MCZ Musa Hydro 15kw - thoughts

[Deleted User]

I can see exactly where you are coming from Tina.

We have had our musa hydro for 3 years and love it, it isn`t noisy and has over 60 different programmes as well as an eco setting or plain on and off. We have it serviced every year and it runs sweetly. We use 10kg bags, which I can manage and we store a tonne, which lasts us a year at least. The house is eco and extremely well insulated so only uses one bag in 2 days at £260 a tonne

Ours is 15kw and is more than enough for our 4 bed detached house, we don`t use it except in winter as we don`t need to. I don`t think it is at all suitable for Tina`s situation or for a poorly insulated house but for us, it is marvellous

We keep the pellets in the garage and insert the bag upside down into the hopper, there is minimum dust, if any

thehat

We too have a Musa Hydro 15kW - in a 3-bed detached bungalow, moderately well insulated; have had it for 3 years. Great things:
- contrary to what Chardeka says, you can have a setup that means the Musa can be programmed to come on whenever you want - but you may need a thermal store, as we have, and it took the installers a good deal of head-scratching to start with (and the Italian UK rep came to our house to help translate in conversations with engineers in Italy!)
- it works a treat, making masses of hot water quickly and plenty of heat

Not so good:
- it is noisy - ours is in the lounge and it's hard to hear the telly when the stove fan cycles on every 20 minutes
- we also had problems with noise resonating in the flue, though this was mostly solved by buying a special (expensive) flue silencer
- installers are few and far between - ours in about 40 miles away, and expensive for call-outs (not needed other than an occasional checkup - but that said today it looks like the stove pump may have failed!)

Other points:
- the pellets are expensive, but you can get them cheaper than suggested above - a tonne (96 x 10kg bags) can be bought for £250, or even less in summer when there are discounts; also those Countrywide Farmer stores sell individual bags for £2.75 - I often just get a car load when we need them.

Gareth83

I have been looking into a MCZ Hydro 15kw for my 4 bed Victorian terrace which has benefitted from external and internal wall insulation.

The house originally scored an EPC rating of 1 out of 100 as it had single glazed, no loft insulation, coal back boiler, no rads and solid wall construction. Now all the above has been upgraded and there is no gas heating system I am looking into biomass.

I have a few questions.....

1. Can I install the system myself to building regs and get a MCS registered company just to commission it? If so, how much should I be charged? For a gas combi my local gas safe engineer will connect and commission for £200 so long as I do the plumbing.

A local MCS company reckons they have to do it all and have quoted an extortionate £13,000! Even though I have the thermal store and will do th wet side of it.

2. If I qualify for the £2000 grant do I then get the 12.2p per kw? I understand they take the £2000 off so you are not double paid? If this is so I'm not sure I can justify the install. Gas is cheaper per kw/h. To make the £2000 back that is a lot of time.

Any decent calculators to work all this out? I do not trust companies that sell this technology as the figures will always be manipulated.

Pellets are £250 per tonne so approx. 5p per kw/h, gas is ~6p per kw/h. Is there really a benefit seeing as I can install a gas boiler far cheaper....

3. If the flue is 80mm does it 'HAVE TO' be double skinned or is this just best practice? Can it terminate below roof level like a gas flue or must it go above roof level? If I can run it in 80mm stainless single skin I can go straight up my single storey roof and be done for ~£100

Thanks in advance

Gareth83

Actually that can't be right as you can get a backdated install certified. So how much should I expect to pay to get the install certified and what exact questions/things will they check?

Thanks

Robwiz

@Gareth83 – it's not quite as straight forward as that!

First, your RHI is calculated on your deemed heat demand from your Energy Performance Certificate (EPC). As you scored 1, that should be a big number. Take your deemed demand and multiply it by 12.2p per kW for your annual RHI payment figure. Now divide that number by 4 to get your quarterly payment figure. The £2000 RHPP repayment will be deducted equally over the 7 years of RHI – so £71.42 per quarter.

The people who will do best out of RHI are those with very energy inefficient homes – typically farmhouses where they replaced LPG or oil. Those installs also benefited from the higher boiler efficiency of the new biomass boiler.

I would only self-install a biomass boiler if I was confident that I could maintain it without support. You need to choose a manufacturer and installer who are going to be around for the expected 20 year life of your new boiler.

When I was getting quotes, I became frustrated with how installers would recommend and price up the most expensive option they could which just about gave a payback over the 7 years of the RHI. That's not good enough – the Government intention is to give 20 years worth of subsidy over the 7 years' payments.

The renewable heating market is like the wild west, with plenty of chancers looking to make a fast buck. It's interesting that some suppliers have stayed out of the MCS system as in their view it inflates prices – look up Jaaspi for example.

That said, Gas Safe is also a cartel with inflated labour costs and there are plenty of gas fitters who will take short cuts installing a new system which could make living with it an expensive hell for years.

Simplicity is your friend. I suggest you research more – air to air heat pumps can be a cheaper heat source than gas. Read more in this blog.

Pellets can be risky – they turn to sawdust if they get damp and some boilers can get clogged up easily. Log burning boilers are usually a lot cheaper and there's a lot less to go wrong. You can run them on briquettes which work out about the same price as pellets if you buy from Verdo and you get guaranteed moisture content and heat output.

Also, masonry heaters are simple, resilient heat sources – take a look at this one for example. I have no connection with any of the manufacturers I have named.

Gareth83

Thanks for your response, however I am no confused even more....

Air to air sounds good but.... as they run on electric electric is likely to increase in cost is it not? They cannot heat DHW so I'm not sure I'd want to run a stove back boiler each day just to have showers and hot water...

How do you circulate the air efficiently around the house? At least with radiators and TRV's the rooms can be heated evenly.

Based on the most recent EPC which includes the fact there is no insulation or central heating it calculates the energy requirement as:

Space Heating 22,685
Water 5237
Total = 27,922

In order for me to qualify for the grant I would need loft insulation as a minimum so it calculates it as a -5,548 if this was done...

So my energy requirement would be 22,374kw at 12.2p per year I would get £2729 RHI payment - 4x £71.42 = £2443.32

However as I have also qualified for a grant for internal/external wall insulation the EPC amends this to 22,374 - 5700 = 16,674

So I guess they would base it on that figure so would get 16,674 x 12.2p = £2034 RHI - 4 x £71.42 = £1748.32

However, this is based on my EPC values.... I understand that an actual energy meter needs to be installed and the payment is based on this? Can yo confirm? If I only used 3 tonnes of biomass a year @ £230 I would be around £1000 better off each year which sounds good to me....... Until I get the true install cost which is going to be extortionate.

Can I just not install it and get a MCS company to sign it off? If so, how much to pay?

I could possibly use a wood back boiler but again is there a grant available and can I install myself? Pellet boilers are a lot more efficient compared to log burners are they not?

[Deleted User]

you are counting your chickens re RHI Gareth, I doubt it will happen after the cost of pv to the country. I still love the mcz hydro 15 almost 4 years of use, it is on now and running almost quietly, just a buzz at intervals as the auger works and then more of a roar as the exhaust fan works but we don`t find the noise intrusive at all

If it were very cold outside and a grey day then running it from 6 am to 12 midday gives us more than enough heat to keep us warm until next morning. Today the sun will shine and the house will have solar gain so the stove will be on approx from 6 to 10

Getting older now, we have the potential problem of constantly getting bags of pellets in, ok at 10kg for several years at the moment but not every countrywide store has them, this involves moving and storing a tonne, not a good thought for later years. If we had a gas supply then I would definitely have gas ch and hot water with a small stove/fire for visual effects. Everyone loves the looks of the mcz though

We do get it serviced every year and am keeping hold of the installing engineer, who is good, so it runs sweetly. Our eco house is almost code 6 and highly efficient with a heat store floor and wall (behind the stove) we have wool insulation between floors, solar gain etc

I would not like to be running this type of pellet stove in a less energy efficient home, I would be forever moving pellets

[Deleted User]

thehat wrote: »

- it is noisy - ours is in the lounge and it's hard to hear the telly when the stove fan cycles on every 20 minutes
.

I have to agree with that, I would not like the tv to be in the lounge with our stove. Our tv is in a snug

Robwiz

The RHI payments would be based on your deemed heat demand from your EPC. My understanding is that heat meters are required in commercial installations and where the biomass boiler isn't the only heat source (e.g. you keep a gas or oil boiler installed).

It makes sense to insulate as much as you can first anyway as it will reduce the size (and capital cost) of the boiler you install as well as reducing your fuel consumption.

Wood burning stoves with backboilers don't qualify for RHI.

For water heating, I'd suggest you look at whole life costs. Keeping 160-220 litres at 60º in a cylinder every day is very costly. So is the cost of a cylinder and all the plumbing. A 9kW electric shower will use very little energy for a 5 minute shower – 750W at a cost of 9p (assuming electricity at 12p/unit).

Similarly, point of use electric water heaters on basins and sinks will heat only the hot water required, although with cold fill dishwashers and washing machines, how often would the kitchen hot tap be needed?

An air to air heat pump (AAHP), with a CoP of 5 costs 2.4p per hour of heat compared to 4p for gas (based on our 12p/kWh electricity tariff). Gas prices have risen more than electricity so, if anything, the case for the AAHP is likely to improve.

Current UK energy policy is based on encouraging a switch to electricity consumption, the increase coming from renewable sources. My personal view is that's a sensible precaution to be able to heat the home with two different sources in case of disruption. For us, a woodburning stove is an ideal backup to our central heating which goes off in a power cut.

Temperatures equalise - both inside your heat envelope and across the boundaries. So a heat pump working in your largest living space will heat the rest of the house, particularly with doors open. It would modulate its output to maintain the set temperature. Read the Carbon Commentary blog I linked earlier for further information.

As Kittie says, I wouldn't count my RHI chickens. I'm very sceptical of government subsidies as they distort markets and incentivise people to tell confusing, misleading stories with the intention of parting the gullible from their money. You have to do your own research, think for yourself and assess the whole life costs.

For example, nobody challenges the assumption that gas is the cheapest way to heat a house, based on unit prices. On that basis everyone would be driving battery electric cars (lowest energy cost per mile), but they're not. The reason being the higher capital cost and uncertainty over the reliability of the technology. Yet there is overwhelming evidence here and across the net that gas central heating is unreliable and expensive to maintain when it goes wrong.

To illustrate, my central heating broke down on Friday. So we have heated the house with a 8kW rated woodburning stove in the lounge. The kitchen/diner next door is 7m x 4m and was a little cool. A 500W electric panel heater and leaving the lounge door open were sufficient to raise the temperature from 15º to a comfortable 18º with the heater running for 12 hours. That suggests the heat loss from the kitchen is less than 500W.

I used 88kWh of briquettes plus 6kWh of electricity to keep the house acceptably warm – my usual gas central heating consumption is around 140kWh. How do I account for the difference? Boiler losses (it's a 90s boiler with 79% efficiency) and not heating rooms which aren't being used (like bedrooms during the day). We ran the woodburner for 16 hours, so looking at the quantity of fuel burnt, it ran at around 70% capacity.

Gareth83

I understand about insulating prior, if I had to pay for it myself I certainly wouldn't put external insulation in due to the initial outlay, I'm very fortunate to get the insulation for free.

When you say you doubt it will happen regarding RHI it is there already, I know of a few commercial people already receiving it? Energy Saving Trust are involved also

As the property literally has no central heating whatsoever but does have a gas supply I am in a good position to go with whatever.

I have an 8kw Dovre wood burner which I will be installing in the front room for visual effect and room heating.

Basically I have a blank canvas so can go with whatever..... I need to make a decision within 2 weeks.

Air to air sounds good but as it a big four bed terrace I am concerned about the circulation, could I install a whole house heat recovery ventilation system perhaps?

Radiators are good as they are reliable and give an even heat....

I do like my wood burner mind, so even if I got one with a back boiler to run just the hot water it would be fine, I'm sure it wouldn't use that much fuel to heat up water but based on efficiency am I better off just getting gas with a 90%+ efficiency boiler?

I can't seem to find any unbiased reviews of different methods....

I know I do want a power shower mind....