Does anyone have an air to air heat pump... and how is it coping with the cold temps...

[richardc1983]

I have air to air heat pump that heats my flat... its -5C out and not having any problems maintaining the indoor temp of 22-23C. Defrost cycles have been approx 1 every 3 hours of constant running however the unit is happily ticking away and not working that hard.

When temps drop below 0C it doesnt have an electrical strip heater of any sort, it keeps on going down to -15C however output does start to drop off the colder it gets upto -15C.

Were very happy with it... its an LG system...

Heres some videos...

 

[richardc1983]

Vid 2

Vid 2

 

[richardc1983]

forgot to mention....

The system is purposely oversized so as to allow for these cold conditions so we have the extra kick if we need it!

 

[penguinsoup]

interesting question...

At my last house I had a heat pump, and it had some similar issues. At one point I had to kick on the emergency heat part of the system, but that later went out.
I know generally that is how they seem to function, not putting out the warmest of air in very cold temperatures, but after the e-heat went out, it was found that a circuit board or something similar went out.
My friends who also had a heat pump had the same issues with theirs, with the exception of the part going out. I have been told that is generally the nature of the beast.
I know I'm not really being of any help here, but more sharing my own heat pump experience.
Best of luck,
P

 

[supersurgilator]

My grandparents have a Janitrol packaged heat pump in their moble home. The previous owners would go to Florida in the winter so never used the heat. My grandparents soon found out that when the temps got below 40 it would just kick off all of the heat. After a couple of service calls, they found out that the strip heat which is supposed to kick in once the heat pump shuts off at 40 degrees had never been hooked up. But the heat the strip produces is still pretty lethargic because as my grandpa said, the house wiring in the circuit breaker didn't have enough power to hook both of the heat strips up, only one. I'm so glad we live in an area where we have natural gas and can have furnaces.

 

[richardc1983]

The technology is only for inverter systems, these have a compressor that ramps up and down based on load requirements.

Fixed speed systems would not heat below perhaps 0C so needed backup heat.

The modern split systems are fanstastic...

In New Zealand they have the same systems optimized for condtions there.

At -25 they say it will still deliver full heat output which is fantastic really...

REad this for info on the technology that is available now... I dont think there is a market for the split systems in America so they still use central systems which have the old technology.

HyperCore Technology // Mitsubishi Electric

 

[appnut]

I have a Trane, the 2nd one for my house, purchased March 2002 and is TOL. My previous one was a bilder's grade RUUD. I've been pleased with both. My heat strips do kick in when it gets close to freezing and when it gets 25 degrees F (I don't know what C is), it starts to struggle and the strips kick in. But it has managed to keep me comfortable even when it's 5 degrees outside and I keep my indoor temp at around 68 degres F.

 

[toggleswitch2]

The heat-pump I'm familiar with (Carrier brand) works until about 10*F (-12*C), at which point the resistance electic heat coils need to be energized.

 

[hydralique]

Split sytems are actually the most common form of HVAC in American homes. So long as the condensing unit is outside and the evaporator is inside it is considered a split system, regardless of whether or not it uses a heat pump, resistance heat, or a gas/oil furnace. Package units are used mostly in commercial rooftop installations, or mobile homes as noted above.

 

[toggleswitch2]

I believe this is what is meant by a spilt-sytem overseas.

We'd call that a split-ductless system as opposed to a split central / ducted system.

http://www.mehvac.com/products/category.asp?ProductCategoryID=24

 

[brisnat81]

Steve, thats correct.

We call that a Split System.

A ducted split system is purely known as a Ducted or Central AC system.

We've got two split systems in our place and between the two of them they do an admirable job of dealing with the 35degC 85% humidity days in summer and the Mild 5degC winter nights.

 

[toggleswitch2]

There is a market here for spilt-ductless sysems, that is small but ever-growing. Our style of double-hung sash windows allows for window air-conditioner affectionatelt called "Winodw-rattlers", ostesnsibly because they are quite noisy!

We are slowly learning how quiet, efficent, effective and versatile (they are heat-pumos as well) the split-ductless units are. They are woefully expensieve to have installed at this time.

I'm seeing them more and more in finished (inhabitable) basements which typically don't have enough or large-enough windows to "support" /allow for a window unit.

http://www.bestbuy.com/site/Air-Conditioners/Window-Air-Conditioners/abcat0907005.c?id=abcat0907005

 

[toggleswitch2]

Please pardon my editing skills. UGH!

 

[tolivac]

Not using my Lennox Ac-Heat pump at this time-its a BOL model-The heat pump function is rather inefficient and inadequite.Use electric space heaters instead.The Lennox unit works great as an AC in the spring and summer.But it is a poor "heater".

 

[toggleswitch2]

Actually doesn't a heat-pump use 1/3 of the energy to do the same job as electric resistance coils?

Dont let the cooler air-outflow temperatures(oftern no higer than body temperature) fool you.

Are any potential saving perhaps from heating fewer spaces and to a lesser degree?

 

[tolivac]

My saving from the portable heater is considerable!!I am not trying to heat the whole house.If I use the Heat pump I have it would cost around $200 per mo.The heater its less than $150.If I had a BETTER heat pump would use it-In one house I lived in the place had a Trane system-best HVAC system I had ever used.Worked great as an AC in the summer and an excellent heat system in the winter.That Trane worked even when there was 2 Ft of snow around it!Had to shovel the snow from the outside unit.The resistence back up heat hardly came on.The power bill was under $200 per mo.Would like to have a Trane in the place I have now--but it would cost about $6000.

 

[richardc1983]

Yes thats correct, they are 300% more efficient than electrical space heaters or coils... some of them are 400% more efficient.

An electric heater is 100% efficient, the air blown out of them is cooler than would be blown from an electric heater but they are much cheaper.

 

[dj-gabriele]

At my parents' we have split air conditioners in all the bedrooms, with a single outside unit, changing from the previous three separate machines with the 3 separates condenser outside units.

The EER for cooling isn't high, stated as 3,62Wcooling/Welectric (A class enegy) and COP for heating 4,16Wheatuing/Wectric, also A class energy but not so high. The machines, Panasonic, are made to be able to continue heating up to -10°C but since we never had temperatures so low in our town, we never had problems. It's stated that at -7°C the output is 75% than total at 7°C. But, I must say that I never had problems even on coldest cold that was -2 in our town Plus we have hot water central fired heating with aluminum radiators, so heat is never a problem, except in summer when the old A/C halted because of internal overheating with temperatures of 45°C in the shades...

 

[richardc1983]

dJ-gabriele what you have is a multisplit system, the disadvanatage of that is that you cant run each room in separate modes they all either have to be heating or cooling.

Not good if you have one side of the house that requires cooling due to sunlight and the other side heating.

I have multi system installed.. purely on space outside that was lacking.