Sanyo 24KHS72 AC/HP DIY install project

[cholcombe]

AC_Hacker, it's funny you should mention that. That's the unit I settled on first. I talked to the local HVAC company and they said oh.. we only install Mitsubishi units. I said ok fine as long as I can get replacement parts and the efficiency is comparable. If my quote today is expensive I might just buy that Fujitsu unit online and install it with my dad.

[AC_Hacker]

Originally Posted by cholcombe

If my quote today is expensive I might just buy that Fujitsu unit online and install it with my dad.

Xringer did a great job of detailing the tools & procedures to do the install.

If you have relatives or friends that can help you or loan you the tools, you are just about home free.

If you decide to buy new tools, you could sell them on ebay when you're done. Xringer took that route, but by the looks of it, he's become pretty attached to the tools.

Also make sure that you understand warranty conditions before you DIY.

Good luck, no matter what you decide to do.

-AC_Hacker

[cholcombe]

Yeah... looks like I'm going to be installing it myself. The company said they wanted $3,000 to install the system and it would be a 'one day job'. What a total rip off. At least I know how much I'm saving now . Thanks XRinger and AC_Hacker. This thread has encouraged me a lot. I'm going to buy that fujitsu Halycon 15RLS system. The plus side of that heating company coming out to give me a quote is now I know where to locate the air handling units and also how much I'm saving

Edit: I should also note the guy told me I could do a 12,000 BTU heat pump and it would heat my office and kitchen. He also said if I bumped it up to 18,000 BTU, a good portion of the rest of the house would be heated as well. So I think for a few hundred more that sounds like a good idea.

[Xringer]

Was that $3,000 in addition to the unit cost? Your total cost?
Please break it down for us.

Remember, with inverter technology, it's a variable speed system, so if you buy
too many BTUs, it's not a problem, the unit will just run less power on mild days.
And be able to easily cool or heat the same areas on those extreme days.
My Sanyo uses about the same power as a small window AC, when it's just
maintaining the setpoint on mild days like this one..
It draws more power when we open up cold rooms to the rest of the house, or turn up the heat a bit.


If you can afford it, get all the BTUs you think you will ever need..

If the step up from 24,000 ($2211.00) to 36,000 ($3270.00) wasn't such a jump in price,
I would have gone for the 36k..
(Those are today's prices).

[cholcombe]

Xringer, sorry yes I was unclear. Let me break this down better. The guy quoted me $5800 total for the install. He said it was $2300 for the unit and $3500 for the labor.

Thanks for the tip about the inverter and btu's! That's a very good point. Also these units quality for a federal tax rebate and my local utility gives us a $400 rebate on top of that. Sweet!

[Xringer]

That was for 3 zones, right??

Yeah, $1,000 to install, $1,000 for the electrical work & $1,000 for the patio guys to build the pad, and $500 for line-set covers, screws, & coffee etc..

[MN Renovator]

Don't forget permits. Some places have unbelievably high costs to pull them, especially when it can be multiple permits for some HVAC installs(electrical, nat gas for furnaces, plumbing for burner condensate). I realize a mini-split doesn't have as much but the permit for electrical could be high and they might just tack on the fees for the rest of the permits they aren't pulling as one standard charge. $3500 for labor, most is probably going back to feed shop, administrative, the person who answers the phone, and the boss.

-Oversizing, it might use less power the inverter runs at a lower speed but the ratings for both heating and air conditioning efficiency go down with the larger capacity units. The idea for my own usage would be to undersize to my bare minimum capacity and make up for it with natural gas. In my case natural gas is cheaper than even the best heat pumps though below freezing(very cheap gas here), so I'd be doing my install primarily for the air conditioning. I'm slowly drifting away from the idea though because I might just toss a 16 SEER(single-stage) A/C and a new 95% multi-stage(or small as possible) furnace in to replace my current 76$. The thought of a $3500 labor charge for a mini-split makes me wary though because even that seems expensive to me for even a whole furnace and A/C together.

An accurate heat load calculation for the lowest winter dry bulb temperature should be done to really determine how big of a dent it will take. ...or the lowest temperature the unit is designed to efficiently produce heat and use the oil for when the unit can't keep up. Also consider the output that the unit you are considering can produce and the cost to produce it when you are calculating the cost savings and unit sizing.

[AC_Hacker]

Originally Posted by Xringer

If you can afford it, get all the BTUs you think you will ever need..

It is true that the inverter technology (AKA: variable speed compressor) will give you greater flexibility and efficiency.

However, it is also true that the larger compressor will have more internal friction per revolution, and a properly sized unit will cost less to operate than an over-sized unit. If you doubt this, look at the HSPF for various size heat pumps from the same manufacturers, same model line, different capacities...

With fossil fueled heating, the method was to do an rule of thumb estimate (usually based on square footage, totally ignoring insulation, fenestration (AKA: window) heat gain/loss and infiltration, then increase the estimate by 50% so that there would be no call-backs.

With vapor compression heating, it is different, bigger is not better.

One step that gets overlooked is to know ahead of time what your heat loss actually is.

[* * Gary, at Build It Solar has a good Home Heat Loss Calculator that will get you a very close to your actual heat loss * *]

Most people imagine that the heat load is a flat line, but it is not. It is a statistical distribution, like a bell curve.

Here is a bell curve I happen to have in my archive. For this discussion, the shape is important. Ignore, if you can, what the curve is actually about:

So it is apparent that throughout the winter, the warmest temperature days and the coldest temperature days are few, and that the "average temperature days" are the greatest.

To size your heat pump for (or worse yet, more than) the coldest 2% days would mean that you would be paying in inefficiency during the more numerous average days.

The best plan is to size the system so that it would provide sufficient heat for all but the coldest 2% of winter days, when axillary heat would be called upon to fill the gap.

Fossil fuel thinking doesn't work well for vapor compression heating.

I've talked numerous HVAC techs and some, but not most, understand this.

-AC_Hacker

[cholcombe]

hahah, no XRinger that was for 1 zone. I bet they charge $300/hr for labor. The guy also told me there was no permits needed for this job. I also have enough space on the circuit breaker for a dedicated line and we have 200 amp service. Oh and they also don't need to build the pad because I already have one out there. lol..

AC_hacker - Interesting bell curve distribution there. Yeah fossil fuel thinking is bad for heat pump sizing. The guy told me they design the system for a 95 degree day being cooled to 70 degree's. I said wait a minute, we would be perfectly happy cooling it to 85 degree's because right now we have no air conditioners. The house is so old and it has so many windows that the air flows right through the house. It's actually not that bad except for maybe a week or 2 in the summer.

The indoor air handling unit is going to be located in a 11x17 ft room, with 2 more larger rooms connected to it by open door ways. My heat loss is fairly bad, it's an 1890 house with single pane windows that I cover with bubble wrap in the winter. ( Aside, the bubble wrap helped incredibly )

I've looked at average temperature maps for Philadelphia. In Jan it's 25 degree's. That seems fairly decent to me. So I should design around that temperature is what you're saying right?

[Xringer]

No permits? Maybe, but in most places,
you can't hang a 230 disconnect box on an outside wall of your house,
without an electrician.. And he has to pull a permit.

When I say over-size, I don't mean over-kill. If you are thinking a 12k
might be good enough for 30-50% of your home, then stepping it up
to 18k isn't a massive jump.

When I looked at the price & watts per BTU of the difference Sanyos,
it seemed like there were a couple in my sweet-spot range.
The 24k seemed to be the best. After about 2 years, I think it was a good pick.
Since midnight last night, we have used 5.5 kwh. ($1.15 during the last 15 hours).
That's turning off at setpoint, but the average is equal to 366.66 watts continuously.

12:00>15:00___Current:___High:____Low:____Average:
Temperature:___53.6 °F___54.2 °F____33.7 °F___42.4 °F
(With some nice solar gain).

We have had the den open all day (not as much solar there), so we are
pretty much heating the whole house.

We don't need that 140,000 BTU oil burner providing heat 98% of the time,
and I know it would have cost us a lot more than $1.15 to stay warm
during the last 15 hours, if we were just burning oil..

We do AC more in the summer now, so that might delay the Sanyo from
paying for itself in under 2 years..

(We got the tax break too).

Cheers,
Rich