Hello, all, I'm wondering if I can get a little help being convinced to do this... Background: Our house was built in 1980 with an air-source heat pump instead of a furnace. We live in Juneau, Alaska, which I believe has a design temp of -5*F. The heat pump was 36,000 BTU rated and had a minimum temperature of 32*F. The owner/builder of the house (he was a contractor) supplemented with wood, which must have been often because the backup resistance heating system tripped a load controller that shut off power to the stove, water heater and dryer. A couple years after the house was built the stove, water heater and dryer were converted to propane to free up electricity for a shop and MIL apartment to be built next door, tied in to the same 200A electrical service. The apartment is electric heat with propane for the stove, dryer and water heater. At some point after the house was sold to our previous owners, they had an 80% efficient, 105,000 BTU input oil furnace installed and replaced the wood stove with an oil unit (we started getting burn bans because of bad air quality in the 1980s from all the wood heating). Since that was obviously way too freaking big they had it downfired as far as it would go, so it is now a 79,000 BTU input furnace, so 63,200 effective (plus any stovepipe heat to the furnace room so let's round up to 70k to be safe).
Darn it, apparently my iPad submitted the thread instead of starting a new paragraph. Anyways, I'm looking to replace the furnace with a GSHP. Since moving in we have removed the oil stove and had the chimney removed, insulated the heck out of the apartment and purchased an electric car. I plan to do a lot more insulating/sealing work once the GSHP is installed because I'm already having issues feeding the furnace with enough air and can't go any tighter without worry. I would also like to replace the existing propane water heater (inside conditioned space) with an electric unit. I installed a Nest thermostat and I've been tracking the furnace useage. It's currently 10* with wind outside so it will run about 6.5 hours per 24 hour period to reach a 72* set point. Last winter we had a string of -10* days and at no point did the furnace run for more than 10 hours. Judging by that useage, I believe a 4-ton heat pump system with desuperheater should be enough to meet my needs; my big wildcard is that I would also like a heat recovery ventilator to be installed at the same time and I don't know how that affects the overall BTU needs (can the systems shut them off when it's marginal?). The old heat pump circuit is 50A and currently being used by a hot tub. I plan to get rid of that when the GSHP is installed. With the energy efficiency upgrades I did this summer, I'm confidant that I can use that circuit and still have enough power for an electric water heater to be installed back in. That's my baseline: I believe I need a 4 ton unit, HRV, electric water heater. I have a 50a circuit I can repurpose and a 20A circuit waiting for a water heater. I would prefer a variable speed system as my part of the world needs heat about 360 days a year, sometimes a good bit but often not very much. I do not believe I have the electrical capacity for auxilliary heat. My yard is not big enough to lay trenches but I have several good places to drill with reasonable access to the outside of the furnace room. I contacted three manufacturers back in October: Climate Master, GeoComfort and Waterfurnace. I never heard back from GeoComfort. Climate Master's local rep never showed up to an appointment to check out my house. The Waterfurnace guy just got me back an estimate today, three months after coming by. The estimate is for a 6 ton system with aux heat, trenches, hooking up to my 'existing' electric water heater and makes no mention of an HRV. The pump is not variable but the blower would be. What the heck? Is this what I should be expecting from an entire industry? I really could use some help here. I feel like I'm having to drag people kicking and screaming to give them money. What are my options for not dealing with any of these contractors, assuming that despite all this I still want a GSHP?
Don't know if this helps, but I found these two contractors in Juneau. Behrends Mechanical, Inc. Richard H. Behrends 1782 Anka St. Juneau, AK 99801 US 907-780-6766 behrendsmech@gci.net AI Modern Mechanical Engineers Shane Hooton PO Box 34258 Juneau, AK 99803 US 907-789-9320 shane@modern-mechanical.com www.modern-mechanical.com AI
Andy is a friend of mine who lives in Fairbanks: Alaska Geothermal LLC Andrew Roe mcmroe@acsalaska.net Office: 907-474-4001 Fax: 907-474-4015 Mobile 907-378-0849
Thanks, I will have to make a few more phone calls. Clearly asking the manufacuters wasn't the way to go!
I get those e-mails passed to me from manufacturers (for my area). Usually I never hear from the contact after getting in touch with them. It may be the perception that they are just tire kickers contacting them this way. I don't know.
Same here - about once a month I'm sent a "hot lead" from manufacturer site web inquiry...all tire kickers / rarely a reply to my follow up / nary a sale.
Got a response back from Behrends - they don't do residential. My quote was fixed. Now it looks like I'm being quoted $24,000 for a Waterfurnace 5 series with desuperheater. That's just for the unit + hooking it to our ducting. Does that seem high? I see quotes around here for that much including trenching.
Yes. It is quite high for my area (BC). But I'm quite high for other areas. If you take me fishing, I may just drive up there for less than that quote.
If I was driving my #$$ to Alaska, I'm pretty sure some Salmon fishing would be in order. Not that we don't have that around here as well.
One either has time or money. It seems never both. We have old friends in Juneau. Do the roads go through now? Or do you still need to go by boat? Hell this project is no good we would have to get passports. I like the old USA to CA rules better.
Still by boat. We're working on the road, maybe, don't really know... Our current budget climate is not good for the road project. I've started calling around and I'm working on trying to get quotes from the local Climatemaster guy. I'm also seeing if I can maybe get some other companies to do part of the work as prep, and maybe get somebody from elsewhere to install the unit. Who knows at this point. I've got another company in town trying to get me to install a new air source unit. From talking to the local guys, whom are definitely more knowledgeable sounding than the waterfurnace guy, it appears we're going to need some duct work now. Hooray. Our output necks down and then back up again for no reason. That should be a pretty simple fix. Unfortunately, I think we're also in line for a complete return duct replacement. At least I can get to most of it with a minimal amount of drywall work. Would anybody be willing to punch some numbers into one of the calculating apps and see how much vertical loop I would need for a 4 ton unit with desuperheater in zip code 99801? The Waterfurnace guy said 2500 feet, which is awfully similar to his horizontal slinky numbers (which were 2800 feet for a 6 ton unit). My ground is entirely saturated glacial gravel down several hundred feet and the water table is at about 10 feet. Frost line is somewhere between 32" and five feet, I hear conflicting numbers. Edit: I'm only asking about the numbers for verification. Also, I was told 3/4" tubing down the holes. I thought it was 1 1/2" tubing in 4" bores?
Generally 3/4" pipe is used for 200' deep loops, 1" pipe for 200-300', 1.25" pipe for 300'+. 1 1/2" loop pipe is rarely used or not at all.
If we assume: ground temp of 42° min EWT of 28° heating BTU of 40,000 ground conductivity of 1.75 then the loop design would call for 5 - 3/4" loops 200' deep. Which is 2000' feet of pipe. 2500' would give you better efficiency.
We'd be doing 400 foot deep loops here. Our average yearly air temperature, IIRC, is 40*F. Thanks, sounds like the tubing might be undersized but the loop length is about right.
