i,m new to this vrv game !

[Peter_1]

How, how, ... we heat our offices with a PUHY. A COP of 3.5 you said???
If you're satisfied with 18°C inside when ambient is +/- 10°C perhaps???
Calculate once at -10°C outside and 22°C inside. While running, the COP is then perhaps 2 or less but when it goes each 20 to 25 minutes in defrost, well... ou're average COP is shrinking like snow in the sun.
When we need to calculate for heating, we always take the 1 st figure in the manual (evaporating at -10° instead of 0°C or 7,5°C) Then we're sure that out heatpump has enough power to heat the building when the heat-losses are the greatest (outside -10°C when they need 22°C in the building)
That's evaporating in the best case at -14°C or -15°C. The moment you need the heat the most, nature is giving almost no energy anymore. Evaporating at 7,5°C is not a realistic figure. And when it goes in defrost, the fan is running at a very low speed, you will the cold coming out the units and all that cold has to be warmed up afterwards.
This is the second year we heat with the PUHY and we seriously think to install a central water heater, fired with gas and with litlle duct water heaters installed in the excisting ducts.

[benncool]

Yes Peter hit the nail on the head. When you get into outdoor temperatures that are below 0 deg C then heat pumps and thier COPs really are out of the picture.

It is a great concept to be able to move heat from the outdoors to the indoors using the principles of refrigeration. But when there is very little heat outdoors to move indoors then the whole theroy falls apart.

It is kind of like eating a bowl full of lettuce and calling it a hearty meal.

[Peter_1]

This has nothing to do if Benncool is an American or not. This is only a personal view. I think some better don't read alt.hvac anymore because they slowly taking over the very bad habits of some there without realizing it themselves.

We, ...and we're not Americans, installed in our offices a PUHY with a separate kWh counter on it, have the practical experience now with it each day.

But from next winter on, we will only use it for cooling and will install a gas burner before the real cold comes.
That will be much cheaper to heat.

Another one:
When you install a heatpump in your house, shop, house... and you uses it as your primary heating, they refund you a certain amount.
When everything is installed, someone of the electricity company comes - in this case Marc I know realy well- to check if you indeed have installed a heatpump and sign the papers then afterwards for the refunding.

Marc's wife has a shop and he needed an airco for this. He contacted us and we installed it.
He heats the shop now with gas and installed an only cooling unit.
He's seeing each day that heatpumps are not that efficient as the manufacturers and his boss (the main Belgium electricity company) promise.
A heatpump is a nice piece of technique and a good example of using the nature resources ....to a certain level. If you go below that level, then it's not economic anymore.
As long as you have a source of above 5°C, then it's OK.

When we build our new house 12 years ago, I installed two heatpumps air/water. I modified a lot to increase efficiency.
After two years, we installed a central gas burner and since then, we're heating much more economically (+/- half the price!!) and... we finally had comfortable temperatures inside our house.

[Latte]

What is this alt.hvac i keep reading about

Regards

Raymond

[rbartlett]

newsgroup alt.hvac used to be THE place to dicuss..then came fridgetechs' discussion then this..

no alt.hvac is frequented by mainly redneck neocons domestic hvac'ers who flame anyone en mass who dares to disagree with their out of date backward way of thinking..i positively enjoy the place..;-)

cheers

richard