MVHR DIY install in Loft Conversion

[alex3060]

Hi All, 

 

I live in 1950’s First floor Maisonette with Loft conversion which started 4weeks ago. I have previously not known about MVHR system and didn’t take into account in designs however due to loft of condensation in current floor bathroom and kitchen and lot of heat loss, i thought to add MVHR in my Loft in a corner. 
 

I have contacted BPC and received Full Ventilation guide with design attached here. I want to install it myself or with current builders and want to make sure the installation is done correctly. I spoken with builder's who said they have not installed one before but if ‘can do it’ is the reply i got. I have seen great advice in this forum and i am looking for any posts with links that previously had been discussed which has step by step installation guide? 
 

Also, as i have not thought about this MVHR installation previously, do i need to need to cut through joists for 75mm radial ducting to go though? and will this compromise any structural integrity of loft floor? I am also attaching list of materials supplied by BPC which should be receiving next week.
 

Please let me know if any materials i need which are not in this list ex: how to add or which humidity sensors to MVHR system. 
 

Your advice will be greatly appreciated. Many Thanks in advance.   

BPC-8287773257 - Rama Krishna FULL Rev 01 FF-SF.pdf

[JohnMo]

If your pretty airtight go that route otherwise...

 

My view is dMEV done well or MEV. Both working conditional demand - CO2 and or humidity, with self actuating air inlets either through wall or trickle 

 

 

Video 

https://youtu.be/CGP_1rsOzDI?si=37tNvRjRVN1sBFNQ

[alex3060]

@JohnMo Yes, i am also emphasising on airtightness for this Loft conversion. All parts for MVHR are ordered would be delivered next week. Any pointers/links for full installation steps? 
 

Many Thanks

[alex3060]

Hi All,  

 

Any advice is greatly appreciated for step by step installation by myself for MVHR in my Loft which is in build stage as i have few more questions from my original post. I have had all materials delivered today and hoping to do the installation with my friend who is helping me over coming weekend. Sorry for long post. 
 

I have installation guide from BPC website but want to make sure i cover all aspects of installation except electrical work and connecting condensation drain to another drain pipe. In full design i provided in my 1st post, we will have a small bathroom next to cupboard where MVHR is going to be located. Is it ok to connect condensation drain pipe to waste pipe in loft bathroom? 
 

I spoke to builder and quoted i was £3000 for installation without materials. However, i may need builder to connect drain pipe to loft bathroom waste pipe.

 

Do i need to complete electrical connections for any controls before MVHR unit installation? as i thought i read somewhere this is the process. I have no idea about electrical stuff. Also, am i correct in saying all ducts need to be covered until MVHR is switched on after loft and current floor renovation to avoid dust getting into unit? 
 

Finally, my property is going to be around 95 m2 once Loft is complete. Please, can someone provide me calculations for how much extract and supply ventilation levels in l/s which meets BC regulations (should the levels be a bit more than minimum BC regulations in Approved document F?) and have around 50-55% efficient (is this number correct?) operating capacity for MVHR unit and to come on Boost mode if there is too much humidity in kitchen/shower area? BPC has mentioned in my contact with them in last 2 weeks as 22l/s. I will follow up with them this week if this is for one particular room or for whole house. How do i calculate how

many ACH for a family of 4 with 2 young kids in a 95m2 first floor maisonette? 
 

Also, it is greatly appreciated if my OP questions can be addressed?
 

Sorry for long post and Many Thanks in advance🙂 

[alex3060]

Edit: * I was quoted

Edited February 11 by alex3060
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