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SWEI

SWEI

Joined on November 26, 2011

Last Post on August 28, 2014

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No disrespect here, but

@ July 1, 2014 5:38 PM in New gas boiler sizing

"your local supply house" may not have a clue about proper training and installation practices of their customers.  A few do, but the majority in my experience do not.  A "local boiler guy" won't cut it either.

RPA members generally have a clue -- I'd start there.  The ones they have actually trained know their stuff for sure.

The rep firms are better, especially for certain brands.  Viessmann and Triangle Tube come to mind as having well-rounded installer training programs.  Lochinvar makes a great product, but I have no direct experience with their training programs.

Sensor locations

@ July 1, 2014 9:43 AM in TT Smart 80 & Prestige Solo 110 Summer Gas Usage

are significant, as you have just witnessed firsthand.  Now that it's picking up an earlier signal, you might try increasing the differential a bit.

Efficiency

@ June 30, 2014 6:36 PM in Converting Oil to Gas

Somehow thought you had a steam system -- apologies.  For hot water heating, a new boiler will indeed be much more efficient.

A properly sized, installed, and commissioned modulating condensing boiler will save more fuel than the AFUE numbers would indicate.  If you convert your historical oil usage into Therms, you should save at least 30% in fuel BTUs with a new boiler.

Conversion burners

@ June 30, 2014 5:51 PM in Converting Oil to Gas

} She explained that I won't get the improved efficiency of a gas boiler vs. an oil boiler

Quite the opposite, with a properly sized and installed conversion burner.

Not sure if Charlie travels that far, but perhaps Tim knows a tech nearby who can handle the work.

Cause and effect

@ June 30, 2014 10:45 AM in TT Smart 80 & Prestige Solo 110 Summer Gas Usage

are inexorably intertwined here, and not really the point.

Let's assume for your particular location, weather, and fuel that condensation begins at one very specific temperature -- say 130ºF.  The efficiency difference between return temps of 129ºF (we'll call that condensing mode) and 131ºF (we'll call that non-condensing mode) would be almost immeasurable.  The curve is smooth and has a low slope.

ecocirc e3 Vario

@ June 29, 2014 6:33 PM in ECM circulators

Has a knob on the side -- just turn it to the speed you want (we dial in the ∆T we want) and leave it there.

Condensing mode

@ June 29, 2014 6:28 PM in TT Smart 80 & Prestige Solo 110 Summer Gas Usage

is actually a misnomer.  As the boiler water return temp drops, efficiency goes up.  As efficiency goes up, condensation increases.  Cold DHW lowers boiler return water temps significantly.

One GPM

@ June 29, 2014 1:29 PM in ECM circulators

is clearly in the ecocirc e3 realm.  They're no less expensive than an Alpha or a Stratos, but they draw tiny amounts of power.  Much better to run a pump in the sweet spot of its curve than to bounce of the bottom.

Curious about the plate radiator

@ June 29, 2014 1:17 PM in recent job

looks like a Myson -- mounted under the other radiator.  Is that fed with steam, or catching condensate on the way down?

Indirect calls

@ June 29, 2014 12:54 PM in Water Tank Temperature After Shower

on all the mod/cons I have used force the boiler to a preset water temp, then shut off once the DHW hits the preset temp.  The smarter ones use a thermistor in the tank to increase response to a droop and reduce overshoot.  With external controls we can take them to the next level -- firing the boiler to the lowest temp which will achieve the needed recovery.  Combine that with some intelligent setpoint management and we see far fewer ignitions.

Sensible and latent loads

@ June 28, 2014 10:48 AM in Cooling load, heating load, sizing equipment

are calculated separately.  I'm not sure where the "80% to 90%" numbers came from, but maybe that works in Chicago.  There is more than one way to remove humidity.  I'm sure Rich's guy is familiar with all this.

The complete lack of cluefulness demonstrated on your heating load makes me question the whole deal.

SMART indirect temperature sensors

@ June 28, 2014 10:33 AM in Water Tank Temperature After Shower

Are located roughly in the middle of the tank, or at least the bottom of the sensor well is.

It sounds as though your contractor did replace the tank aquastat with the 12k thermistor (that's how the boiler sees the tank temp you presumably read from the boiler display.)

Floor zone

@ June 26, 2014 10:06 AM in need electrical help

is this by any chance a radiant floor?  Why did you select the BWF?

Did anyone do a heat loss calc for this job?

We call it an apron

@ June 25, 2014 2:04 PM in Thermal break at overhead doors

and you just described nicely what I was trying to convey.  Separate the part of the slab that is under (and just outside) the door from the main interior portion.  Heat it or not -- your choice -- but keep it isolated at least a bit.

Personally, I'd run it at least 18" past the door and set it up for a separate snowmelt zone as ice described in his original reply.  It's really, really nice not to have to chip away at the door closure after a cold night.

Can you tie the apron to the main slab

@ June 25, 2014 12:18 PM in Thermal break at overhead doors

with a bunch of #7 bar that bridges the thermal break?  Heat transfer is all about area, and that might do the trick.

Codes vary

@ June 24, 2014 10:22 PM in Main Lobby in hotels

depending on jurisdiction.  Here in the US, we have an assumed occupant load of 15 square feet per person for lobbies.

Fermentation

@ June 24, 2014 5:53 PM in The history of the toilet

is quite sensitive to foreign critters.  The neat thing about beer and wine is that almost anything undesirable that grows alters both smell and taste in an obvious way.  So if it smells OK and tastes OK, it usually is OK.

Energy Costs

@ June 23, 2014 10:36 PM in Need help rating these radiators.

Every year, a larger portion of our domestic electricity is produced from natural gas.  When the power company burns gas, it only converts 50-60% of the available BTUs into electricity.  An additional 20-25% is lost in distribution.  Net net is that you are lucky to see 40% of the BTUs that are burned delivered to your premises.

A properly functioning commercial steam boiler will convert about 85% of those BTUs into heat.

Don't be lulled into complacency by the power company PR.

For this size and complexity of project

@ June 23, 2014 10:22 PM in Need help rating these radiators.

You really do need some professional expertise.  The sizing of A/C versus heating loads is one area, as mentioned above.  Occupancy patterns make a significant impact.  If the sanctuary is used once per week, mostly uninsulated, and constitutes the bulk of the total facility load (quite common in older churches) that skews things significantly, and in a manner which standard equipment sizing programs will not account for.  Air distribution in high-ceiling rooms is in itself an art form, and one which the Asian split makers have not generally addressed.  There are ways to do it (by pairing their short-duct evaporators with special nozzles) but it's not common knowledge amongst the installer base.

We are trying to help you be careful with your congregants' money.

You're in luck!

@ June 23, 2014 6:38 PM in Need help rating these radiators.

Dave works in your area and will not steer you wrong.

For an intermittently-occupied minimally insulated building (like a sanctuary) nothing can touch steam for quick recovery.  You really can have the best of all worlds with a properly designed (and controlled) hybrid system.

Properly implemented geo-exchange is a beautiful thing, but modern inverter-driven air source heat pumps often represent a better bargain (unless you happen have a large body of water or free-flowing stream on site.)

Who's designing the geothermal system?

@ June 23, 2014 6:04 PM in Need help rating these radiators.

there is sophisticated software for this, sometimes even free from the manufacturers.  Sizing of coils is critical and depends on heat loss/gain as well as latent (dehumidification) loads.

The ratings depend on temperature

@ June 23, 2014 12:55 PM in Need help rating these radiators.

Unless there have been some envelope upgrades, it's quite likely you will not be able to heat the building on a design day with a heat pump and the existing radiation.

http://usboiler.net/library/USBoilerReport/heatinghelper/offline/download.pdf has a lot of useful info.  Note in particular the derating of EDR for temperature on p. 37 and remember that the vast majority of heat pumps can't supply water hotter than about 130ºF.
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