Cooling

[stubiff]

For those with, instructions of, or experience of, MVHR with some form of cooling (and extra heating for that matter), am wanting to understand the scenarios where it has benefits.

I appreciate it is not really a replacement for AC or similar (as mentioned elsewhere).

 

What is the temperature the cooling part outputs at, is this controllable.

How is it controlled, e.g. set a temp that it kicks in at. What range can this be in.

Can it reduce the temp by 2/3/4/X degrees. E.g. could it reduce from 25 to 23/22. Assume it would struggle to reduce once above Y degrees.

Appreciate different models may do different things.

 

I.e. if some overheating can be reduced by other methods, say fabric/external, then the cooling could have the correct comfort effect?

 

Thanks.

 

 

[SteamyTea]

It is the same as calculating heating loss from ventilation.

Mass of air [kg] per time period [h] time specific heat capacity of air [kJ.kg^-1.K^-1] times temperature difference [K]

 

[jack]

20 minutes ago, stubiff said:

What is the temperature the cooling part outputs at, is this controllable.

 

It depends how you implement it, but generally yes. Assuming you're cooling using an ASHP, the main control input would be the supply temperature. You'd then use a thermostat to decide when the cooling turned on and off.

 

22 minutes ago, stubiff said:

How is it controlled, e.g. set a temp that it kicks in at. What range can this be in.

 

Whatever temperature you want. It's generally just going to be a thermostat.

 

23 minutes ago, stubiff said:

Can it reduce the temp by 2/3/4/X degrees. E.g. could it reduce from 25 to 23/22. Assume it would struggle to reduce once above Y degrees.

 

Just about impossible to predict without a lot more information. What sort of insulation does the house have, what's the capacity of the MVHR cooling coil, what's the cooling capacity of the ASHP, etc.

 

My feeling - and it's just a feeling - is that in a well-insulated house and airtight house, with good control of solar gain (e.g., external shutters or blinds), you could expect a decent amount of cooling for a typical cooling arrangement, as long as you keep it running fairly continuously. The low rate of air delivery with MVHR means you aren't going to come home to a hot house in the middle of the day, turn the cooling on, and have the house be noticeably cooler in half an hour. If you want that, you're far better getting some sort of air conditioning installed (they work fine in conjunction with MVHR).

[stubiff]

@jack

Yes, was thinking the more 'continuous' route rather than expecting it to cool in 30 mins.