Portable Ac with heat single hose for winter heating ?

[ecomodded]

At 7 minutes starts at COP

https://www.youtube.com/watch?v=kJnHeNpNU1E

This may help

https://www.youtube.com/watch?v=irD6Sj0KRrk

[ecomodded]

For those curious of the COP values at different temps

This chart gives a good understanding of what COP value your getting at various temperature , the COP rating on a Heat Pumps label is not its Maximum COP



In warming weather the COP climbs , cooler it lowers but still makes decent COP
numbers until its too cold then a new heat source needs to be employed.

I have little idea how this applies to the Portable one hose heat pumps. I think it may keep a steadier COP and work a little bit longer to heat the colder intake / infiltration air

[jeff5may]

Ok, let me clarify a bit. In a sense, both ormston and I are correct. The design looks horrible on paper. A traditional split system has all this latent heat flowing straight to where you want it. You can make a cool looking graph and calculate everything distinctly. The one pipe looks messy and super leaky and ineffective when you plot points and make diagrams.

The one pipe setup is a heat pump, just not a traditional or "proper" design. It isn't going to start from scratch and heat up a cold room quickly. The analysis on paper leads engineering types to believe that it won't do it's job very well. After all, there is no such thing as a free lunch.

However, the rig does its job well for the price and size. It is meant to be a supplemental heat source (or sink) anyway. When you put it downstairs or in a cool, dank basement, and it is cool or cold outside, the make-up air tends to fall towards the unit. This cooler air is heated and then rises to the ceiling and finds its own way up.

The utility of the unit comes from its ability to exhaust comfortable warm air inside the envelope in large quantities. Unlike a standard heat pump, this rig will keep pouring out the same temperature air when it gets frigid outside. Rather than using it's leverage to move raw Watts from one place to another, it extracts what you don't want (heat or anti-heat) from the indoor air and exhausts the waste outside.

This is where the unit can fool you if the whole premise is not considered. As others have stated, when it gets cooler outdoors than the exhaust air, the unit loses effectiveness due to the incoming make-up air. When a standard air source split unit starts losing efficiency, the condenser temperature drops and so does current draw. The one pipe setup will continue to draw the same power and the same temperature air will be spit out indoors.

In most situations, by the time the outdoor temperature dropped to this level, the one pipe system would not be able to keep the cold from creeping in, even if it was a split unit. Being under a ton of refrigeration capacity, it has its limits. As the Delta T between indoor and outdoor air temperature rises, the primary heat source will be called upon more and more anyway. If saving money is s major concern, a low ambient control could be rigged to cut power to the unit below a certain balance point.

FWIW, the Sub-Zero hyper heating air source mini split units act the same way: they force a higher indoor discharge temperature by speeding up the compressor. This lays waste to the COP of the unit. Useful heating is still achieved, but at great expense.

[jeff5may]

Originally Posted by ecomodded

For those curious of the COP values at different temps

This chart gives a good understanding of what COP value your getting at various temperature , the COP rating on a Heat Pumps label is not its Maximum COP



I have little idea how this applies to the Portable one hose heat pumps. I think it may keep a steadier COP and work a little bit longer to heat the colder intake / infiltration air

Basically, the one pipe unit will be more linear than the graph posted. The heat pump COP will follow indoor air temperature, period. It is going to spit out very close to the same temperature hot and cold air at a predictable difference in temperature. The system COP will follow outdoor air temperature minus exhaust air temperature.

This concept doesn't have the same measurement metrics as a traditional heat pump. Let's say you have the unit in a low spot in the home near a window. If you crack that window open just an inch, your make-up air will all come through that opening, and find the intake of the unit. The unit will find a new balance point at lower COP, but the warm air will rise up and away from the unit, and the rest of the home will (hopefully) hold more heat. Factor that one in on paper.

[ecomodded]

Thanks for further input were getting this nut cracked.

The arrangement

It will be exhausting cooler air out from the rec room floor via a low sucking cardboard vent attached to the side intake extended down near the floor to gather and expel the coolest room air and cycle the upper warmer room air for heat to drift upstairs.
It will be set 3 feet off the floor so the indoor fan will cycle the upper warmer air threw the indoor fan.


The temp

The temp difference from floor to 5 feet above might only be a 5* or 7* difference ( yet to be tested) but should still help its economy.
Every teak will help when its running 12 or 18 hrs a day on cold nights
Its 31 inches tall so when placed on a table to vent straight out , the room fan will draw air from about 65 inches off the floor or 5 1/2 feet.

~~~~~~~~

Tests

Today have been studying on fan speeds comparing the top name mini splits factory rating to a independent tests chambers results .

The results were similar to advertised

I found that with the compressor speed set on high the best COP at any temp was made with the Fans on high as well.
Because this unit has non inverter compressor it runs at full speed so the highest Fan speeds will provide the highest COP.
I should swap the 4 inch Vent plate for a 6 inch vent and gain the airflow COP it should provide.

The stove vent outlet plates cost $40 so it makes fiscal sense to swap it out to get the units maximum COP rating.
The last tweak I can think of a HRV but is too expensive at near 1000 dollars but I like the idea.


The basement and front doors both leak air the stoves overhead fan vent leaks 24-7 so most of those drafts will be used as the intake air for the exhaust.

With the unit running it will reverse the airflow instead of flowing out the cracks it will come in and out the AC although at a higher rate it at least will draw from the houses current losses.


I think its going to work out pretty well in this case


If you think of affordable tweaks let me know I'll try them out.

[ecomodded]

More food for thought

The units 1200w of input power to the compressor stays in the house as heat after its done its work.From what I read that will provide a 20% bump in heat output

A lot of the complaints with a indoor one hose AC's doesn't effect the units as much when in heater mode.

As a one hose heater

It works in its full COP cycle 24-7

It rarely will need a defrost cycle

Its air input draws from current warm air leaks cutting incurred losses further

The Compressor 1200w of power consumption heat stays in the house not outdoors like a mini split design.

Last but not least natural convection will flow heat up where its required instead of trapping it in the room

Its actually not as bad of a heater as it first appears

[ecomodded]

My last mind bender is how they rate the Btu / COP output.

Could be its measured Btu output done at room temperature or 44*f
It seems mini split manufactures use around a 7*c / 44*f outdoor temp to rate the COP values.

Possibly to get the fixed COP value they factor in the infiltrated air

I can't find info on how Honeywell or anyone Rates these units to a Btu output


Could be the Btu value is a factored value taking into account the outdoor 7*c / 44*f infiltrated air temp

Or its rated Btu output is for the indoor temps they are expected to be in.

Its low priced so it may pull off a COP of 2.7 maximum at room temp.

That also makes sense as its half the costs of the cheaper of the mini splits

The model is Honeywell HL14CHESWW

Its 14000 BTU cool output and 11000 Btu heating output suggests to me they have done factoring into its rating or it might just be the condenser size that changes the values between heat and cool.
I dunno

[ecomodded]

Originally Posted by jeff5may

Basically, the one pipe unit will be more linear than the graph posted. The heat pump COP will follow indoor air temperature, period. It is going to spit out very close to the same temperature hot and cold air at a predictable difference in temperature. The system COP will follow outdoor air temperature minus exhaust air temperature.

This answers my previous posts COP question

I see why now , remember reading that they measure COP in heat pumps by the inlet and outlet temps / indoor heat gain vs outdoor air temps.

So this units COP *should* be a accurate representation of its efficiency at around 7*c / 44*f or there about like with the outdoor splits COP measurement

That makes sense or the Btu numbers are next to useless / a advertising stunt.

It might not be 100% accurate but should be in the realm of its heat output COP @ 44*f outdoor air temps

I'm not sure of that but it sounds reasonable

Edit

I read the last statement wrong " The system COP will follow outdoor air temperature minus exhaust air temperature "

That throws a loop into my theory I thought I would measure outdoor air as the inlet and Btu heat as the outlet temperature

its sounding like a reverse COP math
I should be able to figure out Btu gain at 44* (or there about) with this system like with a mini split.


New math plan

I'll keep it simple and follow what was wrote above in the highlighted area

Lets say its 7*c outside and the vent blows out 2*c , divided is 3.5 COP

I'll try it again with more numbers

12*c divided by outlet temp of 2*c = COP of 6

Might be onto something I will have to take real numbers when its running and see what those are

That math my well be totally wrong Im far from a HVAC guy

Edit I need to convert it to Kelvin first

12*c to K = 285
7 to K= 280
2 to K= 275

COP @ 12*c outside and 2* from cold outlet = 12 - 2 = 10 COP

7 - 2= 5 COP

I'll try that with real numbers when I have them and do more research in the meanwhile

[DEnd]

Originally Posted by Ormston

Unless those other heat sources are outside the thermal envelope of the house you're stealing heat from one part of the house to give to another.
So no net gain.

The Net gain comes from the infiltrated air temps vs. The discharge air temps.

Basically the Unit brings in outdoor air at say 72ºF and discharges it at 32ºF, so basically there are 40ºF worth of BTUs in that infiltrated air. If we want the indoor air to be 76ºF then 10% of those BTUs are used to heat up the infiltrated air and the rest of the BTUs are used to heat up the rest of the house.

COP is the efficiency of the Unit itself not a measure of efficiency of the entire house. Basically the unit can cause a net loss of heat to the house (this happens when the recoverable BTUs are greater than the BTUs needed to warm the infiltrated air up to warm temperature) and the unit will still operate at its COP.

[DEnd]

Originally Posted by ecomodded

This answers my previous posts COP question

I see why now , remember reading that they measure COP in heat pumps by the inlet and outlet temps / indoor heat gain vs outdoor air temps.

So this units COP *should* be a accurate representation of its efficiency at around 7*c / 44*f or there about like with the outdoor splits COP measurement

That makes sense or the Btu numbers are next to useless / a advertising stunt.

It might not be 100% accurate but should be in the realm of its heat output COP @ 44*f outdoor air temps

I'm not sure of that but it sounds reasonable

Edit

I read the last statement wrong " The system COP will follow outdoor air temperature minus exhaust air temperature "

That throws a loop into my theory I thought I would measure outdoor air as the inlet and Btu heat as the outlet temperature

its sounding like a reverse COP math
I should be able to figure out Btu gain at 44* (or there about) with this system like with a mini split.


New math plan

I'll keep it simple and follow what was wrote above in the highlighted area

Lets say its 7*c outside and the vent blows out 2*c , divided is 3.5 COP

I'll try it again with more numbers

12*c divided by outlet temp of 2*c = COP of 6

Might be onto something I will have to take real numbers when its running and see what those are

That math my well be totally wrong Im far from a HVAC guy

Edit I need to convert it to Kelvin first

12*c to K = 285
7 to K= 280
2 to K= 275

COP @ 12*c outside and 2* from cold outlet = 12 - 2 = 10 COP

7 - 2= 5 COP

I'll try that with real numbers when I have them and do more research in the meanwhile

You're missing energy flows. The unit will operate at its COP regardless of outdoor temp. however in reality the added BTUs are only there if the temperature difference of outdoor air and the discharge air tempreatures is about 1/2 the temperature difference of the outdoor air vs the desired indoor temp (assuming there isn't a phase change of something in the air needed in there somewhere). Lets say outdoor temps are 72ºF and you desire a 76ºF indoor temp and the unit discharges at 32ºF The unit will operate at a 2.7COP but the actual COP of the house (with just this unit) will be ~2.48, because 10% of that energy will be needed to heat the infiltrated outdoor air to the desired indoor temps. Yes the BTUs output by the unit will remain constant regardless of the outdoor air temps but a part of those BTUs are unusable because they are "used" to increase the temperature of the infiltrated outdoor air. Take that energy flow into account and you will get much closer to what the COP of the system actually is.