ASHP flat roof installation

[Marvin]

So, ASHP on flat roof. Boiler going.

 

Now, where the hell do I put the heat pump supply rotary isolator?

[Marvin]

Other view...

[dpmiller]

I recognise that ASHP...

 

Just screw the isolator to the side of the unit

 

 

[TonyT]

As above.

or have the isolator internal with appropriate signage, advising of this 

[SteamyTea]

Is that the best place to site the ASHP, is there a solid wall below it?

[Marvin]

9 hours ago, SteamyTea said:

Is that the best place to site the ASHP, is there a solid wall below it?

 Good question. Yes the only place below the flat roof that does have a wall across the span.

I am also not sure about the insulation being crushed, the EPDM being worn by vibration or the vibration entering the building but will react to these if they arise.

[Marvin]

10 hours ago, dpmiller said:

I recognise that ASHP...

Yes, you and conor probably will. 

Have been reading your info. Very interesting. 

 

I came across the pump searching for one small enough for our bungalow. We had already renovated and upgraded the insulation, airtightness and installed MVHR. Because we heated the bungalow and hot water only using bottled gas we also knew our energy usage results, which were worse than theory but better than hoped and this helped us choose the unit.

 

[Marvin]

Coolenergy ASHP up and running from yesterday.

[Marvin]

Runs very quietly. Almost no noise from the unit outside. Fridge/freezer makes more noise inside.

[dpmiller]

Unpossible. Stupid hateful noisy things don't ya know?

[Marvin]

Yes but you try living without a fridge/freezer these days.. 

[jfb]

Do their heat pumps work in reverse for cooling?

[Marvin]

This model is the single phase  Invertech air to water ASHP. I don't know about the other models. We're running it using radiators and a coil in the MVHR system

 

Yes programmable cooling.

 

[jfb]

1 hour ago, Marvin said:

We're running it using radiators and a coil in the MVHR system

 

What is the coil in the MVHR?

Does that do both cooling and heating via the MVHR? And presumably require extra pipework to the MVHR?

[Marvin]

Inside coil box

[Marvin]

Coil Box

[Marvin]

filter box

[Marvin]

Only just got the ASHP running.

 

Purchased and will be adding one of these coils:

Duct water heater.pdf

 

Had to add an air filter as the water coil will be positioned just before the entrance to the MVHR box on the inlet pipe. This should allow condensation to flow out of MVHR box through the drain point.

 

Yes pipework to MVHR.

Yes warm and cool as set on ASHP.

 

Advised to have separate port valves to both radiators and coil.  If the coil works ok, then when cooling, I can turn the temperature down lower than I would for radiators, and just run the coil and this would avoid the  risk of condensation on the radiators because I should be able to leave them off. (enough cooling from coil hopefully)

 

That's the cunning plan!  We shall see.

 

 

 

[A_L]

53 minutes ago, Marvin said:

Had to add an air filter as the water coil will be positioned just before the entrance to the MVHR box on the inlet pipe.

 

I may misunderstand your layout, but if the coil is between the outside and the MVHR heat exchanger how will you, unless you have a summer bypass, prevent the outgoing air heating the cooled incoming air?

Similarly if the coil heats incoming air the the outgoing air will cool it in the heat exchanger.

Is the condensate drain not only on the outgoing side of the heat exchanger?

[joth]

13 hours ago, Marvin said:

 

Advised to have separate port valves to both radiators and coil.  If the coil works ok, then when cooling, I can turn the temperature down lower than I would for radiators, and just run the coil and this would avoid the  risk of condensation on the radiators because I should be able to leave them off. (enough cooling from coil hopefully)

 

That's the cunning plan!  We shall see.

 

Have you insulated all the supply side MVHR ductwork into each room? If not, you'll need to keep the temperature on the coil not so cold anyway, to avoid condensation forming in/on the ducts. 

 

 

 

Edited June 25, 2021 by joth

[Marvin]

3 hours ago, joth said:

Have you insulated all the supply side MVHR ductwork into each room? If not, you'll need to keep the temperature on the coil not so cold anyway, to avoid condensation forming in/on the ducts. 

 

 

 

Good question.

 

ALL 4 lines of ducting insulated everywhere within the building/ loft.

[Marvin]

16 hours ago, A_L said:

 

I may misunderstand your layout, but if the coil is between the outside and the MVHR heat exchanger how will you, unless you have a summer bypass, prevent the outgoing air heating the cooled incoming air?

Good question. Yes we have a summer bypass.

[Marvin]

16 hours ago, A_L said:

Similarly if the coil heats incoming air the the outgoing air will cool it in the heat exchanger.

Is the condensate drain not only on the outgoing side of the heat exchanger?

I don't know. I will contact the manufacturer and see if I can add a drain on the other side.... 

[Marvin]

3 hours ago, Marvin said:

I don't know. I will contact the manufacturer and see if I can add a drain on the other side.... 

Manufacturer technical department states the existing condensate drain will remove condensation produced when either the inlet air is colder than the exhaust air, or when the exhaust air is colder than the inlet air. so all good from that point of view.

[hallga]

On 24/06/2021 at 14:12, jfb said:

Do their heat pumps work in reverse for cooling?

some can reverse for summer

 

On 24/06/2021 at 14:12, jfb said:

Do their heat pumps work in reverse for cooling?