EPA wood furnace - Caddy

[Eric Johnson]

That's great news! Was there any public announcement about this plan? How do you know about it? If I buy the Caddy today, will I be able to add the coil later?

Eric, how much did you pay for the EKO and how much for the tank? I am concerned also with the complex plumbing that heating with water requires. Water is corrosive + sediments of minerals ...

You can get the current pricing for the EKO line at http://www.cozyheat.net. I'm only providing that link because it's the only place I know of that posts the prices. There are other dealers selling EKOs around the country.

I cobbled my tank up from an old concrete cistern in my basement. And I'm about finished building my heat exchanger, which is made of rigid copper. If you bought them retail, a 1,000 gallon tank and heat exchanger would probably set you back around $5,000. Maybe more. I have a lot of hours, but only about $1,000 in mine.

And yes, getting everything piped up involves extra expense and time.

 

[Stove Geek]

For the Caddy XL, it will meet the Canadian EPA standard, because it has a clause for large furnaces. The way the US EPA method is setup, it makes it impossible for very large fireboxes to pass EPA. The US method has a calculation for burn time that would require the Caddy XL to burn one load of wood for over 20 hours...without a single trace of smoke...we all know that's impossible. But I can tell you it will have very low emissions, no smoke. It will require a hot water tank for storage, no option there....for the specs, the draft will be available to the public in the summer of 2008. It will be th very best furnace produced by PSG to date.

 

[Beno]

Stove Geek, I feel so lucky I am able to get this info. Thanks!
The Caddy has a firebox of about 3.5 cu.ft. What will be the firebox cu.ft. of the newer Caddy XL?
Caddy did pass the US EPA tests, correct?

I might not be able to wait for the Caddy XL, we will build in spring - summer, and also we may not have the room for a large water tank (we have no basement because of high water table). I am sure though that other people will find this info very valuable.

Stove Geek and Eric, if I go with Caddy wood/oil furnace, what will be a smart solution for DHW?

 

[Stove Geek]

The Caddy did pass US EPA - the first in the world!

For the hot water, go tankless...that is the most efficient way - to my opinion.

 

[Eric Johnson]

If you can put a coil in the furnace, then you would be ahead, in my opinion, to circulate water between the coil and a conventional water heater. You'll have free hot water. But I would only do that with a coil designed for that furnace and preferably factory installed. It can be dangerous if not set up right.

 

[Beno]

This will probably make me loose the warranty on Caddy, and maybe even house insurance problems. What do you think about Eric's idea, Stove Geek?

 

[Stove Geek]

To keep your warranty, you should put your water coil over top the furnace, inside the warm air plenum...keep it outside the furnace cabinet...

 

[micah]

I have a concern about the one with the oil backup. I have been told NEVER to vent 2 things in the same flue. So does this require a second flue, one for each? Or is it that you cant RUN 2 things at the same time that are vented through the same flue?

 

[Beno]

They don't run at the same time.

 

[Eric Johnson]

The only time you are allowed to vent two different appliances into the same flue is if they are a combined unit. In some cases, you have no other choice, since both sides sometimes use the same exhaust outlet. It's not the smartest thing you can do, but it's within code. You can even run them at the same time. When it comes to two separate appliances, however, you are correct.

 

[Stove Geek]

The code says to run one appliance per chimney - The Caddy is one appliance that is approved as a combination furnace...it works great.

 

[micah]

[DELETED] You guys post to fast.

 

[Eric Johnson]

No. Like I said, separate appliances require a separate flue. You might get away with venting a gas hot water heater into the same flue as a gas boiler or furnace. That's how mine was hooked up before I switched to electric HW.

 

[micah]

Thats how mine is to Water heater and furnace use the same flue. Ill be switching to electric water in the spring.

 

[Beno]

Stove Geek, can I use the same flue used by Caddy wood/oil also for an oil hot water heater? The oil hot water heater can go with either direct vent or a flue. If possible I'd use one flue for the Caddy and the oil hot water heater.

 

[Stove Geek]

For new installs, it is one appliance per flue...so the hot water tank cannot be vented in the same flue as the Caddy...

 

[BrownianHeatingTech]

Okay, two things...

A lot of this is determined by code, and not all locations use the same code, so caveat emptor, and check with your local code enforcement. Do not ask them if you can do it. Many local code officers are helplessly ignorant (not all, or even most, but far too many). Ask, "can you get me a photocopy of the code that describes when multiple appliances can and cannot be vented in the same flue, so I have it for my records." That makes them actually look up the code, rather than just giving you whatever answer comes to mind first.

Second thing. Typical codes allow multiple appliances per flue, even on new construction, if they are oil or gas appliances. What they do not allow is solid-fuel and liquid/gas-fuel appliances to share a flue. They are separate critters, and shouldn't. The typical rule for oil/gas appliances is that they may not enter the same flue at the same height, unless they are pre-connected in the flue pipe, before it meets the chimney (in which case there are rules about how that is done).

Exceptions are made for combination appliances. But a separate oil-fired appliance cannot share a flue with a wood/oil combination unit.

The reasons are possible flue gas spillage (CO poisoning), and getting cinders into a oil or gas appliance. I replaced a boiler a while back, which shared a flue with a woodstove. The woodstove was on the first floor, and the boiler in the basement. The boiler was half-plugged with cinders from the woodstove.

Incidentally, the woodstove hadn't been run in three years, and they'd been paying for yearly boiler cleanings, which kind of proved that the company they'd been paying to clean the boiler had been slacking severely. And it was a separate tech each year, so it wasn't just one guy who was a slacker.

By the way, I'm not giving anyone legal advice here. As I said, check your local codes. Local codes can be more restrictive than state-level codes, and some are downright wacky. The above information is simply what I've dealt with most commonly, as best I can phrase it.

Joe

 

[Stove Geek]

We're on the same page...
The Combination furnaces are considered as being one appliance although have two fireboxes...

 

[mtnxtreme]

Im also building a new home in the spring, but with a lot of sweat equity, so heat won't be needed till spring 09 probably. I was first considering Tarm or AHS wood/oil unit, to be used with a hot water radiant floor system, they are priced rather high $6-8000. I see you guys talking abt. this Caddy unit for $2500, do they have a comparable unit to the Tarm or AHS. Whats the pros/cons. How long will it take me to see a return on my investment, I can buy a comparable sized oil only unit for like $1500. Looking for ideas.

 

[Gooserider]

Im also building a new home in the spring, but with a lot of sweat equity, so heat won't be needed till spring 09 probably. I was first considering Tarm or AHS wood/oil unit, to be used with a hot water radiant floor system, they are priced rather high $6-8000. I see you guys talking abt. this Caddy unit for $2500, do they have a comparable unit to the Tarm or AHS. Whats the pros/cons. How long will it take me to see a return on my investment, I can buy a comparable sized oil only unit for like $1500. Looking for ideas.

Could be wrong, but I believe the Caddy unit is a forced hot air furnace, while the Tarms, EKO, etc. are forced hot WATER boilers. So you are looking at totally different heating methods. In general, HVAC setups are less expensive, boilers much more expensive, but do a better job of heating / more comfortable / quieter / cleaner... Also boilers seem to last longer if properly taken care of.

Gooserider

 

[Eric Johnson]

Goose is right.

 

[BrownianHeatingTech]

Furnaces typically have 30-50% shorter lives than boilers (depending on the particular boiler and particular furnace, obviously). They also consume dramatically more electrical power, which can be a concern in terms of cost, or in terms of running on backup (batteries/solar/generator) power.

Joe

 

[Beno]

I think we need to compare here the systems and not the elements.
Around the boiler you have lots of plumbing, and things may break there. The air ducts will not make problems (if you keep changing filters on time). Also, with hydronic heating you need to supply ventilation (ERV/HRV, some smaller air ducts), and you don't have air conditioning in the summer. Also, it is recommended to have large/expensive water tanks for heat storage.
If you don't have a boiler, the DHW may be supplied with an oil heater and eventually solar.

 

[BrownianHeatingTech]

I think we need to compare here the systems and not the elements.
Around the boiler you have lots of plumbing, and things may break there. The air ducts will not make problems (if you keep changing filters on time). Also, with hydronic heating you need to supply ventilation (ERV/HRV, some smaller air ducts), and you don't have air conditioning in the summer. Also, it is recommended to have large/expensive water tanks for heat storage.
If you don't have a boiler, the DHW may be supplied with an oil heater and eventually solar.

If you would need ventilation with your hydronic system, you would need it with a forced-air system. The need for ventilation relates to the tightness of the structure, not the heat-delivery system.

Air ducts are a breeding ground for all manner of nasties. Open up an older air system, and you won't like what it looks like inside there. Not that it will necessarily be bad, but it can get there way too easily if the conditions are right.

You only need heat storage tanks with gasifiers. A "disadvantage," to be sure, but since the furnaces don't have the option of being gasifiers, let's compare conventional (non-gasification) wood boilers to the non-gasification furnaces...

The lack of air conditioning is about the only drawback, and that can be remedied with ductless mini-splits (Fujitsu happens to be my favorite), while using a lot less energy than most central A/C systems.

Joe

 

[Beno]

1. Based on the code in my area, I need ventilation to each room if I don't have a furnace with air ducts. If I have a furnace, the ventilation will be done by the furnace fan to the rooms, and I'll have to supply outside air to the furnace. So, even with hydronic heating I need to install ducts (smaller) for ventilation. Cleaning them may be harder than with the furnace ducts.

2. I thought that the wood boiler comparing in efficiency with a Caddy EPA wood furnace has to be a gasification boiler. Can you please recommend a very efficient (non-gasification) wood boiler?