Air tightness questions

Rockefellers

Hoping someone can help me out with the question below.

I moved into a house built in 2013 which has air vents on the wall. They let in too much noise for my liking so I am considering making the house air tight and installing a decentralised hrv system.

My Ber is as follows
B1 89.42 (kWh/m2/yr)

According to the Ber report the only things to improve are the open fireplace and the wall vents which let out heat, and they said part of the door area had a uv value of less than 2.7 and more than 2, which could be improved. I'm not sure if they meant the front door or back door area as it wasn't specified.

So I'm Planning to put in a stove at the fireplace and sealing cracks around Windows/doors etc. But could I get away with not replacing the door?

Also for the air tightness test, should I get an nsai certified company for that or does it not matter? How much should the test cost? Any help much appreciated.

B-D-P--

Only small issue I see is carbon monoxide poisoning, a stove in a airtight house needs no have an external feed.

murphaph

B-D-P-- wrote: »

Only small issue I see is carbon monoxide poisoning, a stove in a airtight house needs no have an external feed.

And attention needs to be paid to the hrv and hob extractor to make sure no dangerous vacuum can arise, pulling exhaust gases into the living space rather that letting them escape up the chimney.

mike_2009

Agree with all the above
slight positive pressure in room with stove to prevent fumes entering room. Get a recirculation extractor hood?
is there natural gas in the house? Could that be why vents are there?
CO/CO2 detectors for sure
your first air tightness test is going to reveal a lot of leaks you didn't expect, window seals, gaps in walls etc, smoke stick should help identify them - get these on amazon in advance
if blocking the chimney do it top AND bottom
as you're not going for any certification, anyone who has the equipment can do the air test, you'll most likely need the first to identify key areas to work on after this and then perform the second test to ensure your changes worked.

Get wide diameter pipes for the air to flow silently, watch out for the design, should be radial, i.e. one whole pipe for each room or you'll hear noises transmitted between rooms down the common air pipes! The HRV installer should have air flow gauges and balance the system, check their experience and references closely. Then leave it on all the time and see how it goes.....

Calahonda52

decentralised hrv system.

?

Rockefellers

I will be getting a room sealed stove which will have an external air supply, will have co alarms put in also.

Rockefellers

Looking to get something like the freshr ductless/filterless hrv system or else the lunos one.

mike_2009

you'll need to check for sufficient airflow under internal doors and the freshr may require two systems at either end of the house to create the necessary flow. I think freshr were working on a system with minor ducting extensions.....
Ideally a ducted system would work better, seal off the ducts until you're ready to test as any construction dust etc if it settles in the ducts will get noisy when turned on!

Rockefellers

I thought th freshr system has a unit in each room?

I definitely can't get a traditional hrv system as it would mean tearing up the house and losing a good bit of space for the ducting, I can't justify that cost.

But from what I have read decentralised units are better anyway, they are cheaper to run, payback in 8 years compared to around 50 years with traditional hrv. With decentralised hrv you don't have to replace filters every year. You don't have to get the ducting professional cleaned as there is none so more savings there. The units are quieter than normal hrv also. I don't think there is a single advantage of traditional hrv over decentralised hrv but open to correction?

cyfac

Finished my new build in July air tightness super insulated triple glazing air tight value of .78 (wasn't aiming for passive) built a dormer so i was actually advised to use a decentralised system all i can say is there fantastic i have vents in all habitable rooms and wet rooms with a centralised control panel which allows me to adjust as required my only mistake was putting in a heat system (heat pump) absolutely no need as i write this the house is like toast with lovely fresh air feel to it.

Rockefellers

That's great to hear. What's the brand name of your system?

cyfac

Rockefellers wrote: »

That's great to hear. What's the brand name of your system?

PM sent

Paul Kiernan

Rockefellers wrote: »

That's great to hear. What's the brand name of your system?

I'm curious too. I'm not sure what you mean by decentralised system with vents in each room and a centralised control panel. I'm torn between standard system with ducting and something like the Lunos/FreshR solution.

BryanF

Paul Kiernan wrote: »

I'm curious too. I'm not sure what you mean by decentralised system with vents in each room and a centralised control panel. I'm torn between standard system with ducting and something like the Lunos/FreshR solution.

Decentralised systems are for retrofits. Aren't you building a new house? What has your ber assessor put in the provisional BER

cyfac

BryanF wrote: »

Decentralised systems are for retrofits. Aren't you building a new house? What has your ber assessor put in the provisional BER

Thats not true mine was a new build with decentralised units spec'd from the start this meant there positioning was determined before blockeork began and thermal insulated housing units were fitted by the blocklayers in place of blocks with the units following afterwards air tightness was applied both intetnally and externally to these units so as not to comprimise the air tightness of the house overall

BryanF

cyfac wrote: »

Thats not true mine was a new build with decentralised units spec'd from the start this meant there positioning was determined before blockeork began and thermal insulated housing units were fitted by the blocklayers in place of blocks with the units following afterwards air tightness was applied both intetnally and externally to these units so as not to comprimise the air tightness of the house overall

Any drawings of these units positioned by the bricklayers? How larger an ope was required?

cyfac

BryanF wrote: »

Any drawings of these units positioned by the bricklayers? How larger an ope was required?

Ope was 10inches square and units had to have a minimum of 8 inches in clearence from any obstruction eg internally ceiling or internal wall and externally facia and soffit also units had to be a minimum of 1.2metres apart

Paul Kiernan

BryanF wrote: »

Decentralised systems are for retrofits. Aren't you building a new house? What has your ber assessor put in the provisional BER

I'm building a new extension to the rear, rebuilding/refurbishing an existing extn to the front and doing minimal changes to a 100 year old cottage which will be between the two extensions. The cottage and front will house bedrooms/bathrooms and is probably suited to a standard MHRV system with short duct runs. The rear extn will be mainly open plan living space and might work best with a decentralised unit at each end working in tandem. That leaves the utility room (which will be used to dry clothes!) needing some form of ventilation, maybe DCV or humidity controlled "single room HRV".

ninganick

cyfac wrote: »

Finished my new build in July air tightness super insulated triple glazing air tight value of .78 (wasn't aiming for passive) built a dormer so i was actually advised to use a decentralised system all i can say is there fantastic i have vents in all habitable rooms and wet rooms with a centralised control panel which allows me to adjust as required my only mistake was putting in a heat system (heat pump) absolutely no need as i write this the house is like toast with lovely fresh air feel to it.

Hello,

Looking into the ductless freshR system and I'm wondering if you had any problem with BER assessment?
You also mentioned no need for a heat pump, is that still the case? Will be aiming for passive House standard.
Thanks

ht9zni1gs28crp

cyfac wrote: »

Finished my new build in July air tightness super insulated triple glazing air tight value of .78 (wasn't aiming for passive) built a dormer so i was actually advised to use a decentralised system all i can say is there fantastic i have vents in all habitable rooms and wet rooms with a centralised control panel which allows me to adjust as required my only mistake was putting in a heat system (heat pump) absolutely no need as i write this the house is like toast with lovely fresh air feel to it.

How would you heat the house without a heatpump?