答复

1. Expert Member
   达娜·多塞特（Dana Dorsett）|2018年10月30日上午11:48|＃1

   是的，这很疯狂。多么疯狂？

   The heat load of reasonably tight 4000' insulated 2x4 framed house with clear glass storms and R20 fluff in the attic will come in about 80,000 BTU/hr @ 0F even without foundation insulation, about 60,000 BTU/hr with basement wall insulation. With no wall insulation and a lot of air leakage it may come in at or above 100,000 BTU/hr, but if it's that bad it's very cost effective to start fixing the building envelope. But even a 4000' tent doesn't have a heat load of 350,000 BTU/hr without leaving some windows or doors open.

   So let's say it's a fairly leaky sucker with almost no insulation and has a heat load of 100,000 BTU/hr at 70F indoors / 0F outdoors. A boiler with 300,000 BTU/hr would be able to heat the place at an outdoor temp of -140F.

   Are we expecting hell to freeze over or something?

   或者is it the idea that everybody sleeps with the windows open on the coldest night of the year?

   There's a double digit efficiency hit for a cast iron boiler for being 5x oversized for the heat load, even if there's enough radiation to emit 100% of the boiler's output on every zone. Even at 3x oversizing it's about a 10% hit. (See Table 3, and compare the steady state efficiency column to the 3x oversize factor column:https://www.bnl.gov/isd/documents/41399.pdf) If it's broken up into multiple zones the number of burn cycles soars and corresponding efficiency hit becomes even worse.

   This is why ASHRAE recommends an oversize factor of no more than 1.4x from the 99th percentile temperature heat load when specifying non-modulating heating equipment.

   通过调制冷凝锅炉，其中一些可以放松，但调制范围并非无限，而且大量过大的范围仍然可以以多种方式咬伤。在冷凝温度下，辐射输出速率较低，超大的尺寸会导致将锅炉缩短为较低效率（较短的生命周期）的风险。一些餐巾数学可以在这里生活：

   //m.etiketa4.com/article/sizing-a-modulating-condensing-boiler

   Since you don't have a heating history to compare fuel-use against heating degree-day data you can't put a stake in the ground on boiler output requirements, HIRE a third party such as a RESNET rater or professional engineer (and NOT an HVAC contractor) to run an Manual-J heat load calculation using aggressive assumptions (per the Manual) on things like R-values & air tightness.

   要在购买专业人士时进行理智检查，请尝试一些在线手册J工具，例如coolcalc.com或loadcalc.net。这些通常会以两位数的百分比来超大现实，但不能以三位数为单位。如果使用这些工具对铸铁锅炉进行尺寸，则不要超过1.2倍（如果可能的话）。

   As part of the analysis for the heating system run a zone-by-zone tally of the radiation. If much of the radiation is cast iron, use this as a guide:

   http://www.columbiaheatingsupply.com/page_images/sizing%20cast%20riman%20radiator%20Heating%20Capacity%20Capacity%20Guide.pdf

1. 
   slateandall|Oct 30, 2018 03:47pm|＃7

   I tried those two websites for Manual-J—way above my technical ability. The Columbia Heating document is very interesting. I will calculate EDR for the house. That seems like a fun doable project. How do I know if I have gravity hot water or a pump?

   哦，只有一个区域，但是某些房间里的​​散热器几乎没有加热。

1. Expert Member
   达娜·多塞特（Dana Dorsett）|Oct 30, 2018 05:04pm|＃8

   > How do I know if I have gravity hot water or a pump?

   重力热水系统的管道非常大，通常直径为4-6英寸。如果系统具有泵，通常很明显。它看起来可能是这样的：

   https://i1.wp.com/highperformancehvac.com/wp-content/uploads/2012/01/old_bell_gosset_circulator_pump.jpg?fit=363%2C272&ssl=1

   Is it possible that your system is steam?

1. 
   slateandall|2018年10月30日下午07:00|＃9

   我发现了一个流控制阀和一个泵。还有一个扩展箱。压力表似乎是一个常数。

   Yes, two of the original cast iron pipes are 4”. They connect together to a single smaller new copper pipe that goes into the FCV/pump.

   There are 4 other cast iron pipes (smaller than 4”) that connect to a single newer copper pipe that goes to the boiler.

   我认为这是从重力转换为泵的吗？2个厚的铸铁管提供了散热器，而4个较小的铸铁管是回报吗？

1. Expert Member
   达娜·多塞特（Dana Dorsett）|2018年10月31日上午11:39|＃10

   听起来很像转换的重力系统。系统水中的大量热质量意味着它永远不会短期循环，但是总体大小仍然不是您的朋友。

   我办公室里的一个人生活在约5000平方英尺的19世纪古董房屋中，曾经有类似的重力饲料锅炉后来转换为抽水。大约十年前，它被一个（现在不可用的）自由瓦特系统取代，该系统的共同发电机已嫁给了（仍在加热负荷的A（仍超大））190,000 BTU/HR（输出）调节冷凝锅炉和间接热水器。燃料使用实际上下降了一半，就他而言，Cogenerator在一年中大约4-5个月跑了24/7，也从电力账单上淘汰了一大笔钱。

   At some point it's going to be worth getting rid of the beastie boiler and going with a modulating condensing boiler that's appropriately sized for the heating load. With an ancient converted gravity feed the standby and distribution losses are huge, but a fuel-use based load calculation would put a very firm upper bound on the actual heat load (probably still a way oversized number). See:

   //m.etiketa4.com/blogs/dept/guest-blogs/out of-new-new

   开始节省您的汽油账单以跟踪这一点。

   In addition to the fuel use load calculation it will be worth paying a third party who it NOT an HVAC contractor to run an aggressive Manual-J heat load calculation on the place. If there are any insulating/air-sealing/window upgrades planned, the Manual-J should be for the "after upgrades" condition of the house. In my area a proper Manual-J performed by a certified professional engineer or RESNET rater runs $500-1000, but getting this right will save you more than the fee on upfront system costs and efficiency down the road. I can't count how many times I've seen systems proposed by HVAC contractors that are still more than 2x oversized for the actual loads. Modulation ranges aren't infinite- right sizing the boiler is still important even on high mass single zone systems.

   Some pictures of the boiler & plumbing might provide other insights.

2. 
   Jon R|Oct 30, 2018 01:15pm|＃2

   考虑添加一个水箱以减少短循环/效率损失。

   I'd improve insulation and air sealing now and then collect some data.

1. Expert Member
   达娜·多塞特（Dana Dorsett）|Oct 30, 2018 01:43pm|＃4

   >考虑添加一个水箱以减少短循环/效率损失。

   使用高质量辐射器，它可能不会是短循环的 - 除非它实际上是短的骑自行车，否则可以通过观察锅炉的行为，记录燃烧时间的长度以及每天燃烧的数量来确定。如果燃烧总是10分钟或更长时间，则不会进一步归因于短骑自行车。如果他们〜5分钟，可能会受到1％的命中，但随着燃烧时间的进一步减少，它会迅速增长。

   改造热清除锅炉控制拉back some of the efficiency lost to oversizing by reducing the average standby & distribution temperatures. System #3 in Table 3 of the Brookhaven National Lab took only a ~1% hit at 3x oversizing, primarily due to the heat purging control:

   https://www.bnl.gov/isd/documents/41399.pdf

   A heat purging boiler control also lengthens the burn times but reduces the total accumulated burn time per day/year, and reduces the number of burn cycles.

3. 
   slateandall|Oct 30, 2018 01:36pm|＃3

   谢谢！我将接受您的建议并收集数据并聘请独立专业人士，并研究水箱。

   到目前为止，我唯一的数据是与巢恒温器相关的。例如，一个早晨，当加热器49F时，加热器持续了2个小时，将温度从63F提高到70F（可能会稍微超出）。剩下的一天，每次跑了两次30分钟，将温度保持在70F。那天的高点是58f。

   During those three hours of use I think something line 8 therms were consumed.

1. Expert Member
   达娜·多塞特（Dana Dorsett）|2018年10月30日下午01:49|＃5

   >到目前为止，我唯一拥有的数据是与巢恒温器相关的。

   A call for heat from the Nest isn't exactly the same as the burner actually running. The Nest only calls for heat from the boiler- it doesn't control the burner directly. During a 2 hour call for heat the burner may have been cycling on/off as the boiler.

   温度恢复速率比燃烧器尺寸更大的辐射大小的函数。一百万-BTU/HR锅炉将热量放入辐射中，只能发射50,000 BTU/HR的速度不会比锅炉更快地加热该位置。

   多少区域，每个区域多少辐射？

   有邮政编码？

4. 
   删除|Oct 30, 2018 03:41pm|＃6

   删除