temp in the upstairs bedrooms is currently 47% & 18C.<br /><br />I heat with geothermal, so if Ralph Doncasterhttps://www.blogger.com/profile/00037504544742962130noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-26514292969183797182009-11-22T22:05:41.524+00:002009-11-22T22:05:41.524+00:00Paul,
You "don't hear of any problems wi...Paul,<br /><br />You "don't hear of any problems with using them" because many (most?) people don't know how to properly use them. I've seen many installs where the unit is run at low speed 24/7 and kicks into high speed with a humidistat. Combined with 2ACH@50 and cold winters (-10C days & -20C nights) gives an unhealthy indoor RH of 25% or less which promotes virus Ralph Doncasterhttps://www.blogger.com/profile/00037504544742962130noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-61436422173494436762009-11-22T20:52:26.560+00:002009-11-22T20:52:26.560+00:00@Nick Bad boy! Great danger! (:-). Well, that is a...@Nick Bad boy! Great danger! (:-). Well, that is a misunderstanding: PH is not based on air heating; you are still allowed to use each heating system you want - but please do not complain about costs. You could see it this way: Passive house is the energy standard, with wich the heating system used does not matter any longer - you could even use fresh air heating. And you will love it in a Unknownhttps://www.blogger.com/profile/11390641781108189396noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-13755443786104521962009-11-22T17:20:19.282+00:002009-11-22T17:20:19.282+00:00Love the last sentence Bjorn
However at the risk ...Love the last sentence Bjorn<br /><br />However at the risk of being failed in the Passivhaus Designer exam in a couple of weeks, I have to say I remain sceptical of air heating for most buildings even though it is at the heart of the whole PH concept, but that's another topic!<br /><br />NickNick Granthttps://www.blogger.com/profile/11949493936074643201noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-54952432053156367362009-11-22T10:07:23.183+00:002009-11-22T10:07:23.183+00:00Maybe you get a similar annual heat demand, but a ...Maybe you get a similar annual heat demand, but a much more favorable heat load. In your climate you can in general easily achieve a heating load of less then 10W/m2. That makes heating with the ventilation system possible. This saves also installation costs. This simplicity makes the Passivhaus standard so attractive.<br /><br />Don't lower your demands on airtightness and ventilation - theyBjorn (www.createrra.sk)https://www.blogger.com/profile/01182647974714165241noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-90760437591504944242009-11-22T09:39:21.771+00:002009-11-22T09:39:21.771+00:00Absolutely
And as we know PH approach is also app...Absolutely<br /><br />And as we know PH approach is also applicable in warm climates. Some of the general rules of thumb such as U values (inc glazing) will vary between climates but for UK it seems we need triple glazing and well controlled ventilation to meet comfort criteria without resorting to excessive energy use.<br /><br />PH approach is actually very flexible but does set backstops on Nick Granthttps://www.blogger.com/profile/11949493936074643201noreply@blogger.comtag:blogger.com,1999:blog-14798090.post-40375008865486560412009-11-21T23:36:22.819+00:002009-11-21T23:36:22.819+00:00I wish people would stop talking such poppycock re...I wish people would stop talking such poppycock re. the allegedly soft gentle English climate and the harsh German climate. <br /><br />The need for heating in kWh per annum for a given house is much the same in Frankfurt or Vienna as in Manchester. Try it in PHPP. <br /><br />If you start manually entering climate data for Scottish towns and cities in PHPP, you'll note how cold they are Anonymousnoreply@blogger.com