Green Building Forum - Want to see inside an 8 year old MVHR?

Want to see inside an 8 year old MVHR?

djh — Tue, 20 Feb 2024 08:52:27 +0000

Ours has been there for nearly 8 years now. No signs of anything worrying yet, though I think it's a little noisier so I think there may be some dirt on the fan blades.

Want to see inside an 8 year old MVHR?

borpin — Tue, 20 Feb 2024 15:48:01 +0000

Posted By: djhthough I think it's a little noisier so I think there may be some dirt on the fan blades.

For me, the noise was the bearings failing.

Want to see inside an 8 year old MVHR?

djh — Tue, 20 Feb 2024 16:35:35 +0000

Yes, ours doesn't sound like bearing noise to me.

Want to see inside an 8 year old MVHR?

cjard — Wed, 21 Feb 2024 07:29:15 +0000

The pipes aren't that bad it seems; I don't care about the exhaust (though maybe if it fills to be chock full of mould one day I will) and the inlet is only a few feet long and clear. From the house there is a bit of dust but generally quite good

I'm sure I recall seeing some sort of foam balls you can put through the ducts, after attaching a high power fan, that clean them out.. I'd probably just try a high power fan to start (sucking through the pipes rather than blowing; wouldn't want a pressure buildup to pop a duct off a manifold or plenum behind a plastered ceiling..

Have ordered a manometer that does humidity and temp too so will do some experimenting on the balance and humidity at some point to add a bit of science to the efficiency musings

Want to see inside an 8 year old MVHR?

GreenPaddy — Fri, 23 Feb 2024 22:16:22 +0000

As filters block, the flow rates change, and so MVHRs go out of balance (unless you paid extra for a constant flow rate unit - like a Paul, which I think DJH may have??)

My unit of 14 year vintage (prob just cursed it) was supplied with temp displays for the 4 connections, and I use that to occasionally alter the fan speeds to correct the balance. I fit temp sensors to all the units I fit for clients, so they can do the same, as I've not found a unit since, with built in temp sensors.

Also had a client with a VA Sentinal plus, like cjard's, and their cond drain also blocked, but eventually leaked out through the unit. The drain was quite a small tube. Was running like a paddle steamer, fans inch deep in water.

My regular chore is to ensure the fans are put to max speed regularly, as condensate hangs up in the pleated heat exchanger. I run my unit at low "normal" speeds, which doesn't force the condensate out. It can hold up about 1/2 litre of water.

Want to see inside an 8 year old MVHR?

djh — Sat, 24 Feb 2024 11:17:20 +0000

Posted By: GreenPaddyunless you paid extra for a constant flow rate unit - like a Paul, which I think DJH may have??

It's a Brink, but otherwise yes. Constant flow rate (a.k.a. volume) is one thing you pay for, and better airtightness etc.

Want to see inside an 8 year old MVHR?

wookey — Mon, 26 Feb 2024 04:04:28 +0000

I had a look inside mine last year and it was pretty mouldy and horrid on the 'world' side, particularly in the exhaust fan section. It had been running (daytime only) for about 8 years. I think it's permanently quite cold and humid there so mould does tend to grow. I know someone else with the same model as me (Itho Eco 4 HRV) found the PCBs on the back of his motors corroded in that environment. - mine seem fine.

Want to see inside an 8 year old MVHR?

borpin — Mon, 26 Feb 2024 07:42:26 +0000

Posted By: GreenPaddyI fit temp sensors to all the units I fit for clients, so they can do the same, as I've not found a unit since, with built in temp sensors.

My old helios unit did and so does my Komfovent unit (all except exhaust which I'd not noticed before). I read these sensors via the TCP MODBUS interface. Perhaps I'll fit an exhaust one just for the hell of it!

Want to see inside an 8 year old MVHR?

Simon Still — Mon, 26 Feb 2024 11:23:10 +0000

>>I'm sure I recall seeing some sort of foam balls you can put through the ducts, after attaching a high power fan, that clean them out.. I'd probably just try a high power fan to start (sucking through the pipes rather than blowing; >>

the balls sound like a good idea - I tried cleaning out our room ducting when we redid the final connections to the MVHR - opened the distribution boxes, and used a domestic vacuum on each of the pipes. not convinced it did much .

Want to see inside an 8 year old MVHR?

Simon Still — Fri, 05 Apr 2024 10:13:37 +0100

Going back to the original poster - how did you remove the fan? I cant' access the side of my unit as it's installed - it looks like you've taken the side off the case.

I opened mine (VA Kinetic - same unit) up yesterday (similar age - about 8 years) and it was generally black like that (which I think is a mix of mould and city air dirt) But there were also LUMPS of mould growth on the fan blades (rather than an even covering). I gave it all a good clean (water/toothbrush/cloth/bleach spray and rinse) and flushed through the condensate drain with a lot of water/bleach solution/water.

the issue I had was that water pooled under the fan - most of it drained (if I poured a half litre bottle through) but enough left afterwards that I could hear the airflow disturbing it. in the end I push a cloth through between the fan blades and soaked it all up but that area doesn't seem to drain very well and I can't see any way of getting to it.