Integrating an MVHR to our build

[Gone West]

2 minutes ago, joe90 said:

for that reason I used a recirculating hood with charcoal filters and the extract 2 mtrs away. Works well

Same here .

[djcdan]

23 minutes ago, PeterStarck said:

The only problem with that approach is that if in the future a lot of frying of food takes place the oil droplets will condense on the inside of the ductwork. Not an easy job to clean.

Yes, we'll probably be looking at the recirculating cooker hood approach to remove grease particles.

 

14 minutes ago, joe90 said:

I used a recirculating hood with charcoal filters and the extract 2 mtrs away. Works well

Good to know. I'll bare this in mind when looking for a hood.

 

14 minutes ago, joe90 said:

18 hours ago, djcdan said:

she'll be freezing in bed at 12C on winter nights ?.

Aint going to happen

That's what I've told her. Not been easy to convince but I think she has just about accepted that rads aren't needed in the bedrooms!! Upstairs, we have a cupboard designated as a 'drying' room for drying clothes in the winter months. The door will likely be closed whilst washing is drying but there will be an extract point for the MVHR in that room. With the door being closed - therefore not allowing at much heat to enter that room from downstairs - is it recommended to place a rad in there too as well as the two ensuites?

[joe90]

2 minutes ago, djcdan said:

Upstairs, we have a cupboard designated as a 'drying' room for drying clothes in the winter months. The door will likely be closed whilst washing is drying but there will be an extract point for the MVHR in that room. With the door being closed - therefore not allowing at much heat to enter that room from downstairs - is it recommended to place a rad in there too as well as the two ensuites?

personally I do not like drying clothes indoors, I have seen so much damage done by this being done (mould, sagging ceilings) . However some here dry clothes in a room with an extract to the MVHR and they say it works well!

[PeterW]

18 minutes ago, djcdan said:

With the door being closed - therefore not allowing at much heat to enter that room from downstairs - is it recommended to place a rad in there too as well as the two ensuites?

Can you not use the room to house something like the hot water cylinder ..? That will create enough warmth. MVHR needs an undercut of 10mm on the doors so you will get air flow. 
 

Are you installing towel rads in the en-suites..? Electric or water ..? 

[djcdan]

16 minutes ago, joe90 said:

personally I do not like drying clothes indoors, I have seen so much damage done by this being done (mould, sagging ceilings) . However some here dry clothes in a room with an extract to the MVHR and they say it works well!

Yes, I'd seen others mentioning it to be fine with an MVHR extract point. With this constantly extracting - even when washing is not in that room - it should remove any moisture particles to keep it damp-free.

 

4 minutes ago, PeterW said:

Can you not use the room to house something like the hot water cylinder ..? That will create enough warmth. MVHR needs an undercut of 10mm on the doors so you will get air flow. 

The room isn't that large. It is 2.06 * 0.88m on the top floor of a 1.5 story. So 0.92m of the 2.06m length of the room is full height. It is probably just about large enough for clothes drying and nothing much else.

 

6 minutes ago, PeterW said:

Are you installing towel rads in the en-suites..? Electric or water ..? 

Not sure. It was going to be water, but seeing as though we're not installing rads to bedrooms, it seems logical to consider both.

 

Advantages of water - cheaper to run?

Advantages of electric - negates having to plumb any heating upstairs so cheaper to install.

[joe90]

3 minutes ago, djcdan said:

Advantages of water - cheaper to run?

Advantages of electric - negates having to plumb any heating upstairs so cheaper to install.

I went electric with low wattage elements, timer . Easy peesy 

[djcdan]

1 minute ago, joe90 said:

I went electric with low wattage elements, timer . Easy peesy 

Are you able to achieve higher rad temps compared to water coming from an ASHP?

 

It certainly does seem to be the easier option here. Any advantages of running water to these rads? 

[joe90]

3 minutes ago, djcdan said:

Are you able to achieve higher rad temps compared to water coming from an ASHP?

Yes, in fact I had to change the elements to lower wattage as someone scalded themselves in the guest bathroom ? My ASHP heats water to 48’ only (which is hotter than it sounds when doing the washing up!).

 

5 minutes ago, djcdan said:

Any advantages of running water to these rads? 

Yes, the COP of the ASHP but as we had no UFH upstairs the work/grief was not worth it for the short time they are on and only in winter (IMO).

[djcdan]

7 minutes ago, joe90 said:

14 minutes ago, djcdan said:

Any advantages of running water to these rads? 

Yes, the COP of the ASHP but as we had no UFH upstairs the work/grief was not worth it for the short time they are on and only in winter (IMO).

Ok, so overall the cheapest way to run these rads is to use water, and taking advantage of the COP offered by the ASHP.  However low wattage options are available. What are the wattage of your elements?

But the better temps and simplest route for installation is electric. This cuts out the need to take any heating solutions from the ASHP upstairs saving on the plumbers time needed for the job.

[joe90]

13 minutes ago, djcdan said:

What are the wattage of your elements?

If I remember correctly 70w, you can get thermostat controlled ones as well . 

 

 

[Bitpipe]

We have an extract in the utility and this is where our washing machine and condensing tumble dryer are. We mostly use a drying rack (has an optional heating option if you want to speed it along) and the airflow means the clothes dry quickly.  

[djcdan]

11 minutes ago, joe90 said:

If I remember correctly 70w, you can get thermostat controlled ones as well . 

 

70w is pretty decent. Around 1p an hour.

 

10 minutes ago, Bitpipe said:

We have an extract in the utility and this is where our washing machine and condensing tumble dryer are. We mostly use a drying rack (has an optional heating option if you want to speed it along) and the airflow means the clothes dry quickly.  

She has a thing against tumble driers... Damage to clothes and unnecessary power consumption. But throw a new born in to the mix with the increased washing load, and I can see that opinion quickly changing!!

[Mr Punter]

2 hours ago, PeterStarck said:

The only problem with that approach is that if in the future a lot of frying of food takes place the oil droplets will condense on the inside of the ductwork. Not an easy job to clean.

 

For that reason I have a hood with a bfo remote external fan with 150mm ducting.  Good for stir fries.

[Gone West]

1 hour ago, djcdan said:

Yes, I'd seen others mentioning it to be fine with an MVHR extract point. With this constantly extracting - even when washing is not in that room - it should remove any moisture particles to keep it damp-free.

We dry our washing in the wet room which has an electric towel rail and a MVHR extract vent. It dries overnight.

[Temp]

3 hours ago, djcdan said:

The door will likely be closed whilst washing is drying but there will be an extract point for the MVHR in that room.

Needs a vent in the door or at least a gap under it or the extract won't work.

[djcdan]

15 minutes ago, Temp said:

Needs a vent in the door or at least a gap under it or the extract won't work.

We'll have a 10mm gap beneath the door.

[SteamyTea]

3 hours ago, joe90 said:

If I remember correctly 70w

So an old lightbulb's worth.

Seem to remember a heated debate over at the other place about low energy lighting taking away the heating element.

[DavidO]

5 hours ago, PeterStarck said:

The only problem with that approach is that if in the future a lot of frying of food takes place the oil droplets will condense on the inside of the ductwork. Not an easy job to clean.

 
My wife is a nutritionist, so only modest frying permitted here....!

Having said that we redecorated during the summer which involved removal of the vent cowls, which I inspected and cleaned to arms length. There was a bit of dust but no oil/grease to get excited about given that was the first time I’d had a serious look at them for 7 years. Also the vents are approx 2.5m distant from the hob which probably helps.

[Gone West]

7 minutes ago, DavidO said:

My wife is a nutritionist, so only modest frying permitted here....!

Yes, good idea, we don't fry food either. It's if we sold up and the new owners didn't behave in the same way that there would be a problem. If the MVHR is extracting correctly then the oil droplets would condense in the ducting if not they would condense on kitchen surfaces.

[joe90]

35 minutes ago, SteamyTea said:

So an old lightbulb's worth.

Seem to remember a heated debate over at the other place about low energy lighting taking away the heating element.

I remember the GBF where Tony heated his UFH with one of these elements and had to put an “old” bulb in the guest bedroom to heat it for a family member (if I remember correctly ?).

[Bitpipe]

4 hours ago, djcdan said:

70w is pretty decent. Around 1p an hour.

 

She has a thing against tumble driers... Damage to clothes and unnecessary power consumption. But throw a new born in to the mix with the increased washing load, and I can see that opinion quickly changing!!

 

PV on roof and only use when sun is shining, that answers the energy issue.

 

If you're using ASHP then you should already be considering PV  - even without FIT (upside is that panels and installation costs are now lower), you will still generate meaningful energy and in summer you will have free cooling of your slab.

 

A decent (e.g. Miele) condenser dryer will not destroy your clothes but if you have a decent drying space an a MVHR extract nearby then you will rarely use it. Ours is almost exclusively for towels and duvets & covers etc - anything that won't fit on the dryer or we want fluffy.

 

 

[djcdan]

4 minutes ago, Bitpipe said:

PV on roof and only use when sun is shining, that answers the energy issue.

 

If you're using ASHP then you should already be considering PV  - even without FIT (upside is that panels and installation costs are now lower), you will still generate meaningful energy and in summer you will have free cooling of your slab.

I looked in to PV and honestly, can't see the hype in current circumstances.

 

We'd have enough space for a 4KW system spread over a southern facing roof on the house and the southern facing face of the garage roof. It would take 10 years to pay back and without a battery unit (which is unaffordable on current budgets), a portion of the electricity generated will be lost. We aren't able to fit a smart meter in our location at the moment, which I believe was a prerequisite to have electricity fed back to the network.

 

PV and battery technology will be unrecognisable in 4-5 years compared to what we see today and will gain significant awareness as the government chase their green targets. My plan is to have this retrofitted when the technology has matured with grants and offers similar to FIT return. Ideally, we would just utilise the roof space on the garage (since this is out of sight of the property), and fit the battery units in the garage where the meter position is.

 

In practice, our build has a lot going for a PV installation; we have uninterrupted southern facing roofing and have a three phase supply fitted to allow us to optimise overgeneration to be fed back to the network. But on tight build budgets, for technology that will inevitably improve in a few short years, can be retrofitted and currently has no 'perks', I don't see this as the time to install. In 5 years, we'll likely be in a position to own an electric car, we'll have better batteries installed and would be able to fit a 16+KW system where I currently am able to fit 4KW to allow the system to be a little more self-efficient and cost effective than it currently is.

[Bitpipe]

Fair enough but in your payback model factor in (if you have not already) that if you use in roof trays for PV you save the cost of covering that part with tile/slate.

 

Also VAT free if you do it now vs later.

[SteamyTea]

PV now costs less than single glazed windows and frames.  There has to be a point where it cannot get any cheaper as the materials will not get any cheaper.

 

As @Bitpipe says, it can be cheaper than a roof covering, fit them and connect them up later if it is a cashflow issue.

 

Does anyone do a payback calculation between different tiles?

[Bitpipe]

3 hours ago, djcdan said:

We'll have a 10mm gap beneath the door.

 

To be pedantic you need 7600mm2 so 10mm for standard width door but obv less if your door is wider