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jeff5may · 04-08-16, 03:43 PM

You can do that with pretty much any system. The feature you are referring to is a desuperheater hx. It is plumbed in directly after the compressor in the refrigerant loop, before the reversing valve. It always sees the hottest temperature gas leaving the compressor, regardless of whether the unit is heating or cooling.

The opposite is not so easy. You cannot just tap into the compressor suction line and cool water with that stream of refrigerant. The lion's share of the cooling capacity is realized as the refrigerant is changing phase from a liquid to a gas, immediately after it squirts through the metering device. The suction end of the cooling coil (evaporator) is opposite the metering device end, so by the time the refrigerant reaches the suction end it has expanded. 99% of the heat has been absorbed at low temperature (latent heat transfer), and the remaining heat (sensible transfer) occurs by the gas changing temperature. Even with low counterflow heat exchange, there isn't much left to be had.

Added to this conundrum is the reversible nature of the heat pump. If the unit you choose doesn't change direction between heating and cooling modes, it is easier to directly rig in a chiller circuit. If the thing changes direction, you would need a dedicated chiller circuit plumbed in that short-circuits the reversing valve. Either way, your chiller is going to rob capacity from the cooling circuit one way or another. Whether or not that matters makes a difference as to your options. Also, the chiller circuit would be a slave to some other heating or cooling demand in the house.

As far as Hot potable water and freezerating go, they are usually a much smaller load to satisfy than the space heating and cooling needs. Other ecorenovators have toyed mercilessly with these comparatively tiny loads, and had resounding success. A run-of-the-mill dehumidifier can be modified to simultaneously make plentiful amounts of cold space and hot water, consuming about 250 to 300 watts while running. Maybe more power than a TV running, but definitely less than a desktop PC running. In comparison, most whole-home a/c units draw at least 2000-2500 watts while running.

I hope I didn't confuse you too much in this post. If so, just read through some previous threads. Many have been where you are now in their own struggles, and it takes a good amount of planning to get what you want out of your system. Superior efficiency is all in the figgerin', so to speak.

04-08-16, 03:43 PM	#15
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	You can do that with pretty much any system. The feature you are referring to is a desuperheater hx. It is plumbed in directly after the compressor in the refrigerant loop, before the reversing valve. It always sees the hottest temperature gas leaving the compressor, regardless of whether the unit is heating or cooling. The opposite is not so easy. You cannot just tap into the compressor suction line and cool water with that stream of refrigerant. The lion's share of the cooling capacity is realized as the refrigerant is changing phase from a liquid to a gas, immediately after it squirts through the metering device. The suction end of the cooling coil (evaporator) is opposite the metering device end, so by the time the refrigerant reaches the suction end it has expanded. 99% of the heat has been absorbed at low temperature (latent heat transfer), and the remaining heat (sensible transfer) occurs by the gas changing temperature. Even with low counterflow heat exchange, there isn't much left to be had. Added to this conundrum is the reversible nature of the heat pump. If the unit you choose doesn't change direction between heating and cooling modes, it is easier to directly rig in a chiller circuit. If the thing changes direction, you would need a dedicated chiller circuit plumbed in that short-circuits the reversing valve. Either way, your chiller is going to rob capacity from the cooling circuit one way or another. Whether or not that matters makes a difference as to your options. Also, the chiller circuit would be a slave to some other heating or cooling demand in the house. As far as Hot potable water and freezerating go, they are usually a much smaller load to satisfy than the space heating and cooling needs. Other ecorenovators have toyed mercilessly with these comparatively tiny loads, and had resounding success. A run-of-the-mill dehumidifier can be modified to simultaneously make plentiful amounts of cold space and hot water, consuming about 250 to 300 watts while running. Maybe more power than a TV running, but definitely less than a desktop PC running. In comparison, most whole-home a/c units draw at least 2000-2500 watts while running. I hope I didn't confuse you too much in this post. If so, just read through some previous threads. Many have been where you are now in their own struggles, and it takes a good amount of planning to get what you want out of your system. Superior efficiency is all in the figgerin', so to speak.