I am in the process of selecting an MVHR system for the house. Floor area is approx 260m2. I have quotes from BPC (competitive) and some other suppliers such as Regavent, Systemair etc. The units look pretty similar with comparable (claimed) performance parameters. I know Jeremy used Genvex for is build and some Mitsubishi models have been recommended also. Are there any no go makes/models?

 

• Does anyone have any opinions on performance or advantages/disadvanteges of wall mounted units over floor mounted ones?
• I have attached floor plans of the house. Please disregard the shown preferred position of the unit. An oil boiler has to go against the outside wall as well and I am a little bit concerned about the positioning on the inlet, extract and boiler flue all being on the 1.8m wide wall. I cant seem to find any definitive guidance on the minimum separation between these. Any thoughts?
• I am coming down in favour of a radial system but I have seen some drawings where runs of over 15m arent advised. Is this correct as I cant see how they can be avoided.
• I have also come across crossflow vs counterflow systems. Am I getting them mixed up?

I am in the same boat as you and hoping to make the decision this week or next so will be following this thread closely (similarly sized house (240m2 over 2 floors).

 

I’m more in favour of the radial system though one supplier is saying they are only better for a smaller house (this supplier is happy to provide us with trunk/branch or radial).  Anybody have a genuine link (as opposed to marketing from a company that only uses one type of ducting) to actual benefits or radial vs branch ducting? Or even experience they are willing to share?

 

I also need to look into the noise decibels each system makes although we plan to put ours in the roof space above the hall way so not sure how significant this will be?

 

We’re also going to install the system ourselves to save a few pounds.

We have the Ecocent Air from Earthsave and it is working really well, it offers the same heating and cooling functionality as the genvex, is quiet and easy to use, we have been running it 3 months now with no problems. They did a full supply and install for around the same price as buying the genvex from a U.K. Supplier on supply only. 

I think Jeremy has stated a few times now that if he were to do it again he wouldn't pay the extra for the Genvex.  More than likely just get a good solid MVHR unit and then a much cheaper AC unit for cooling when/if required.

 

I personally like the radial ducting system as its a much easier DIY install.

Jeremy also stated that he can cool his slab by reverse engineering the ASHP and it works well ( I plan to do the same) 

Any thoughts on the Airflow BV400 or DV145 or Vent Axia Sentinel B units?

We are currently installing our MVHR. Its a radial 75mm pipe system with a Vent Axia Sentinel Plus - our floor area is about 230m2. It's not working yet so I can't vouch for its quietness. It was supplied by BPC - highly recommended.

 

The ducts seem to go in easily if you have posi-joists, but you need to plan the routing carefully to avoid too much overlapping. The unit is in a separate sound-insulated cupboard off the landing, so it's fairly central.

 

Looking at your plans, you are likely to need more space for the ductwork than you've shown, but these could be boxed into the corner. The SVP next door is a plus for the condensate drain. I presume the vents will be vertical through the roof - you'll need to get 1500mm separation between supply and extract.

I spent a few hours at Earthsave products in Wallingford yesterday going through the options for my MBC build. They have an Ecocent Air in the showroom that you can see working. 

This will be my system of choice as it can pre heat or cool the air. It can manage up to 500m (i think so will be more than capable for my 300m house

It is big so make sure you have room

 

Speak to Nick at earthsave he is really helpful

RandAbuild - 

 

I have a quote from a company called Systemair (Swedish) which is only marginally more (10%) than those from BPC. I have seen Systemair units and they look very well built. They also offer a number of features that appear as chargeable options on the units that BPC supply. The only thing  is that they have specced a branch system rather than a radial one. I am going into investigate this one some more but frankly I am getting to a point of analysis paralysis and might just buy the nicest looking one

 

The position shown on the drawing is incorrect and will be shifted over to the left hand corner of the wall so that both vents will sit inside the 1750 room width.

I think the proof of the Ecocent system will be how it works in the middle of winter.

The Ecocent Air is their MVHR not the DHW cyclinder that we have as well, the Ecocent Air is the same as the Genvex MVHR that offers built on cooling and heating within the unit.

Edited October 12, 201610 yr by Mikey_1980

Oops, sorry.  I thought that product was one that used outgoing air through the MVHR to extract energy for DHW.  I stand corrected! 

Its easy to get confused with the Ecocent naming.  On another note, no heating and no temperature drops and plenty of hot water with the Ecocent for DHW.

 

The whole house is a steady 22 degrees all the time with the exception of one bedroom which reaches 25 in the late afternoons with the low sun, but it isn't uncomfortable, and will improve once we get some curtains in.

I am about to order an Airflow Adroit DV96 EPH from BPC for a 96m2 well insulated house.

It seems to tick most of the boxes at a fair price.

 Auchlossen, just wondering how you got on with the Airflow Adroit? Looks tempting, seems to be one of the few in that price range that networked / cloud control...

Adroit is installed and fully 'plumbed in' but not yet up and running. It will be a while....

@Auchlossen I'm keen to hear how you got on with the Airflow unit?