No heatpump, HRV or underfloor on a new build

ArraMusha

I'm at the construction drawing phase of a new build and before I sit down with my Engineer I would appreciate any feedback on the below item.

I'd prefer not to install a heat pump and would like to stick to the older reliables of oil, radiators and a wood burning stove. I realize that part L of the building regulations make it mandatory to install renewable forms of heating, like solar or photovoltaics, but if the insulation is to a very high spec over the complete envelope how can I find out at this stage what are my options for renewables, with this setup?
The house is 208 sqm., Windows to A3, 150mm floor insulation, 250mm cavity.

Also, if I don't install an airtight membrane and don't seal the windows,doors etc. and don't install a HRV system, besides air tightness and air exchanges per hour are there any other compliance issues that need to be considered?

It is well documented that HRV systems provide clean warm air and reduce energy loss and are of benefit to asthmatics.
The two issues I have with HRV are 1)Most of the work they do (cleaning and warming inhaled air) should be done by the nose and respiratory system. 2) The can cost anything form 4-6k.

Thanks for reading and posting comments.:)

893bet

Get a prelim BER done. It will tell you what u need renewables wise.

Airtightness and some kind of mechanical ventilation is a must. Not even sure if regs can be meet with hole in the wall vents.

ArraMusha

Thanks 893bet. I'll get the theoretical BER done to see what renewables are needed.

There is a mechanical type vent (no fan) that I heard about which allows high winds to be blocked and disperses air over the surface of the walls. Not sure who the manufacturers are or the customer satisfaction with these?

sydthebeat

ArraMusha wrote: »

I'm at the construction drawing phase of a new build and before I sit down with my Engineer I would appreciate any feedback on the below item.

1. I'd prefer not to install a heat pump and would like to stick to the older reliables of oil, radiators and a wood burning stove. I realize that part L of the building regulations make it mandatory to install renewable forms of heating, like solar or photovoltaics, but if the insulation is to a very high spec over the complete envelope how can I find out at this stage what are my options for renewables, with this setup?
The house is 208 sqm., Windows to A3, 150mm floor insulation, 250mm cavity.

2. Also, if I don't install an airtight membrane and don't seal the windows,doors etc. and don't install a HRV system, besides air tightness and air exchanges per hour are there any other compliance issues that need to be considered?

3. It is well documented that HRV systems provide clean warm air and reduce energy loss and are of benefit to asthmatics.
The two issues I have with HRV are 1)Most of the work they do (cleaning and warming inhaled air) should be done by the nose and respiratory system. 2) The can cost anything form 4-6k.

Thanks for reading and posting comments.:)

1. as above, the only way to know what specification you need to build is to get a preliminary BER (DEAP) assessment done. The minimum required insulation levels are already at a "high level"

2. the problem here is that the lack of air tightness effects every other specification.... in that if you build a house to worst acceptable air tightness, you will have to upgrade all your other elenments to supplement this.. which means more solar required, higher insulations levels, better windows etc.

3. as above, if you dont use a MHRV system, you must upgrade all other elements.


this will all become very clear to you when you sit down with an assessor and see what knock on effects your choices make.

ArraMusha

Thanks 'sydthebeat' for your feedback !

mfceiling

Not bothering with airtightness is like buying a coat but only putting on one arm and not zipping it up.

ArraMusha

mfceiling wrote: »

Not bothering with airtightness is like buying a coat but only putting on one arm and not zipping it up.

I hear you 'mfceiling', and in keeping with you analogy the point I'm making is its ok and possibly healthier not to zipp up the coat, and to eat more instead.

Long term living in a bubble (air tight house) is just something I'm not comfortable with, but I'm open to being convinced.

sydthebeat

ArraMusha wrote: »

I hear you 'mfceiling', and in keeping with you analogy the point I'm making is its ok and possibly healthier not to zipp up the coat, and to eat more instead.

Long term living in a bubble (air tight house) is just something I'm not comfortable with, but I'm open to being convinced.

well taking the extreme example, they dont seem to have a problem with it in the international space station... and thats as 'air tight' as you can get
submarines as well are designed for exterem air tightness

i think the perception that an 'airtight' house is a 'bubble' is an incorrect one.

what we try to do is design out the 'uncontrolled' or 'unintended' air leakage from a building and leaving the controlled and designed air inflows.

Drift

ArraMusha wrote: »

Long term living in a bubble (air tight house) is just something I'm not comfortable with

That's why you put mechanical ventilation inn the house - to ensure that it is a well ventilated bubble.

Designed ventilation is targetted at the correct areas delivering appropriate volumes of fresh air to specific points and removing fouled/less healthy air from cooking areas, toilets, etc.

Your approach is to hope that by doing a less tidy build the air leaking in and out of the building (which varies based on the prevailing weather conditions and the degree of how untidy you've been in your build) will provide appropriate healthy air supply to correct locations and remove poor air elsewhere. It might work - but more than likely it won't and you'll end up with dead pockets and draughty pockets.

Why spend all that time designing a brilliant layout for your house and not put time into designing how to make it comfortable and healthy?

overshoot

ArraMusha wrote: »

It is well documented that HRV systems provide clean warm air and reduce energy loss and are of benefit to asthmatics.
The two issues I have with HRV are 1)Most of the work they do (cleaning and warming inhaled air) should be done by the nose and respiratory system.

I think you misunderstand the best effects of HRV here, yes the extra air changes will remove slightly more dust from the air but it also removed a lot more carbon dioxide/monoxide etc and gets the most oxygen in the air you breathe.... short of a mutation your nose wont do that!
Its not just warming the air for inhalation, think hands & feet. You said yourself you want oil, which costs money, presumably to heat your rooms/the air in them? Why let the heat seep out of the house? Its more efficient/cheaper in the long term to transfer it from one area to another than create it from scratch.

With this type of build, it is only airtight where you cannot control the airflow. The rooms have a constant supply of fresh air (more than your old trickle vents) with the heat recycled from the escaping air rather than lost for good.

Metric Tensor

I have found modern houses (i.e. last 5-10 years) that rely on trickle vents alone feel stuffy.

I don't know is there any measured scientific data to back this up.

galwaytt

ArraMusha wrote: »

I hear you 'mfceiling', and in keeping with you analogy the point I'm making is its ok and possibly healthier not to zipp up the coat, and to eat more instead.

Long term living in a bubble (air tight house) is just something I'm not comfortable with, but I'm open to being convinced.

As syd says, an airtight house is not stuffy at all. This is a common misconception. Airtight is a reflection of quality of build, it is not a measure of/if the building is ventilated, nor how.

MightyMunster

Makes no sense not to go airtight with MHRV. Would have thought it's a no brained. Saving thousands in heating costs and more importantly a comfortable, dry house to live in. Having lived in many old, draughty, damp and cold houses/flats anyone that wants to go back to condensation on Windows, mould, etc is mad!

Falcon L

Two and a half years ago we were building our new house. We knew what we wanted it to do for us and we were prepared to make a stand against the conventional beliefs that you see above.

I know that MHRV delivers fresh air into the house, but it's not the same coming out of a vent in the ceiling as it is coming in through an open window. My wife and I have always been fresh air fiends and the windows are always open, day and night. This was always going to be a problem with an MHRV system. We weren't prepared to live with closed windows, period.

What we ended up with is a very well insulated house, similar to what you describe in your OP. Oil heating that never gets used. We got 500L of oil delivered 2 years ago and most of it is still in the tank! The stove takes care of our heat needs and we have an endless supply of free logs.

The water is heated by a stand-alone unit with a small air to water heat pump built into it. We have 270L of very hot water available all the time (even when we had 6 adults and 2 children staying with us for a couple of weeks) The cost for this hot water worked out at €105 (measured) for the year 2014. We are on course for a similar cost for 2015. We could add a solar collector to this system but the savings would never justify the cost.

We may not conform to the gospel, but we scraped an A3 BER. We've never felt uncomfortable in the house and stuffy it aint. :cool:

Metric Tensor

Falcon L wrote: »

We've never felt uncomfortable in the house and stuffy it aint. :cool:

This is a fair point. If you're the type of person who will have the windows open in the middle of December then MHRV is not for you.

A good regime of purge ventilation using windows and cross-flow is adequate for ventilation.

Obviously a lot of heat escapes when you do this so if you were heating the house to the same temperature as other people who don't open windows as often you will spend more on heat. Of course if you like the windows open you probably don't like the temperature as high as other people!

ht9zni1gs28crp

Makes no sense whatsoever, why put all that expense of Insulation in only to heat the air then watch it piss through the fabric?

If 4-6k on a MHRVC system bothers you now wait until the quote comes in to fill that 250mm cavity.....

BarneyMc

My advice is to go with the air tightness route. Air leakage can vary considerable - you could end up with a house that's ventilated naturally just to your liking but that's very unlikely - you'll probably end up with a very draughty house and you'll be spinning the roulette wheel when it comes to seeing how well your insulation works in practice.

Metric Tensor

To add to my previous post re using windows regularly for purge ventilation -

This is still no reason not to have good air-tightness details. Just because you are using the opening sections of your windows to ventilate that is no reason to allow air to leak in and out around every penetration and junction in the wall!

Falcon L

Metric Tensor wrote: »

To add to my previous post re using windows regularly for purge ventilation -

This is still no reason not to have good air-tightness details. Just because you are using the opening sections of your windows to ventilate that is no reason to allow air to leak in and out around every penetration and junction in the wall!

Yep, it wouldn't make sense to build without air-tightness. My house is built to air tight standards... apart from the big holes in the walls.

Metric Tensor

Falcon L wrote: »

Yep, it wouldn't make sense to build without air-tightness. My house is built to air tight standards... apart from the big holes in the walls.

Which, of course, are covered over for the air-tightness test!

ArraMusha

Thanks for your post 'falcon l'. A number of very Interesting facts in your post. Mainly that you referred to the conventional methods which most new builds are following ie. High insulation leads to air tight, leads to HRV.....

Also interesting was the low heating cost, thanks for sharing, and I assume the relatively low upfront costs for oil and stove. Also you mention that your house is not stuffy and i doubt there is any black mold.
Sounds like this is the heating system I'll be going for with some PV's for part L. As regards ventilation I'm looking at a mechanical system that fits over the hole in the wall.
That mini heatpump that just heats your hot water sounds interesting...must look into that also. Heatpump technology is impressive and the theory is sound. Its the upfront investment cost of a larger system that is prohibitive right now.

ht9zni1gs28crp

ArraMusha, go and have a look at NZEB Open day and go visit a low energy example. It will convert you and restyle your way of thinking..

ArraMusha

miller_63 wrote: »

ArraMusha, go and have a look at NZEB Open day and go visit a low energy example. It will convert you and restyle your way of thinking..

Not convinced based on the above. Just met another heatpumper today sorry he ever installed it. Seems like we're at the stage where the bad experiences related to heatpumps and hrv are being resolved but we are not there yet. I'm all for the "latest and greatest" but on this one oil and stove and mechanical vents wins over conventional systems, sorry ladz.

Having said that I'll be firing in pipes for a heatpump as the jury are still out
...drinkin tay... all the best, and cosy homes to everyone.

ArraMusha

miller_63 wrote: »

ArraMusha, go and have a look at NZEB Open day and go visit a low energy example. It will convert you and restyle your way of thinking..

Not convinced based on the above. Just met another heatpumper today sorry he ever installed it. Seems like we're at the stage where the bad experiences related to heatpumps and hrv are being resolved but we are not there yet. I'm all for the "latest and greatest" but on this one oil and stove and mechanical vents wins over conventional systems, sorry ladz.

Having said that I'll be firing in pipes for a heatpump as the jury are still out
...drinkin tay... all the best, and cosy homes to everyone.

893bet

ArraMusha wrote: »

Not convinced based on the above. Just met another heatpumper today sorry he ever installed it. Seems like we're at the stage where the bad experiences related to heatpumps and hrv are being resolved but we are not there yet. I'm all for the "latest and greatest" but on this one oil and stove and mechanical vents wins over conventional systems, sorry ladz.

Having said that I'll be firing in pipes for a heatpump as the jury are still out
...drinkin tay... all the best, and cosy homes to everyone.

There are loads of people with MVHR and/or heat pumps who are very happy.

You are choosing to listen to the opinions that back up what you want to do.

Get your DEAP done then you will k ow what you can and can't do!

ht9zni1gs28crp

I think your mindset isn't for changing given what your listening to and not paying heed to what we are telling you.
'Not convinced based on the above'' statement in response to an event that hasn't even happened yet?

An event that may take three hours of your time on a Saturday or Sunday which you aren't prepared to do...yet could effect the standard of your living for the next thirty years.



A wise man has open ears....

BarneyMc

ArraMusha wrote: »

Not convinced based on the above. Just met another heatpumper today sorry he ever installed it. Seems like we're at the stage where the bad experiences related to heatpumps and hrv are being resolved but we are not there yet. I'm all for the "latest and greatest" but on this one oil and stove and mechanical vents wins over conventional systems, sorry ladz.

There will always be bad examples. What airtightness and insulation levels did this lad achieve? Or did he just 'stick in' a heat pump?

You are choosing the system with the intrinsic poor performance based on the fact that 'it works' rather than the system that will give you a much better performance unless commissioned incorrectly.

Build with your house in mind in 10 years time rather than 10 years ago.

sydthebeat

Reminds me of a guy i know who installed a geothermal heat pump system into a house with rads and natural ventilation, and then gave out about how high his electricity bills were.

Metric Tensor

I'm going to buck the trend a bit here -

On some of the new houses I recommend high efficiency condensing oil fired boilers with rads rather than heat pumps. When I discuss with the client how they propose to live and what they expect from a heating system I often find that their proposed lifestyle is not best suited to a heat pump / uf lifestyle.

It's amazing how little oil is actually used to keep a new house warm, particularly when coupled with appropriate thermal mass and a good MHRV system.

I always require good air-tightness detailing from the contractor and I always recommend MHRV. (Sometimes the clients don't agree regarding MHRV and if so we look at alternatives!)

cyfac

Metric Tensor wrote: »

I'm going to buck the trend a bit here -

On some of the new houses I recommend high efficiency condensing oil fired boilers with rads rather than heat pumps. When I discuss with the client how they propose to live and what they expect from a heating system I often find that their proposed lifestyle is not best suited to a heat pump / uf lifestyle.

It's amazing how little oil is actually used to keep a new house warm, particularly when coupled with appropriate thermal mass and a good MHRV system.

I always require good air-tightness detailing from the contractor and I always recommend MHRV. (Sometimes the clients don't agree regarding MHRV and if so we look at alternatives!)

Hi all

Im going to go with tensor on this one we built our house with the emphasis on high spec insulation air tightness HRV and high spec TG glazing we were lucky our site was south gacing and the architect laid out the house so all habitable rooms were south facing our architecht advised by going this route we would only need a mimimum amout of heating and as such a good condenser boiler with rads would suffice spend the money in the insulation hrv etc he advised and he was right i half filled the tank 3 years ago and its still over a quarter full

JimmyMW

ArraMusha wrote: »

Not convinced based on the above. Just met another heatpumper today sorry he ever installed it. Seems like we're at the stage where the bad experiences related to heatpumps and hrv are being resolved but we are not there yet. I'm all for the "latest and greatest" but on this one oil and stove and mechanical vents wins over conventional systems, sorry ladz.

Having said that I'll be firing in pipes for a heatpump as the jury are still out
...drinkin tay... all the best, and cosy homes to everyone.

I am afraid that "new" technology like heat pumps etc get a bad name due to a number of different factors

1. The designer has not got a clue and does not consider a house as a whole, they often do not pair the heating system with the building fabric or other systems, ie thermal mass (Concrete Block with external or cavity insulation) ideally requires a constant system like a heat pump to keep the heat consistant in the house, while a timber frame which is thermally responsive will work best with a supply on demand system ie rads & oil

2. Poor design of floor layout with regards to orientation and solar gain

3. Users keep turning off systems which are designed to regulate themselves due to the lack of knowledge, and end up opening windows in the morning on houses with MHRV etc

4. Poor installers, I find that a lot of installers out there do not know much about how the system they are installing actually works with other building systems or fabric, this therefore leads back to point one, and the client is then fully reliant on their designer

You will find poor examples of every system, its foolish to judge any one system based on someones opinion without knowing what else is going on in the house regarding the the other systems they have, the building fabric, the orientation of the house, and how they are using the house.

thebackbar

Metric Tensor wrote: »

I'm going to buck the trend a bit here -

On some of the new houses I recommend high efficiency condensing oil fired boilers with rads rather than heat pumps. When I discuss with the client how they propose to live and what they expect from a heating system I often find that their proposed lifestyle is not best suited to a heat pump / uf lifestyle.

It's amazing how little oil is actually used to keep a new house warm, particularly when coupled with appropriate thermal mass and a good MHRV system.

I always require good air-tightness detailing from the contractor and I always recommend MHRV. (Sometimes the clients don't agree regarding MHRV and if so we look at alternatives!)

how do you get over the renewables requirements for part L when you go with a condensing boiler ?

Metric Tensor

thebackbar wrote: »

how do you get over the renewables requirements for part L when you go with a condensing boiler ?

Solar panels and wood stoves usually.

ArraMusha

Metric Tensor wrote: »

Solar panels and wood stoves usually.

Are there specific models of wood burning stoves that need to.be used?

Metric Tensor

ArraMusha wrote: »

Are there specific models of wood burning stoves that need to.be used?

They have to be stoves capable of burning ONLY wood and they must have documentation from the manufacturer saying that they cannot burn any other material.

delfagio

thebackbar wrote:

how do you get over the renewables requirements for part L when you go with a condensing boiler ?

PV Solar Panels, and wood burning stove,

ArraMusha

Update: A condensing oil burner+woodburning stove+ solar will comply with the regulations. This is the type of system I'm considering strongly , possibly with a mechanical HRV(fan +foam+ceramic in wall).
Alu rads will be installed up+down and 2 pipes to add heatpump or other in the future.
Cost of this heating system is approx 6k. Ventilation is approx 500 per unit.

893bet

6k? No chance!

For labour, solar kit, hot water tank, heating controls, all the rads, pipes, fittings, boiler, oil tank, stove etc.

You won't have change from 12k, maybe more depending on size of solar required, number of rads etc.

My heating system is similar. External oil boiler, rads, 50 tube solar with 400l tank(this was 3k or more alone for solar), rads, plus two stoves.

thebackbar

ArraMusha wrote: »

Update: A condensing oil burner+woodburning stove+ solar will comply with the regulations. This is the type of system I'm considering strongly , possibly with a mechanical HRV(fan +foam+ceramic in wall).
Alu rads will be installed up+down and 2 pipes to add heatpump or other in the future.
Cost of this heating system is approx 6k. Ventilation is approx 500 per unit.

what size house do you mind me asking ?

ArraMusha

thebackbar wrote: »

what size house do you mind me asking ?

200sqm

ArraMusha

893bet wrote: »

6k? No chance!

You won't have change from 12k

6k is for material only

893bet

ArraMusha wrote: »

6k is for material only

I still can't see it.

Off top of my head my materials....
Solar materials 3k
Boiler 1200
Solar tank 400l 1k

Plus all pipe work, copper, rads, heating controls, valves, oil tank, etc.

Not sure if you are including cost of stove in your 6k.

I have no change from 17k (might even be more but that is a minimum) when mine is all done (includes cost of 5k for two nice stoves). And my materminal cost is low as I have a close contact in suppliers.