MVHR & New Electrical Installation

[Old Time spark]

Hi all,

I am a new member so forgive any mistakes, but wonder if anyone can help advise me, I am a retired electrician doing a full renovation with a rewire of a property. I engaged an approved electrical contractor to carry out all wiring and installation of a whole house MHVR system.

Re the MVHR; (Vent Axia Kinetic) with three bathrooms in my home, the contractor only put one small semi flexible duct to each of the two wings (each extension has a bathroom and bedroom in it) I questioned how you can put warm dirty air from the bathroom, and then warm clean air into the bedroom down the same duct.

The answer was, 
As for the ventilation the fan that gets fitted in the bathroom have an external baffel and filter so that it cleans the wet air in itself and pushes the clean
air back through into the ducting system. Which is done at 2nd fix stage. I picked this system due to the complexity of running 2 additional pipes to
each wing, which cost wise on labour and ducting would be more expensive as well.

Am I wrong thinking this will not work right, how can cold air go down the same pipe as warm air is coming out of?

Paying several thousand pounds for this system alone I worry this will not give the efficiency promised. Suddenly I was informed after the roofer finished I needed to install vents in the slate roof, the electrician supplied these plastic vents but now says it an extra.

Onto wiring, so many parts I worry about, in my day you would never run low voltage cables (telephone, alarm, AV, etc) with ring main cables, supply cables, especially in the same holes, the answer is they are double insulated, and will not be an issue.
No cables are protected, and one even runs inside an old copper water pipe, where the ends have been hammered back, walls have been plaster boarded with no cables for lights, sockets cut out or marked.What point should first fix take you to now? 
Internal walls have cables run down to feed outside lights, which I am told will have plasterboard glued over with no chasing, fixing or even the cables flat. 
Outside lights planned to be below the PIR detectors, surly the heat from the down, up-lighters will trigger the PIR?

I am at a loss, while I know I am out of date now, I have no idea who to ask or turn to, wrote to NICEIC but no reply, have the regs changed that much, any suggestions would be appreciated or to be pointed in the right direction. 
I do not want to upset the electrician, sadly I have not  found where I can add photos to help explain.

Cheers

 

[ProDave]

You made the mistake of getting an electrician to fit an mvhr unit.  Yes he should connect the power to it but that is all.  It seems like UFH, there are a lot of electricians that don't have a clue about mvhr, so you should not trust them to install the ducting.

In short, the mvhr has one inlet taking air from outside, this passes through one side of it's heat exchanger, and then that supplies fresh air into every living room and bedrooom.

It then extracts air from every bathroom, kitchen and utility room, which again passes through the other side of the heat exchanger in the unit before being exhausted out of the house.

So you do only need one duct to each room, and some are fresh air supply and some are exhaust air removal.

There are 2 ways of piping the ducting, one is with big fat pipes that then branch off to each room, or the alternative (the one my house has) is the main supply and extract each goes to a plenum box, from where individual smaller ducts go directly to each room.

Do you have a pipework drawing of how the ducting was installed?

 

[Jono Pashley]

NICEIC won't help you there a bunch of self serving wasters who only get involved if someone's uses their logo without paying for the "privilege"

 

[Old Time spark]

Hi, Many thanks for your reply.

I did try to get the heating company to do the job, but waited a long time and never got the quote, so my fault for using the electrician, I guess also he has never fitted on before despite his assurances. He Had no idea about external vents, drainage, etc, the said he was fitting separate systems in the extensions, so I would have three systems in one small  house.

No sadly I have no plan of pipework, my confusion is with one small 3 inch pipe going onto the extension, how can this give the clean warm air to the bedroom, while at the same time take away dirty warm air from the shower room in the same pipe? 

Cheers

 

[ProDave]

It can't.

You can have 3 separate small systems but it would be unusual, it is far more usual to have one for the whole house.

I think you are at the point where you need to tell him to stop before the bodge gets any worse.  And don't let the other trades cover it all up with plasterboard yet until it is sorted out. Yes this will delay your project but that is better than getting it wrong.

It is actually a very easy DIY job. I did mine all myself and as an ex spark I am sure you have the practical ability to do it yourself.

Post the make and model numbers of the mvhr unit(s) you have.

Unfortunately you can;t as a new member post pictures, hopefully an admin member will read this thread and enable posting rights so you can post plans of your build.

I got all my ducting from BPC ventilation in NI they were the cheapest I could find and I am pretty sure they will design the pipe runs from your plans.

 

[Evans Electric]

I too am an Old time Spark although  I still work  a couple of days a week .     

I can't help with the whole house  vent system , read about them but never done one . 

With the wiring , things  have moved on a bit  since bending blocks & tallow fat.  Almost every job is now dry lined ...no one bothers with steel capping  ( sheathing)  anymore   ( except me)  .  The thinking is it won't stop a hammer drill so theres no point in fitting it . 

If your outside lights are pointing up at the PIR  it may be fooled into thinking it,s daytime  and stop working  .  

Telephone & alarm cable should not be run with 240V cables .  This has always been the case & as far as I know nothing has changed .    Yes the ring cables are  insulated & sheathed to ..is it 600V?  ,  but the low volt stuff isn't .   They shouldn't be there , as far as I know , unless they are insulated  to the same standard as the mains cables.

 Cable pushed down a copper pipe , not sure whats going on there TBH .

If as you say  ,  walls have been dry lined  , with the cables hidden ...either the sparks has the measurements  or he,s lacking in experience  or he,s stupid.  . ( He says, avoiding Forum Swear filter)  .   If we wire for downlights  we  put all the measurements  on a plan  , then tuck the ends up  to allow plasterboarding .    you don't want those eejuts  pulling the wires out  all over the place . 

No point asking the NICEIC  .  

 

[roys]

Was it not you Deke that made the clever suggestion several years ago about marking downlight positions on the floor with a plumb bob then once the ceiling was plastered over just reverse the procedure.

i liked that idea.

Apoligies if it was someone else's idea it was several years ago.

 

[kerching]

It may well have been me as that is my preferred mehod...makes a mess of the carpets though :slap

 

[roys]

Sorry Kerch

May have forgot who posted it but I didn't  forget the good idea

 

[SPECIAL LOCATION]

I am at a loss, while I know I am out of date now, I have no idea who to ask or turn to, wrote to NICEIC but no reply, have the regs changed that much, any suggestions would be appreciated or to be pointed in the right direction. 
I do not want to upset the electrician, sadly I have not  found where I can add photos to help explain.
 

NICEIC won't help you there a bunch of self serving wasters who only get involved if someone's uses their logo without paying for the "privilege"

No point asking the NICEIC  .  

NICEIC, ELECSA, NAPIT, STROMA  etc.. 

are all just trade associations that members choose to join by purchasing a membership they consider appropriate to their business model...

So... As there is no legal obligation for any contractor to be a member of any of them....

Unless a member has done something seriously contravening their membership rules they wont generally do much to upset any paying member...

If one customer is a bit unhappy about the quality of their members work..

Unless it is a serious life threatening danger, that is very likely to come back and tarnish their corporate image, there would be very little cost effective reason to investigate...

Any contractual gripes are between you and your electrician, possibly trading standards, (but hard to prove on a purely verbal agreement)

Logo misuse is easy to prove and has a high success rate if taken to court...

e.g. Company X claims to be a member by using our brands and logos...

But they are not and have never paid for member ship = easy to prove..

But gripes like....

Electrician said he would fit X Y and Z....  but actually fitted A B and C   and charged me more than I thought,  and took longer..  and was a bity messy..

A lot more time consuming and difficult to prove....  (so who pays the complaint investigation costs?)

AND...

if work is still in progress, unfinished it is quite hard to speculate what the finished product would actually look like..

So basically impossible to pursue complaints on unfinished work.

Back to your problems:-

1/ Do you have any written contract with a schedule of work and/or quote/estimate?

2/ Is this electrician a sole trader or just employee of a larger firm?

3/ What payment terms have you agreed?   if bits don't work do you still have some payments you can withhold to negotiate with?

4/ Do you have access to copies to the manufactures installation guide for this vent system... (lots of documents are downloadable nowadays)..

manufactures installation guide would probably answer a lot of your questions that you could then put to the installer if you think parts aren't right.

5/ Welcome to the forum... sounds like you could have a bit of a nightmare on your hands...  BUT..

Keep coming back onto this thread to update any further progress..

and the combined knowledge of US and YOU.. may be able to keep you grounded and just give a second (or third) opinion to bat your ideas and thoughts around..?

Guinness :Salute   

 

[Evans Electric]

Was it not you Deke that made the clever suggestion several years ago about marking downlight positions on the floor with a plumb bob then once the ceiling was plastered over just reverse the procedure.

i liked that idea.

Apoligies if it was someone else's idea it was several years ago.

Not me Guv'ner  but  I remember it  .        Ah  it was Kerch's  ...I'd have claimed it had he not posted . :innocent

 

[Evans Electric]

Keep coming back onto this thread to update any further progress..

and the combined knowledge of US and YOU.. may be able to keep you grounded and just give a second (or third) opinion to bat your ideas and thoughts around..?

I  second that   .   I'd like to bet your spark's low volt cables are not insulated & sheathed to the same standard as the mains ones . 

 

[Old Time spark]

Wow,

Thank you so much for the response, have to admit first time I have used a forum, but I am impressed.

Will answer as many questions as I am able,

Sadly I cannot do any of the work, which is very frustrating due to my poor health.

BPC was mentioned I did get a quote from them for the system / eq but I was unable to install it myself.

The planned MVHR unit is a Vent Axia Kinetic (model not been confirmed yet despite asking)

I have the Vent Axia  installation instructions but it covers the unit rather than the ducting, will take another look at them.

The Electrician is a small business, has about 6 staff I have insisted the boss did the job, following a poor experience with his lads when the old wiring was pulled out (while live) never in my life seen live wires dragged across a floor sparking!!

First fix was due to be completed August, invoice for that issued two weeks ago, paid 75% last week, withheld 25% pending another meeting. Not had confirmation of the final price. No specification, I made a list / spec three years ago of what I wanted, they just sent a mail back saying fine with a price.

Thanks for the confirmation I had not lost the plot, re the mains cables and alarm cables in the same holes, I am sure its just to save drilling a new hole, same with the using old copper water pipes, most would pull the old pipes out first or just do a new hole. (see photo link)

The electrician is registered with, MCS and NICEIC

 

[Evans Electric]

following a poor experience with his lads when the old wiring was pulled out (while live) never in my life seen live wires dragged across a floor sparking!!

Ah  I think I've met those guys ....was one's name  Roy Rogers and the other Hopalong Cassidy   by any chance .   

 

[phil d]

Ah  I think I've met those guys ....was one's name  Roy Rogers and the other Hopalong Cassidy   by any chance .   

Hmm, that brings back memories, lol

A number or years ago I was asked to help out a mate, he'd been self employed for years and had a good client base, however he'd been offered a decent spell of subcontract work at a large factory and had asked me if I'd cover his clients for him while he was busy. I was asked to go to one house to a report of a fusebox overheating, it was a rather odd setup, the house was in an exclusive area, and as you could imagine, rather expensive. The odd thing was the owners, the couple who'd bought it hadn't been able to afford it on their own so they'd bought it with an aunt and uncle who also lived there.

The overheating fusebox was caused by the uncle, they'd bought some kind of early jacuzzi and he'd just wired it into the already fully loaded box, iirc, there were 2 boxes, one doing sockets and lights and one doing an electric cooker, a hob, and a couple of showers, it was this one he'd wired the jacuzzi into. Anyway I sorted it, then a couple of months later I was called back by the niece, she was in a right state, it was about 6 pm, they were having a dinner party at 8, and they'd lost all the sockets, they went off after she'd plugged in a rather large hostess trolley.

I removed the socket and found it had been wired in a thin flex with a black outer sheath, in the back of the nearest socket along with 2 pvc cables, was an orange flex!

I removed a couple of wallboards to trace the cable and found a piece of white flex in the middle, it was at this point that we also made an interesting discovery, there was no plaster on the walls, just bare breeze block! It would go a long way to explaining why despite a very large heating system, the house was always cold.

It turned out that when they'd bought the house they'd decided to have downstairs done in those 8x4 wallboards, they were all the rage back then. The uncle, who'd been a woodwork teacher had done the job, and, in order to get a nice level surface had removed all the plaster, the wind just blew through the gaps in the blocks, hence why it was so cold. Well a couple of days later I'd gone back to fix the sockets and he was there, we got chatting and he asked if I had a nickname, I said the lads called me 'sparky phil' because of my job, "well, that makes sense" he replied, "unlike mine years ago, they used to call me TEX, and I never did work out why".

Maybe his mates had seen/had experience of his 'quality' work. lol

 

[Bruspark]

Was it not you Deke that made the clever suggestion several years ago about marking downlight positions on the floor with a plumb bob then once the ceiling was plastered over just reverse the procedure.

i liked that idea.

Apoligies if it was someone else's idea it was several years ago.

 .  . .  then plasterers make an unholy mess (sorry 'sound job')  and have to clean the floor before they get paid . .   Careful plan - in the van !!!

 

[kerching]

On one job.....all joists exposed before plaster boarding. I made a sort of Wild West style gallows affair. It had a plumb line 75mm from the 'noose end'. This was to allow for the 50mm clearance from surfaces.stand it on floor, noose end touches joist , spray paint blob on floor, move on to next

simples

 

[binky]

The Electrician is a small business, has about 6 staff I have insisted the boss did the job, following a poor experience with his lads when the old wiring was pulled out (while live) never in my life seen live wires dragged across a floor sparking!!

WTGrape - sounds like he's using brain dead labourers rather than sparkies

The electrician is registered with, MCS and NICEIC

MCS is for green tech like solar panels - irrelevent in this case.

video below may help, but it does sound like your electrical contractor is worth ditching?