Heat pump SEER rating

[Commander Kinsey]

Indeed. Yet another con. Pretty annoying when your 2TB drive is 1.8.

[trader_4]

Best to take a look at the cost of electric and how much you use the unit, what it costs to run. Makes no sense to me to buy a 20 SEER unit that cost $3000 more, if it takes 30 years to get the money back. The unit will probably be kaput in half that time. I suppose it makes sense to some worried about their carbon footprint.

[Jane Black]

Of course it does, it’s the first hard disk seen on the PC.

No it does not. The lines specifying the formatted capacity are clearly using 1,048,576. byte megabytes.

[Commander Kinsey]

Can you not understand that one unit may be better at the regulation test temperature, but the other unit may be better at a wider range of temperatures?

As an analogy, take car A and car B. Car A gets higher miles per gallon on the tests. But when you drive it a little bit faster, it burns huge amounts of petrol. Car B burns more at the test speed, but doesn't screw up when you drive faster.

[Commander Kinsey]

BTU divided by watts is damn stupid. That's why I prefer COP. It's unitless. It's the ratio of power in to power out. Very easy to understand, I use 1kW of electricity and get 5kW of heat. Therefore COP is 5.

[Commander Kinsey]

The USA has snowy parts does it not? Have they not realised you can reverse those AC units?

[Commander Kinsey]

A good excuse to burn loads of fossil fuels and piss off the treehuggers. I love watching the flames in my gas boiler.

[Commander Kinsey]

The Panasonic I quoted ain't for a window, it's the wrong shape. But it's a single unit. I have no desire to have units all over my house. I just want to heat one room and the heat or cooling flows between the rooms through doorways.

[trader_4]

Maybe to you, but not to the industry, the companies that build and market them. The "split" refers to the fact that it's not a single unit in a window type AC, the condenser and evaporator are in separate units.

If you have a two stage unit, it will run more frequently at the lower output on mild days. That helps move more air around, equalize temperature, get more humidity out, etc. But the problem is that two stage costs considerably more, I looked at it, decided it was not worth it.

[Commander Kinsey]

Agreed. When I'm ready to buy I'll list many of them in a spreadsheet and look at cost, reliability, SEER, etc, etc.

[trader_4]

I doubt it, because what changes is the COP, the higher COP units that cost more to build, should have curves that are better across all temperature ranges. It's thermodynamics thing. Which is why I said if you have something to show what you claim, that a lower SEER unit can cost less to run in some environments than a higher SEER unit, I'm sure we'd all like to see it.

That likely doesn't exist either. A Porsche sucks at MPG across the range, a Honda, even one of similar size, gets significantly better MPG across the whole range where both cars can operate. You're not going to find a magic speed where the Porsche somehow takes less fuel to run.

[trader_4]

Sure, we have heat pump systems here. But not in the really snowy parts though, because it gets too cold and the heat pump systems don't perform well, other solutions, eg nat gas or oil are used. And I don't mean super cold places either. In the NYC area, for example, I've never encountered a heat pump system. There are a very small, insignificant number, but AFAIK, only ones using geothermal, not air ones. They are common in the southern parts of the country.

[Rod Speed]

It was well after that.

And when its so variable time of day wise so it doesn't even affect the peak power demand.

Lie I said barking mad.

That's not quite so bad given that a surprising percentage of household water usage is to water stupid lawns and gardens.

A few towns of ours are currently having to have their entire water supply brought in in f****ng great tanker trucks. Makes no sense to be tipping that on the ground.

Sure, but it does happen at times even tho the place is usually very soggy.

That's not actually true with non industrial towns.

Doesn't work here, we have street signs about the bans.

She's right and that's why she poisoned the cats.

[Bob F]

It is exactly what heat pumps do.

[gfretwell]

It could be a wall pack like you see in motels, A Bard Wall hanger like they use on construction trailers or a ducted package unit like you see in a mobile home. They can be pretty efficient, the government just doesn't say they have to be.

[Ralph Mowery]

I have a heat pump. It does the heating and cooling.

I live about 1/3 of the way up from the bottom of the US. We do not usually have very many days where it gets below 15 deg F.

Heat pumps loose efficency below about 25 deg F. Around 15 deg F they are really poor and probably cost as much as resistive electrical heat to run. They usually have electrical heating elements in the inside duct work to help when it is very cold.

That is the reason that most of the Norther states where it gets to near zero F and lower the heat pumps are not used . It is usually more efficent and less expensive to use other forms of heat.

I have never checked the price but I would think there should not be much difference in a heat pump and plain air condition. I would install the heat pump and another form of heat.

There are some units called a gas pack. They have natural gas for the heat and electric for the AC.

[Clare Snyder]

GSHP systems work well - well below zero F. Ground Source Heat Pumps. Early ones pumped water from a well. Most current units run a glycol loop - some use horizontal loops but many now use vertical as they need less real estate. Getting pretty common up here.

[The Natural Philosopher]

Oh? Where does it go off to?

[alan_m]

As a matter of interest how does the (air) heat pump technology overcome the problem with freezing up.

At some point the pump is extracting heat from cold air reducing the temperature of the "exhaust". If there is enough moisture in the air it will start freezing making the heat pump less efficient. Once frozen, and in a long cold spell of weather, unless the icing up is removed the heat pump may not be providing any usefull gain. Does de-icing rely on the efficiency dropping and so the external box is being heated by the supplied power?

[The Natural Philosopher]

As with most green energyu projects, they let you down when you need them the most...