A7 AirTap install (ASHP hot water heater)

[randen]

I just had a thought while you guys where talking about the price of oil and how much you where going to sell your left-over oil in a couple years. In my research to justify the installation of my homes GSHP, the cost of furnace oil in my area more than doubled in six years. Thats a better return than most stocks. Maybe a good investment is the 1000gal tank we have here can be filled and in a few years it can be sold and put my son thru college!! just a thought.

Randen

[Hv23t]

Originally Posted by Xringer

at this rate I have enough propane for 25 years.

LOL! That's kinda like our heating oil tank. It could last 25 years too.
Not sure that I'll be around to see it. But, if gasoline goes up to $35 a gallon,
diesel will be about the same. And, this #2 fuel oil works in diesel cars..

I wish Propane was cheaper, it would be good to be able to cook with it, in the kitchen.

My kid really burns up the propane. She cooks on her grill about 5 times a week.

I got her a Weber Q300 a while back and she liked it so much,
I got one for my wife too.

Nothing like cooking on a gas grill..

Propane is a excellent fuel just too pricey. Last time I bought which has been a while it was 3.85/gallon. I'm sure it has gone up since then. Thing that is getting on my nerves is that I pay a $60 tank rental each year and I'm probably only using $20 worth of propane a year.
My wife works for a company that owns a bunch of pizza resteraunts. One store they own is up in the mountains where they don't have natural gas, so the store has its own propane tank. I saw the bill for the store when I stopped by her office and they only paid 1.19/gallon. If I could get it that cheap I'd convert all my cars over to it. And it's the same company that we used here just a different branch.
Anyways I've started my own ashp water heater project. A buddy gave me his old 40 gallon GE electric water heater and a dehumidifier. I already made ports to run the copper refridgerant lines into the tank and I've started taking the dehumidifier apart. I've ordered 25' of copper tubing I'll use for the hx. So as soon as it comes in I'll braze it up throw in some of my 25 years worth of propane and see how it works.

Hv23t

[kbonk]

HI X, can I ask how much you sprung for the A7 ? would you do it again or hack one? I found one for 600 delivered
regards K

[berniebenz]

Originally Posted by kbonk

HI X, can I ask how much you sprung for the A7 ? would you do it again or hack one? I found one for 600 delivered
regards K

The last one sold on eBay went for $153. +50 shipping. Nothing since.

[Xringer]

Mine was $437.00 (Free shipping) from Ebay. I should have ordered a back-up unit.

$600 is under the Lowes price..
Shop AirTap 50-Gallon 6-Year Table Top Electric Water Heater at Lowes.com

The A7 isn't UL listed and there is a chance of R22 leaking into the tank.
No double-wall HX might be illegal in your area.

Ours is working fine so far. It makes enough hot water for us (2 old folks).
My wife loves having faster & warmer hot water.

Not sure that I would want to build a DIY ASHP water-heater.
Now that I know a little about the A7, I would most likely spend $600 if this one got totaled.

$600 isn't exactly cheap, but you can't take it with you.
With food and gas prices nowadays, you can't even take it into next year..

[Xringer]

It's been averaging 55F in the basement for the last week. (Not including today)
The A7 power use ave is 0.93 kWh per day. (15 cents).

Seems to be about the same as the last time I checked it..

Here's the outdoor temperatures for the week..




~~~

Random Run Times:

Sometimes late at night, I hear the A7 running. I look at the clock, it's 10 or 11 PM, or even 2 or 3AM,
and I'm not going to need any hot water until after 8AM the next day.

That water tank might be nice and hot by midnight and then sit there slowly cooling off all night long,
before anyone wakes up enough to spin the 'H' tap..

So, I'm wondering about using a timer that keeps the A7 off, between 10PM & 6AM..

I know the first run of the day might be right at 6AM, and it might be longer than normal, but is that a bad thing?
It seems like less on-off cycles might extend the life of the unit..?.

I'm not sure what the impact on the power use would be. If any.

What do you guys think of the timer idea?

Comments please:

[berniebenz]

As I recall, you just installed your A7 on a new GE electric HWH. Thus, must be a well insulated unit. Are you not trying to guild the lilly? Fat wallet syndrome bugging you?

[Xringer]

I think it's just a little 'on-demand' idea sneaking in.
But, mostly it's the new noise in the house.
I'll be up at 3AM and walk into the kitchen for a drink of water or a snack,
and I'll hear the A7 come on, and think, why did that come on? no one used any hot water.
Makes me want to go down and look at the temperature displays..

There is a small amount of heat loss. I'm sure the long copper HX loop hanging
down in the water is going to conduct some heat up into the guts of the A7,
allowing a little bit of heat to radiate off the large HX..

It's output air vent is on the top (front), and I've been thinking about adding a small flap over the vent.
I would use a piece of coroplas with a tape hinge. Air pressure would lift it up when the unit was running.
Sort of an anti-air-convection loss valve. It might slow the loss a tad..?.

Anyways, I have the timer and I'm curious how the A7 would work, with a 5 or 6 hour pwr-off window.
May as well try it. Can't break anything.

[Xringer]

I tested the anti-air-convection loss valve using some coroplas and duct tape.
It flopped. The coroplas is a tad too heavy, or the fan isn't blowing much air out the exhaust.. (It's too weak).

The A7 is still working well in a very chilly basement (55F today) and the timer
experiment is working. Twice this week I was up at 6AM (been working lately)
and heard the compressor running.

I like that it's not running in the middle of the night, when no one wants to use hot water..

[Hv23t]

Originally Posted by Xringer

It's been averaging 55F in the basement for the last week. (Not including today)
The A7 power use ave is 0.93 kWh per day. (15 cents).

Is the A7 doing all the heating of your water, or are you still using your boiler as well? That is an amazingly low energy usage. How many watts does it use while running?

Hv23t