experience with portable heat pumps?

[briansandle]

I am asking about the type of portable heat pump which draws in two streams of air from the room. One stream is cooled and expelled through a vent hose, and its heat is transferred to the other stream which is returned to the room.

To replace the expelled air from the room air comes in under doors &c, eventually from outside the house.

When outside temperatures are cold, air may be expelled out at a temperature greater than the outside temperature, giving a net loss of heat to the house, compared to a simple electric heater of the same input power.

Has anyone any experience restricting the flow of outgoing air, or reducing the speed of the fan for that, to give the outgoing air more time to cool?

Thanks from Brian Sandle

[grumpy]

Lookup space coolers

[soundhill]

Thanks, this unit works as an air conditioner, too. The equivalent problem would be send to the outdoors air cooler than what it is drawing in from outdoors to replace it.

Most heat pumps have the indoor and outdoor air streams isolated from one another. One experiment I could do would be with the portable would be to make it into a two-hose system, to achieve isolation. But I might get icing especially in humid outdoor conditions.

Not quite sure where to look in your "space coolers".

The units I refer to have input power of about a Kw or less.

Brian Sandle

[soundhill]

ms of air from the room. One stream is cooled and expelled through a vent h ose, and its heat is transferred to the other stream which is returned to t he room.

entually from outside the house.

ure greater than the outside temperature, giving a net loss of heat to the house, compared to a simple electric heater of the same input power.

ng the speed of the fan for that, to give the outgoing air more time to coo l?

By giving the outdoor-going air more time to cool I would hope to have captured more of its heat to return to the room.

The pump draws in room air and sends it back into the room at temperature similar to or greater than human body temperature, at quite a fast flow. It has trouble heating the room much, though, on cold days when the outdoor air being drawn in is a few degrees colder than the expelled air to outdoors. Then the room is only being heated at the rate of input power, 900watts or thereabouts, less what is being lost, by sending to outdoors hotter air than replacement outdoor air being drawn in.