Heat Recovery Ventilation - but house still stuffy

amadain17

After four years of humming and hawing we retro fitted a HRV system to our masonry built bungalow in September. The main motivation was air quality. I don't like opening windows - we lose all our heat and there are security concerns. The other issue was a fear of dampness as we gradually whack up the amount of insulation and make the house more air tight.

However I've very dissillusioned with it. I expected my house to feel fresh and airy. It isn't. Only marginally better than it was. As a result I still havn't blocked the external vents.

Also it is loud in the rooms with incoming air. It is like a fridge on its condensing cycle. Except it's constant noise, 24*7. In my lovely country home when I once had the joy of total silence.

Has anyone experience with HRV in bungalows? Is this as good as it gets or should I be going back to the suppliers?

Thanks.

Jumpy

Wait for your next electricity bill.
What is the backup heat system? Gas you might be ok, but our immersion system cost us 1500 every bill until it was removed.

They do not work unless your home is perfectly insulated.

amadain17

We don't use it for heating and it has no link to the immersion/hot water supply. For that we use a combination of oil/wood/solar. We put in the HRV for air quality. But the house isn't perfectly insulated - concerns about air quality and dampness have put me off. And in spite of my very expensive HRV system I remain concerned.

MicktheMan

amadain17 wrote: »

After four years of humming and hawing we retro fitted a HRV system to our masonry built bungalow in September. The main motivation was air quality. I don't like opening windows - we lose all our heat and there are security concerns. The other issue was a fear of dampness as we gradually whack up the amount of insulation and make the house more air tight.

However I've very dissillusioned with it. I expected my house to feel fresh and airy. It isn't. Only marginally better than it was. As a result I still havn't blocked the external vents.

Also it is loud in the rooms with incoming air. It is like a fridge on its condensing cycle. Except it's constant noise, 24*7. In my lovely country home when I once had the joy of total silence.

Has anyone experience with HRV in bungalows? Is this as good as it gets or should I be going back to the suppliers?

Thanks.

Hi Amadain,
we had a hrv system installed 2 years ago in our 30+ year old bungalow and have had an immediate improvement in air quality and no noise issues at all.
Mick

CJhaughey

Where is the unit mounted, attic or ground floor?
Are inline mufflers installed in the flow and return?
Are the pipes lagged and installed with resilient mountings?
What diameter pipes are the main feed and room feeds?
What settings do you have the room valves on?
Why are the wall vents not blocked? This negates the whole concept of HRV, the air will flow through the path of least resistance, if your house is sealed apart from the wall vents the unit will likely be sucking cold damp air through the wall vents.
What model is it?

PLIIM

amadain17 wrote: »

After four years of humming and hawing we retro fitted a HRV system to our masonry built bungalow in September. The main motivation was air quality. I don't like opening windows - we lose all our heat and there are security concerns. The other issue was a fear of dampness as we gradually whack up the amount of insulation and make the house more air tight.

However I've very dissillusioned with it. I expected my house to feel fresh and airy. It isn't. Only marginally better than it was. As a result I still havn't blocked the external vents.

Also it is loud in the rooms with incoming air. It is like a fridge on its condensing cycle. Except it's constant noise, 24*7. In my lovely country home when I once had the joy of total silence.

Has anyone experience with HRV in bungalows? Is this as good as it gets or should I be going back to the suppliers?

Thanks.

WE installed HRV in a bungalow a few years ago. Waste of money. We had all the problems you describe plus a higher electricity bill. We eventually turned it off and dont use it anymore. Spectacular waste of money.

amadain17

CJhaughey wrote: »

Where is the unit mounted, attic or ground floor?
Are inline mufflers installed in the flow and return?
Are the pipes lagged and installed with resilient mountings?
What diameter pipes are the main feed and room feeds?
What settings do you have the room valves on?
Why are the wall vents not blocked? This negates the whole concept of HRV, the air will flow through the path of least resistance, if your house is sealed apart from the wall vents the unit will likely be sucking cold damp air through the wall vents.
What model is it?

It's in the attic. Over the kitchen where noise doesn't matter.
I can't see any mufflers.
The pipes are solid and look well insulated and fixed. 100mil diameter.
The system runs on low/medium or 20minute boost. I run it constantly on medium and do the boost a couple of times per day. It is done centrally, not per room.
I figured the vents impact the heat recovery aspect, not ventilation and that filling them would worsen the situation. But maybe they are negatively impacting the air quality. I'll block them tomorrow and the cavity hole is being filled next week.
I'll PM the model.
Thanks.

mark2003

You should get an airtight test done on your house.If the result for the airtightness test isnt very good, well then the hrv will never work to a high efficiency.Also if you have solid pipes,you will hear alot more noise than the flexible pipes.

muffler

amadain17 wrote: »

I can't see any mufflers.

Fixed.












Sorry, couldn't resist

CJhaughey

mark2003 wrote: »

.Also if you have solid pipes,you will hear alot more noise than the flexible pipes.

Thats not really true, in fact flexible pipework is a lot less efficient than rigid, all the corrugations make a smooth flow almost impossible to achieve, thus a 100mm flexi pipe will only flow like a 80-90mm pipe which is quite a difference.
I have spiral wrap galvanised ducting and it is almost silent.
However my system has 150mm diameter ducting for the main supply duct, and the branches are smaller 110 or larger depending on what rooms are being fed.
Smaller for bedrooms and larger for living rooms.
Same on the extract side.
OP, I would try the system with the wall vents blocked off, this could be a lot of the problems.
Can you adjust the speed of extract and delivery independently?
If so it may be worth trying to run a slight underpressure in the house this is usually achieved by running the extract slightly faster than the intake.
If you imagine the air in the house is more humid than the outside air one problem is that you can force warm moist air into the buildings fabric, this is undesirable from a building and heath pov. The moist air can condense when it hits the cold surface and create problems with mould.
Have you contacted the supplier and told them the problems you are having?
It may be worth bypassing the installers and asking the makers.
My experience with HRV is that I would not now live in a house without it it makes a huge difference to the indoor climate and for almost negligible running costs.

amadain17

Thanks for all the replies. I'm going to move forward with insulation/air tightness. If the air quality does improve as a result of that I might be able move it to the low setting, where noise is less of an issue.

Regarding electricity bills - just checked our last one which was metered and no significant increase. It is higher but the main culprit is our heating - had a baby and now have the heating on much more, which uses a lot of electricity pumping the water around.

I really hope I won't be writing it off as a 'spectacular waste of money'.

gman2k

I think the lesson to be learned from all this is that Mech HRV systems should be designed and installed at design stage and incorporated holistically into the overall design.
IE, air tightness, high level insulation, personal needs and usage of the dwelling, location of main unit within dwelling etc.
Retro fitting MHRV into a dwelling that has not had the above considerations is asking for problems, and that's what you end up with.

10-10-20

I'd have to comment that if the HRV has been installed and the vents left open, it's also unlikely that other common sources of leakage have been treated either.
gman2k is of course correct, but I'd take this up with the installer as in my opinion you could debate whether the system is suitable for its intended purpose.