I'm looking to replace my 80% forced air furnace with something way more efficient. (And then i want to add solar). I've looked at putting in a 95%+ Bryant + Bryant heat pump + zoning system, or a Daikin. I live in seattle so the climate is relatively mild. A few 0 days, but mostly in 20-40 in the winter (Oct-Apr). My questions: Will a daikin remove the need for a gas forced air? Is there a carbon footprint difference between the two solutions? What should I expect a daikin to cost? I've been given quotes that seem very high (more than a heat pump + 95 % + zoning system combined) I've read reviews that have said both systems are lousy and both are great. Looking for additional opinions.

I am assuming you are looking at the Altherma by Daikin. As a hvac/solar contractor have looked into them and they are quite impressive . Have not yet to install one and yes they are expensive. You are going to need to do the math on gas versus heat pump and electric rates. As far as the solar goes do you have enough area for the collectors and are we talking thermal or pv.

Nat gas or propane matters as does cost for either fuel and cost/ kwh. Heat load of the house as well.
based on the info you've provide so far your question is akin to "which car is best for my needs".
j

4600sf house, natural gas, of which typically a much smaller subset is being heated. I'm looking at the Daikin Altherma. Some people tell me it works great to -5F, some people have said that it becomes inefficient around 40. I'm not sure whom to believe I looked into geothermal but i don't have enough land and also have fairly restrictive property covenants For solar, i have a lot of roof space for panels that is facing almost due south. I live in seattle area which means there is rarely unclouded sun, but also the temperature is good for solar cells. I recognize it is hard to tell what

With the size of your home , you would probably need two systems, that would be real expensive. The published literature states down to -4F. A heat calc needs to be performed first to determine equiment sizing. A comparision needs to be made between gas and electric rates. Being that this is an existing home the challenges to retrofit to some other means may be not cost effective. Something like a Carrier Infinity system may be more suited for your needs. You can always add solar as a stand alone system to supplement your energy needs.

4600sf house, natural gas, of which typically a much smaller subset is being heated

How much of that is heated and how much do you need air conditioned?

I've never turned on AC in 5 years. It is possible my wife might want to, in which case it would be maybe 600sft max for AC. During the night about 1/5th or less will be heated; during the day perhaps half, which is why we want to put in the zoning. So the actual needed space to heat is much smaller than the full space.

The people that tell you the Daikin becomes inefficient at 40F are incorrect. It would perform excellently in Seattle.

acwizard already observed that due to the size of your home, you might need two systems. If that is the case you might consider the Daikin for your main space and a minisplit ductless heat pump for the bedrooms, possibly. That would give you a lot of natural flexibility as regards the 'zoning' you mentioned.
Electric heat in Washington is already low carbon because of our hydroelectric power, but once you are on electric, you always have the option of buying up to Green Power for a couple cents a kWh which would turn you solid green.

You might want to wait on the solar hot water because when you run the Daikin in cooling mode, your hot water will be nearly free. The rub is that happens in Summer which is the same time the solar would be kicking out the heat.

Bottom line is that you need to determine your heating needs to see what units will work for you.

I've already gone for the Green Power option here, but that doesn't reduce my guilt enough... I'm using a tankless Navien right now for hot water -- house used to have two tanks instead -- so that was a good shift.

i wanted to use solar for electric, so that i could offset the electric use of the heat pump (and everything else)

Well, with the gas money buying kilowatts for the heat pumps, you'll have even more green power usage to celebrate.

PV panels? Another good choice. With the 30% tax credits and WA incentives, paybacks are sitting around 9-12 years, depending.

How much gas are you using for heating right now?

yes, i'd love to put in pv panels. any recommendations on people who do that work/products to use?

for jan, i used 2360 kwh electric and 341.8 therm.

Posted By misha.seattle on 10 Mar 2011 01:44 AM
yes, i'd love to put in pv panels. any recommendations on people who do that work/products to use?

for jan, i used 2360 kwh electric and 341.8 therm.

Pv would be a good way to go, Sharp makes an excellent module along with Mitsubishi, Sanyo, Evergreen and Shuco just to name a few. The inverter choice would be Sunny Boy, Outback or Fronius. Installed costs from $7.00 to $12.00 per watt. Roof area will factor into sizing. Any additional charges over baseline is where solar is beneficial in reducing energy costs. Your home probably could be sized at 1.5 kw

Washington state has powerful cash incentives for made-in-Washington (MIW) solar equipment.

For example, the production incentive for general solar is $0.15/kWh
For MIW, the production incentive is $0.54/kWh - more than 3X as much.

Right now, the installed costs for "other" is about $5-$6 per watt, before federal credits.
The installed costs for MIW is about $9 - $10 per watt, before federal credits.

Solar panel outputs in Washington vary, depending on a lot of things, but a starting point is to multiply array size by about 1,000 for yearly output. That means a 4.8 kW array will yield about 4,800 kWh total over a year.

for jan, i used 2360 kwh electric and 341.8 therm.

If 20% of the gas went up the chimney due to efficiency, then your heating was 273 therms for about 27 Mbtu, which represents about 3200 kWH at a COP of 2.5

273 therms = $300
3200 kWh = $320

Just about a wash in the coldest month we've had in a while. Since that is just about as low as the COP gets, you should do better in all other months.

A single Daikin unit might even handle your needs if you are willing to go on resistance heat at peaks to avoid the cost of putting in a second unit, although the flexibility of having the additional mini-split ductless system is really great.

thanks, that is really useful. i'm trying to figure out a price for the altherma still (seems difficult) and find a solar installer. I like the idea of using MIW. I don't mind spending a bit more cash up front for the long run, since it is a long term project.

Any suggestions on companies/contractors that do a good job? I'll also ask PSE, although I've had mixed luck with them.

I like the idea of using MIW. I don't mind spending a bit more cash up front for the long run, since it is a long term project.

The cost seems huge upfront, but the payback for MIW is actually faster than the alternatives or the Made-in-China, etc. You are limited to a maximum reimbursement per year of $5,000, but that would represent a 9 kW array.

Best as I can figure the Altherma is in neighborhood of $12K (+ some install). A mini-split ductless system is about $8K installed. If you are moving from gas, you might have some electrical costs and some ducting changes. Because you have some ducting already, you might see if it is feasible to install the Altherma first with minimal duct changes. The mini-split ductless can go in later after you have determined if and where you need it.

Any suggestions on companies/contractors that do a good job?

Alternative energy is somewhat jurisdictional. In general, you want to get a contractor who has experience in your jurisidiction (e.g. City of Seattle, or King County, etc) and I'm North so you're on your own, but make sure they have experience and that you talk to the owners of past projects. Get multiple bids.

I'll also ask PSE, although I've had mixed luck with them

I don't know if they can recommend any particular contractor, but you will be working with PSE representatives anyway over the grid-tie issues.

Misha.Seattle,

The Altherma can eliminate the gas forced air if you want to do radiant throughout.  You *could* run the Altherma as a chilled floor if you're looking for some cooling, but somewhere along the line you'll have to figure out dehumidification as well.  Considering that you rarely turn on the A/C, the occasional chilled floor use might be an option.

As everyone else has said, you'll need a heat loss calc.  But, if the house is well insulated, you might be able to get away with just the Altherma, or use the Altherma as primary and use the Navien you already have as the backup heat source.  This is the configuration we're running now (Altherma/Navien) in a climate much colder than Seattle, on 6300+sqft of conditioned space including the basement.  The solar thermal can be plumbed into the solar option of the domestic hot water tank from Altherma.

Victor
www.ecobuilthome.ca
A 4350sqft Cold Climate Net Zero Energy initiative