ASHP stupid question?

[BUDFORCE]

This thread will probably be short, but something I've been thinking about.

I get the principal of these, they work like an air conditioning system, but in reverse, so on the outside of your house youve effectively got a heat exchanger, which is taking what heat there is from outside, transfering that into your house, and making the outside even colder.

The colder it is outside, the less efficient they are because the less heat there is in the air to transfer.

Hopefully on the right track so far?

But, won't the air in your house be warmer than the outside air temperature?

So, wouldn't rather than taking the heat from the air outside, it could take the air in your house, warmer, more efficient, and just run that around in a loop?

Say extraction from one side, venting in from another.

Do they do this already? Am I missing something obvious?

 

[rodders]

There's some good YouTube videos on this, going through the process on a schematic.
Worth a watch.

 

[SimonR]

But, won't the air in your house be warmer than the outside air temperature?

So, wouldn't rather than taking the heat from the air outside, it could take the air in your house, warmer, more efficient, and just run that around in a loop?

Say extraction from one side, venting in from another.

Do they do this already? Am I missing something obvious?

The bit that does the heat exchange is the clattering, chest freezer size unit that lives outside your house. Would you really want this inside your house? Where would you want to locate it?

 

[Sinbad2000]

This thread will probably be short, but something I've been thinking about.

I get the principal of these, they work like an air conditioning system, but in reverse, so on the outside of your house youve effectively got a heat exchanger, which is taking what heat there is from outside, transfering that into your house, and making the outside even colder.

The colder it is outside, the less efficient they are because the less heat there is in the air to transfer.

Hopefully on the right track so far?

But, won't the air in your house be warmer than the outside air temperature?

So, wouldn't rather than taking the heat from the air outside, it could take the air in your house, warmer, more efficient, and just run that around in a loop?

Say extraction from one side, venting in from another.

Do they do this already? Am I missing something obvious?

Heat pumps don't generate heat, they just move it around (hence the pump part of the name). So if it takes in the air from inside your house, it will just chill that air right down and pump it out the back end. If you somehow vented this cold air to outside, you'd have to replace that air with a similar volume of air... which would have to come from outside - so no gain?

 

[alexakasloth]

What you are describing sounds like a heat recovery ventilation system.

 

[BUDFORCE]

Heat pumps don't generate heat, they just move it around (hence the pump part of the name). So if it takes in the air from inside your house, it will just chill that air right down and pump it out the back end. If you somehow vented this cold air to outside, you'd have to replace that air with a similar volume of air... which would have to come from outside - so no gain?

Ok yes thank you.

I understand now, if it was some kind of closed loop, yes as it vents the cold air, new air would need to come from somewhere....

I guess if the "new" air was dragged though your house to warm up before being cycled through the heat exchanger, you would still have net loss overall.

Thank you.

 

[Sinbad2000]

Ok yes thank you.

I understand now, if it was some kind of closed loop, yes as it vents the cold air, new air would need to come from somewhere....

I guess if the "new" air was dragged though your house to warm up before being cycled through the heat exchanger, you would still have net loss overall.

Thank you.

And that new air would do a great job of freezing your wife's toes on the way through

 

[sovietspybob]

For everything and more that you've ever wanted to know watch this guy, he has several other ones where he explains how and aircon works and the differences.

 

[Deleted User 298457]

For everything and more that you've ever wanted to know watch this guy, he has several other ones where he explains how and aircon works and the differences.

Love this guy.