A little education about heat pumps needed.greenspun.com : LUSENET : Countryside : One Thread
I'm hoping some of the good folks here in Countryside can educate me a bit about heat pumps for air conditioning and heat in a house in North Florida.
The reason I'm asking is that the home inspector I hired to look over the place my wife and I are buying found that the air/water exhange type heat pump in the house is probably on its last legs (it's seventeen years old) so I managed to negotiate having it replaced at the seller's expense as part of the contract of sale. My responsiblity in that area is to find the company to do the work and choose what I want to have installed. About all that I really know is that I don't want a water to air exchange unit seeing as how we're four years into a drought and who knows when it's going to end so running the pump constantly to keep the house cool would cause me a lot of anxiety.
Anyway, knowing what I don't want doesn't tell me what I do want. What are my options and what makes one a better choice for North Florida than another one? I'm hoping to keep the purchase and installation as close to $3,000 as I can since I have to pick up anything over that amount.
Thanks in advance for any advice or insight.
-- Live Oak (email@example.com), September 01, 2001
I've had heat pumps in two houses. The efficiency depends on the number of seers ~ the higher, the better. Yes, you pay more for more seers, but I think it's worth it! Mine have been 12 seers. Comparing the bills for heat/air to an all electric house, well, there is no comparison. The heat pump is MUCH less. Comparing price is difficult when we all live in different parts of the country.
The down side ~ The outside unit goes on first and then the unit in the house goes on. The outside unit is loud. Don't put it by your bedroom! If your patio, or area where you sit around is near the outside unit, it's not very quiet for conversation.
-- ~Rogo (firstname.lastname@example.org), September 02, 2001.
Everyone uses air cooled heat pumps here in the southwestern deserts. Cost is about $1K per ton for a 10 SEER. They work great.
-- Joe (CactusJoe001@AOL.com), September 02, 2001.
Thanks for the responses but I'm clueless as to what a "seer" is? Are they cooling coils or what?
-- Live Oak (email@example.com), September 03, 2001.
17 years is an OLD system. The compressor (in the outside unit)is the weak link, it'll last 12-14 years. The coils and blower tend to last much longer. If the compressor is old, negotiate to have it replaced.
-- Joan Murray (firstname.lastname@example.org), September 04, 2001.
Live Oak, it really does matter on your location and your humidity level. Areas of high humidity, like near coastlines, forest lands and lake lands, pretty much rule out heat pumps, from what I hear. They are cheaper to run, but they do not control the HUMIDITY level, which makes a humid area so hard to live in. If you are in the desert, mountains, etc. where low humidity is the rule rather than the exception, give them a look. You describe the area as North Florida, not the best location for a heat pump, but ask around, improvements may have been made that make my advice full of it. Hope this helps.
-- j.r. guerra (email@example.com), September 04, 2001.
Thanks for the heads up about the humidity I'll have to be sure to ask about it when I start making the provider calls. Heat pumps are very common here in North Florida as every house I've lived in for the last fifteen or twenty years or so has had one but I never really paid any attention to them before since I didn't own them.
The work that's going to be done is pretty much to completely replace the old water to air exchange system with an air to air exchange system. Hopefully won't have to replace the ductwork but the compressor, coils, blower and everything is going. The geothermal stuff really looks nice but I suspect that the price tag will be way out of our range.
-- Live Oak (firstname.lastname@example.org), September 04, 2001.
Live oak, talk to a geothermal heat pump person for more info. I am not sure I understand what is in place at the house already. You say it's got an air/water heat exchanger. If this is what I think it is, it will either be a closed loop or an open loop. The open loop is slightly more efficient, but he closed loop is still much more efficient than any other aircon system.
Open loop takes ground water, or pond water or whatever, and runs it through the heat pump, then either off onto the ground, or into a return well, or a creek.
The closed loop runs water around and around through a loop of pipe: either down a well and back up, or more commonly through several hundred feet of pipe, buried about five feet deep (where I live)
I installed an open loop ground source heat pump (also known as geothermal) four years ago. The MAIN REASON I installed it was for humidity reduction, so I don't understand j.r.'s statement about humidity. In fact, on the rare occassions when I have to run the heat pump for cooling, the house feels way cooler after just ten or fifteen minutes, even though the temperature hasn't changed enough to affect the digital temperature readout. (one degree increments).
If you already have the buried pipes of a closed loop system in place, the cost of replacing the "unit" itself should be similar to the cost of an air to air heat pump. One of the biggest expenses of a ground source heat pump is the cost of trenching for the underground pipe. But do check the seer for the air to air vs. ground source. Here in Oregon, the ground source is WAY more efficient in the winter. When outdoor temps are in the forty-five degree range or warmer, the air to air has an efficiency of 200-250%. When the temp gets below about thirty-five degrees outside, however, the air source has an efficiency of about 100%. My ground source has an efficiency of 395% REGARDLESS OF OUTDOOR TEMP. I unfortunately don't know how much more efficient the ground source heat pump would be for you for aircon, but I suspect it would be significantly better.
-- jumpoff joe (email@example.com), September 17, 2001.