JohnMo

Yes. MVHR and actual cooling ability is pretty rubbish as flow rates are small. I was talking about management of humidity margin in cooling, so the RH is actually lowered by the MVHR. Having the unit upstream of heat exchanger cools the air and causes it condense, then it's reheated by the outgoing house air via the heat exchanger changing the RH. Net effect is lower RH when compared to outside air. One of the issues in winter with MVHR is it lowers the humidity levels too much with prolonged cold outside temperatures, you are just duplicating those effects to your advantage.

I was thinking about this last night also. A coil upstream of the MVHR unit (outside to MVHR leg) would cool the air and cause condensation which would reduce the moisture carried by the air. Condensation would be cleared away by MVHR drain or drain within heat exchanger. As outside air travels through heat exchanger it is then heated by house air temperature, diving RH to a happier place. Then run MVHR as normal and get lower internal humidity and more dew point safety margin.

Aren't you better to run the MVHR at the normal speed. Then the MVHR actively pulls the humidity out the house, moving dew point upwards.

Not if oxygen is really the issue as you get more airtight, it's dilution and getting of excess CO2 and removing moisture. Other thing you will notice as you get airtight is opening an outside door doesn't blow through the house, unless you have a window open as well. As it has nowhere to blow out off.

But remember MVHR only changes house air every 2 to 3 hours, so in cooling/heating terms pretty rubbish.

Please help me understand? A fan takes the internal (24°C) air out, through a heat exchanger. It partially cools the incoming air currently at 33°C If house is cooler than outside The heat exchanger is a counter current one, so the air entering the heat exchanger from the house and leaving the exchanger to enter house are at the same end. This gives an approach temp that is very close. So if air in house is say 22 the air being pushed into house will be sat 23/24. So will warm house up over many hours. Warmer inside than outside the air is warmed to very close to the inside air temp, this will cool the house but very slowly - many hours. In summer a bypass around heat exchanger operates to allow cooler outside air to by go around the heat exchanger.

I can work BUT Flow rates are pretty much multiple times higher than normal MVHR flow rates as set for BR or Passivhaus. Download datasheets read water flow temp requirements, air flow required and kW of cooling output

Is it insulated? If so it should straddle the insulation where we that is, other than a set distance. If not insulated then any distance to suit how things look

Start a new thread, include model and size. Mine has moved to hot tub heating duty and I replaced with a smaller heat pump. Do you have the full version of the controller manual? Both R290 and R32 are available online.

You can easily add them, I just read the flow and return temps of the heat pump and or performance monitoring.

That is just a set up issue, are you running a fixed flow rate? Hydraulically separated etc. what heat pump? That is generally ok short term, but if your heat pumps decides to latch on and over long period can lead to condensation on floor surfaces and lead to slips and falls.

I am a NIMBY blamer, we have had land compulsory purchase for road improvements, no issues with that as is for the greater good, less people being killed on a road next to us which is an accident black spot. Main electric line is being improved again near us to help move wind generated electric from A to B, we are within the area of notification so it's all pretty near to us. Again no complaints from me it's for the greater good, but plenty of others who can't see, won't be affected by the changes are complaining.

Me thinks you miss understand me. No the very opposite is true, from proper sources I do trust the figures - ONS is one of them. We are a wealthy society, look at the amount of pretty new cars are on the road these days compared to the 70s. But the money allocated to councils, roads NHS, schools isn't well spent. So as @Indy points out stuff is going in the wrong direction. Your rose tinted specs may not allow you see it. All very true. But certainly in Scotland we have almost the same road system as the 70s. Back to one of my original points, change is way too slow, not helped by continued changing of plans to keep many a NIMBY happy. Which causes delays and additional cost. Aberdeen has a nice peripheral road now, but it only 20+ years to get started on building it.

Is that code for I can't be arsed. Or I can't find anything that supports my assumptions?

Your the man with numbers - show us. Pot holes Waiting lists School success Wealth difference from the rich in society to the rest us. Generally thing that matters to normal people Those are the things I spoke about. Without those being maintained the country slowly goes down the toilet - if you find a public one anymore.

Good, point, but NIMBY's aren't a good solution either. They just cost a load of tax payers money and everything takes an age. Leading to a great deal stagnation - Just as the UK is at present, slowly turning into a mess.

But with an average of 27 pupils per class in UK, that's nearly 25% higher than other European countries, with closer to 20, so you can play with statics any way you want.

Really wasn't the point, it how many beds are available per capita, same for police, schools etc. not where the person comes from, giving the care. But it bonkers our UK trained school teachers, doctors and nurses aren't getting jobs.

Petty the services haven't kept up, (schools, hospitals, doctors, dentist police) with population growth

With decent bypasses around towns that don't cost millions extra, take decades to get through planning to keep a few happy. Aberdeen bypass was delayed for decades to keep a few idiots happy. Not forcing way too much traffic through town and city centres instead of around them. A96 bypasses delay for decades again because a few complain (mostly farmers trying to squeeze the last £ from the deal). We would have had onshore wind and solar in England developed over the last decade. For the greater good doesn't for the lowest common denominator. It also means knocking down slums and generally crap building people are made to live in and replacing with new.

They don't do that. In cooling mode the 4 way valve starts in cooling mode. Otherwise it would end up chasing it's tail. But in periods between cycles (circulation pump on) it may see this as heating or cooling dependent on what temperature is see on the flow or return. But as Vaillant is a default heating ASHP with an additional widget to get cooling, it may just count everything that is not active cooling as heating anyway. It's energy used one way or another so would be included in the CoP (EER) calculation if your doing that.

Just embrace them, make them a feature. Be proud to be doing your bit for your pocket first and the environment second. Nothing wrong with panels on show. In six month time you will going out to see they are still there, because you and no one else really sees them.

When I did a degree in 2001, one of the topics then was global warming, strange weather patterns and prolonged draught periods. Then the sea levels rises and floods the aquifers with sea water - then the next major wars start, over possession of water rights - Joy

Just ban it, just as Singapore did and put in place a law for the "greater good".

Don't you have dial a bus? Thought most places in rural Scotland had it, plus if your over 60 it's free. A mate used to drive one of the mini buses and people would take a ride from here to there and back again, spend 5 mins doing something while the driver waited then took them back home