Heating Help

There's your problem, Scott

@ January 29, 2006 10:53 PM in Air to Air wrecking a radiant system

The radiant guy must have had a system that couldn't keep up with the fresh air exchange in the bathrooms, since they were seeing up to 100cfm continuous. I guessing now, but the perceived stratification might have been chilly air at ankle level. You shouldn't have any problems especially if the HRV is on a timer.

storing heat in the basement slab

@ January 29, 2006 4:35 PM in first stab at heating model

I should have added that if you use this approach, the boiler needs to stay off during the constant circulation mode during the sunny day. In a typical passive solar layout, though, it's reasonable to assume that it will naturally stay off once the sun starts pouring in.

My house is set up similarly

@ January 27, 2006 1:30 AM in first stab at heating model

I'd say save your money on the fan coils. Even if you were feeding the fan coil 75F water, the air will feel cool blowing around. And it's very unlikely that a day's worth of solar gain will even get that 6" slab up to 75F. You need temperature differences to move heat around efficiently, and your delta T's are quite small. However, an approach that is definitely worth trying is simply to provide continous circulation to the entire house and basement from 10am to about 8pm (depends on solar gain and outdoor temp). (Forgive all the following if you've already tried this) Under this scenario, warmth from the passively heated rooms/floors will automatically migrate to the basement slab. The Warmboard acts like an active solar collector, and the basement slab acts like the storage tank. After the sun goes down the heat automatically migrates from the slab to the rest of the house. Another way to look at it is constant circulation is keeping the whole house at a more constant, comfortable average temperature. Again, the delta T's may not be enough to drive the heat around sufficiently to even make this theoretical improvement noticeable. Therefore, don't spend too much time or money on the control strategy. I never got around to implementing this on my house because I really don't have any overheating upstairs even on the sunniest winter days. This is mainly due to the 2" concrete floors upstairs. Putting the thermal mass right where I need it was helpful in my case.

Craigslist.org

@ January 27, 2006 12:36 AM in Plumbin / Heating Materials

easier selling than ebay, but there are lots of ebay resellers out there that help out for 30%.

An HRV wouldn't cause stratification

@ January 27, 2006 12:26 AM in Air to Air wrecking a radiant system

Air movement of any kind and the introduction of fresh air into the house theoretically helps mix the air and reduce any temperature stratification. This radiant guy must have had some problem in the past that he still believes was caused by the HRV. Find out about that issue and see if it applies to this job or the homeowner will be really unimpressed with the finger pointing that is starting during installation. Now, there is a school of thought that says you still need decent bath fans (eg. Broan HRV installation literature)as well as the HRV. The theory is you get the smell and humidity out quickly.

Run the hot water to the shower thru it

@ December 29, 2005 7:40 PM in Where to get a small circ.

The perfect control. Not too good for bathers though.

Ventilorad

@ December 26, 2005 2:20 PM in I wonder how this product would sell today (Dan H.)

Ventilorad is not a very catchy name. Neither is Supplemental Baseboard Airflow Fan. I ran a few ads in Solar Today, got hundreds of inquiries but not one order. They worked well in my solar baseboard retrofit systems, but they eliminate the perfect silence of hydronic baseboard. Thankfully, my development cost was just a month of my own time for the tooling.

Instant fan coil

@ December 24, 2005 2:12 AM in I wonder how this product would sell today (Dan H.)

Here's a similar product I manufactured and marketed in 1983. It also failed because of a bad name.

Insulate all near boiler piping?

@ December 23, 2005 5:10 AM in Insulation

Do you go right up to the boiler in all cases? I have a 23 unit apartment building with a steam boiler.

Elbows and Tees

@ December 23, 2005 5:04 AM in Fiberglass vs foam insulation for basement steam pipes?

The pipe insulation one sees on old steam systems has a really great looking (and obviously durable) covering. I assume it is something like asbestos impregnated plaster of Paris. Is there a updated version of this still available? (Anyone who's broken a bone knows how to apply the stuff) I've actually used those plaster of Paris rolls from Hobby Lobby, but that's paying small-quantity-retail and it adds up quick. Is latex paint the best finish coat?

More info on the subject

@ December 1, 2005 2:29 AM in Define... (ME)

Here's a paper on Germany's "Deep Probe" solar/geothermal system: http://www.energyprobe.org/energyprobe/reports/ErHiLiRaSc98.pdf Love that name

FWD trivia

@ November 30, 2005 12:02 AM in Constantin -

Those beautiful, big GMC motorhomes from the early 70's used the Olds Toronado fwd drivetrain. You can have problems on steep hills because of the weight shift to the rear.

Nope

@ November 29, 2005 6:37 PM in thermostat setback

Steve, "with 10:30 pm setback to 6am I use much more to recover than I save in 5 hours of setback." If this is really true, it must mean that the boiler efficiency is significantly lower during the morning recovery. Possible I guess, but not likely. Definitely not half as efficient as you stated: "My gas consumption was twice roughly last year's October for a milder month."

@ November 28, 2005 10:46 PM in informal pole

and lunchtime apparently

Biomass is also CO2 neutral

@ November 28, 2005 10:43 PM in Define... (ME)

They use up the same amount of CO2 when being created as they release when burned. I guess particulates are the biggest problem.

@ November 28, 2005 2:12 PM in Constantin -

Is the Sprinter front wheel drive?

Ground couple the tank

@ November 27, 2005 1:21 AM in Define... (ME)

Mark, As Jerry Scharf says just above, you theoretically run out of heat in the big tank when you take it down to 40 degrees. The solution to that is to leave out the tank insulation in spots where it's thermally connected to the earth. The the 55F earth gives up heat to the 40F tank, and you still have heat for the house. The ground-coupled surface area of this tank is nearly equal to a typical slinky loop, so yeah, I think this would work great. Now the question is if it saves enough money vs. GFA/AC to justify the extra cost.

Ron Larson's solar array

@ November 27, 2005 1:01 AM in Define... (ME)

Ron has roughly 100ft2 of Thermomax e-tubes. It's just two people in the house, so about half the day's solar collection goes to an 80 gallon solar DHW tank. Once that tank is up to 170F, then the rest of the solar goes into the large tank. So in essence, 50ft2 of collector has stored the 7.5mmbtu in 1/2 year. He plans on being up to 140-160F by the end of next summer. (sheesh) Please note that Ron's big tank wasn't intended to support a heat pump, nor was it designed as conventional seasonal storage. It's just his way of eliminating the fossil fuel boiler and the associated installation labor.

New source of complaints

@ November 26, 2005 1:08 PM in Define... (ME)

Joel, Have you had this problem yet? You have this client interested in efficiency, so he builds a very tight house. You install a Viessman system with radiant floors. (Could be $20-$40k right?) Since he's kind of a tree hugger, he sets his thermostat to 65 degrees. Now he calls to complain because the boiler never comes on and his floors are always cold.

minimize heat loss first

@ November 26, 2005 10:44 AM in Define... (ME)

Joel, You're absolutely right, but the subject could be a little touchy here at the wall. With a superinsulated house and a little passive solar gain, then the best system for the money isn't a $20,000 ground coupled heat pump system with hydronic radiant floor. It makes more sense to install just a few electric resistance heaters for $2000. Why spend $18,000 to save $400 a year? (just grabbing rough costs out of the air, YMMV)

solar augmented ground coupled heat pump

@ November 26, 2005 4:43 AM in Define... (ME)

Mark, You should show how and where DHW ties in, because that load is what justifies the solar panels. Once that is in place, I really think this is the system for the immediate future. A simplification I'd suggest: Just run the Pex in a 4" conventional basement slab. Cover the slab with 2-3" of EPS, then laminate flooring. No insulation under the slab. Now you've got plenty of ground-coupled surface area without any extra digging. Now it sounds a lot like something we discussed last year: http://forums.invision.net/Index.cfm?CFApp=2&Message_ID=44229 Also don't worry about eliminating the ability to heat the basement radiantly. A truly well insulated basement is heated by the people and the lighting.

This has been done near Denver

@ November 26, 2005 3:48 AM in Define... (ME)

Jerry, I've checked the back of your envelope, and you're in the right ballpark. Last year I did a very similar calculation in another thread. http://forums.invision.net/Index.cfm?CFApp=2&Message_ID=123850 My main point at the time was that active collectors with a large storage tank may well eliminate the need for a fossil fuel boiler in a well-designed passive solar house in Colorado. (BTW, Ron Larson's 12,000 gallon tank went from 40F to 116F from April 05 to Oct 05.) Also in that thread, Dale Pickard went on to explain your same conclusion that seasonal storage is impractical. Mark Eatherton is showing a heat pump in his drawing just as you concluded would be best. When it runs out of solar heat, the heat pump sucks the balance of what it needs from the ground.