Ecocent ESP 200L

[wildwest]

'Afternoon all, I am trying to get some unbiased views on my plans.

We are about to convert and extend an old outbuilding, and my plan is to use an Ecocent Heat Pump (200l) for hot water and heating.

As you'll see from my linked plan, it's a small area – around 40m2, and aimed for two people as a holiday let. There's one shower room, and two sinks, plus UFH for two zones – bedroom/shower and kitchen/living.

I'd like an opinion on the layout of the Ecocent setup (it'll be placed within a (hopefully) soundproof enclosure, but accessible through removeable panels. It will then take air from the shower room and above the kitchen worktops.

There will also be a wood burning stove in the living room.

Thanks

[Bodidly]

Welcome Wildwest

I am afraid I don't know anything about the Ecocent but it would probably be worth reading this thread. http://www.navitron.org.uk/forum/index.php/topic,13332.0.html

Beau

[martin]

I think that at the very least I'd incorporate solar hot water into the scheme, so that during the warmer months of the year you're not wasting high grade energy for heating.........
Unless your insulation levels are very high, any ASHP is going to be pricey to run.......

[dhaslam]

That type of heat pump  only works properly where there is another  source of heat.   In a holiday let that might not always be the case  so there might be hot water and a very cold appartment.   Since it is probably going to be used more in summer a small solar setup with immersion backup would probably be better with electric underfloor electric heating on night rate electricity.

[wildwest]

Just to add, the building will be very well insulated, and the bottom left corners of the plan are south-west facing, in Aberystwyth, west Wales.

My other options up there are oil/electric/lpg.

Another option would be to use electric heating for hot water ... one electric shower, one electric water heater for the sinks?

[StationHouse]

Going by my experience just about anything other than an ASHP will be more expensive to run. Suggest looking into Mitubishi Ecodans...

[qeipl]

Sean,

DHW:

A 200 litre Ecocent will be ideal for 2 people.
Capital costs will be much less than solar thermal, lpg, or oil.
Running costs will be more than solar thermal on sunny days, less than an immersion heater on cloudy days.
Running costs in cold weather will be mitigated by feeding the ASHP warm air (as shown in the plan) - a continuous COP of c.3 is realistic which competes well with lpg/oil/solid fuel.
If there is a gap between lettings the Ecocent will have to be switched on a few hours in advance of visitors arriving.


UFH:

Assuming good u-values all round (walls/roof/floor <0.18; windows <1.5) and well-sealed construction..
For more than half the year the sun will heat the building directly.
For some of the colder months the Ecocent will recycle energy from the sun, showers, washing, cooking, bodies, etc. via the UFH, which will keep the house fresh, dry and warm.
For the coldest, darkest part of the year you will need some additional source of heat. I use a solid fuel boiler/radiators. Others use a wood-burning room heater. If the house is a holiday let and rarely used in winter the most cost effective additional heat source will be electric (panel heaters or an electric UFH boiler). Does your drawing show a wood burning room heater in the living room?

In terms of capital cost:carbon emissions ratio the Ecocent is probably more effective than any of the alternatives.
Ditto capital costs:running costs.
If 'greenness' is more important than capital costs then add solar thermal to the Ecocent set-up.


Proposed set-up:

Fresh air ducts from outside must be provided for the ASHP - total csa must be greater than the csa of the heat pump ducting.
Low level fresh air ducts are best (mine come in under the floor). I'd suggest one into the kitchen and one into the bedroom.
A high level air path from the bedroom to the shower room is required.
The ASHP intake from the shower room must be fitted with an automatic shutter that's controlled by a humidistat and an occupancy switch, so that it's only open when required (other wise you'll struggle to keep the shower room warm).

The main ASHP intake over the kitchen counter is not recommended as it's too close to the cooker (grease in the HP is not good). I know there's an extractor hood but no guarantee that people will use it.
The main (always open) ASHP intake would be better in the ceiling (apex, if possible) of the living room.
If there is a wood burner in the living room it must have a dedicated air supply from outside that's connected directly to the stove (otherwise the stove will fight with the ASHP).

Having a separate UFH circuit for the shower room is recommended (nice to have the option of a warm shower room and cooler bedroom).
Adding a heated towel rail circuit for the shower room is recommended (floor area is small for UFH and warm towels are nice to have).

Hope that helps.

Malcolm

[sam123]

Like anyother exhaust air heat pump, this ecocent is also a big paradox. It suck 450m3 air in hour...takes energy from it and blows it to outside.

That 450m3 means 125 liter/second constant flow from house.

Lets say that outside has temperature -10 and inside is +20. This ecocent (what a joke) sucks 125l/s 20 degree air from the house and same time there comes 125 l/s -10 degree air in to house.

Ecocent have to keep air blown to outside  temperature above zero, otherwise it frozen.

Lets calculate:

+20---> +3 125l/s = 2570 wats taken from air with 800w compressor --> COP  3,21
(this brochure text for innocent buyer)

BUT

Meanwhile there is incoming -10 degree air with same 125 l/s flow...

You have to warm it to +20, otherwise your house get colder 

We have to warm incoming air 30 degree (from -10 to +20) and It takes 4526W

WTF?

That means by using 800W compressor in -10 degree outside temperature we get 1956W extra consumption. Sounds like a bargain 

Okay. If it is warmer we get benefit.

Let's calculate: Outside temperature + 10 degree and inside + 20 degree.

We get 2570 W and we need only 1512 W to warm =  1058 W benefit with 800W compressor => COP 1,32

Final conclusion is: If you live in Africa it work nicely!

Great piece of machine if you use it summertime, but using it 40m2 house is pure madness.

cheers, Sami

P.S There is a lot of similar pumps in ebay.de starting from 1400 euros

[billi]

P.S There is a lot of similar pumps in ebay.de starting from 1400 euros

True  similar machine delivered to Ireland  to my  door from Germany  1600 Euro

But stainless  tank and solar coil inside ...........

I guess they all get these units  from China and place a lable on them  ,  and try to advertise aggressively

Someone told me the other day ,that some heatpump compressors  are not designed for continuous running .........any idea, if thats true



But nothing wrong  with a heatpump and PV on the roof in my opinion 

Billi

[qeipl]

Like anyother exhaust air heat pump, this ecocent is also a big paradox. It suck 450m3 air in hour...takes energy from it and blows it to outside.

That 450m3 means 125 liter/second constant flow from house.

Lets say that outside has temperature -10 and inside is +20. This ecocent (what a joke) sucks 125l/s 20 degree air from the house and same time there comes 125 l/s -10 degree air in to house.

Ecocent have to keep air blown to outside  temperature above zero, otherwise it frozen.

etc....

Sam123,

You're absolutely correct that energy has to be added to the fresh air that comes into the house.

But you seem to be assuming that all of that additional energy has to be supplied by consuming some sort of fuel.

You're forgetting that the sun supplies all of this energy for most of the year.

My house uses approximately 4700kWh of electricity per year.
Solid fuel (coal + wood) delivers c.1600kWh/year of warm air to the house.
So the total energy consumption of the house is 6300kWh/year.

Floor area = 100m^2, so energy consumption = 63kWh/m^2/year.

PassivHaus standards limit primary energy use to 120kWh/m^2/year.

Despite not being built to PH standards my house easily performs within the limits because it combines solar gain with an ASHP.

Sean's house is only 40m^2
Assuming his heat loss rate is the same as mine, his average space heating consumption should be around 35.4 x 40 = 1416kWh/year.


Malcolm

[martin]

"You're forgetting that the sun supplies all of this energy for most of the year"

[billi]

Malcom

I though the heating consumption in "Passive Houses" is smaller than  15 Kw/m²/per year.

[A.L.]

My house uses approximately 4700kWh of electricity per year.
Solid fuel (coal + wood) delivers c.1600kWh/year of warm air to the house.
So the total energy consumption of the house is 6300kWh/year.

Floor area = 100m^2, so energy consumption = 63kWh/m^2/year.

PassivHaus standards limit primary energy use to 120kWh/m^2/year.

Despite not being built to PH standards my house easily performs within the limits because it combines solar gain with an ASHP.

The PH standard suggests that 2.7kWh of primary energy are required to produce one kWh of electrcity, 1.1kWh/kWh for coal and 0.2kWh/kWh for wood. On this basis and assuming a 50/50 coal/wood split you use

4700*2.7 = 12690kWh
800*1.1 = 880kWh
800*0.2 = 160kWh

or 13730kWh or 137.3kWh/m² of primary energy thus exceeding the PH standard

[qeipl]

My house uses approximately 4700kWh of electricity per year.
Solid fuel (coal + wood) delivers c.1600kWh/year of warm air to the house.
So the total energy consumption of the house is 6300kWh/year.

Floor area = 100m^2, so energy consumption = 63kWh/m^2/year.

PassivHaus standards limit primary energy use to 120kWh/m^2/year.

Despite not being built to PH standards my house easily performs within the limits because it combines solar gain with an ASHP.

The PH standard suggests that 2.7kWh of primary energy are required to produce one kWh of electrcity, 1.1kWh/kWh for coal and 0.2kWh/kWh for wood. On this basis and assuming a 50/50 coal/wood split you use

4700*2.7 = 12690kWh
800*1.1 = 880kWh
800*0.2 = 160kWh

or 13730kWh or 137.3kWh/m² of primary energy thus exceeding the PH standard

Thanks A.L.

I thought I'd got that wrong after I'd posted it but was sure someone would correct me.

However, 137.3kWh/m^2/year isn't too bad for a house that was built without any knowledege of PH standards.
The point is that the ASHP DHW UFH combination doesn't result in huge energy bills.

[sam123]

Sam123,

You're absolutely correct that energy has to be added to the fresh air that comes into the house.

But you seem to be assuming that all of that additional energy has to be supplied by consuming some sort of fuel.

You're forgetting that the sun supplies all of this energy for most of the year.

Thats why I said that this exhaust air pump works great in Africa. You get hot air from outside and store it to DHW and blow cold air to room for cooling.

That 125l/s air volume is crazy for normal house. I would keep airflow in decent level with MHRV...why using 800W compressor for heat recovery, when you can use rotating heat exchanger spinning with 3 watts  

Heating and ventilation are always married together. You get much better year efficiency with good MHRV + ASHP (air to air) + electric boiler for DHW. (That is only if you keep your house +22 degree inside and normally ventilated, some people seems to keep rooms at +13-15 degree)

We have here 276m2 in two floors, GSHP + 210m bore hole + MHRV. Last year less than 13500 kWh (all electricity).

I keep +22 inside the house even it is a little bit cold outside