Difference between revisions of "Hvac"

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====air to air====
====air to air====


===heat pumps===
# goto E://OneDrive/jupyter/energy
====HSPF====
HSPF is defined as the ratio of heat output (measured in BTUs) over the heating season to electricity used (measured in watt-hours).[1][2] It therefore has units of BTU/watt-hr.
 
The higher the HSPF rating of a unit, the more energy efficient it is. An electrical resistance heater, which is not considered efficient, has an HSPF of 3.41.[3]
 
Depending on the system, an HSPF ≥ 9 can be considered high efficiency and worthy of a US Energy Tax Credit.[4]
 
calculated over a year
HSPF = BTU/watt-hr
HSPF = BTU/(1000*kwh)
 
For instance, a system which delivers an HSPF of 7.7 will transfer 2.25 times as much heat as electricity consumed over a season.[5]
====oversizing is not OK====
from [https://www.energyvanguard.com/blog/can-you-oversize-a-mini-split-heat-pump/ Energy Vanguard - Allison Bailes]
 
Understanding turndown
For example, the Mitsubishi FS06 wall-mounted ductless unit has a rated cooling capacity of 6,000 BTU per hour and goes down to a minimum capacity of 1,700 BTU per hour.  That’s a turndown percentage of 28% (1,700 ÷ 6,000).  If you put that unit in a room with a load of 1,500 BTU per hour, it will bottom out nearly 100% of the time it’s running in cooling mode.
 
Sometimes you’ll see turndown ratio, which is the same concept as turndown percentage but upside down.  It’s the ratio of maximum to minimum capacity.  For the example here, it would be 6,000 ÷ 1,700 = 3.5.  So the turndown ratio is 3.5 to 1, sometimes written 3.5:1.
 
What happens at part-load?
One of the great advantages of using mini-splits is their variable capacity.  By oversizing them, you can lose that advantage completely.  That 6,000 BTU per hour mini-split in a room with 1,500 BTU per hour of cooling load doesn’t act at all like it has variable capacity because it’s always running at the lowest capacity except on the really extreme temperature days.
 
When the bottom end of the capacity range is at or above the heating or cooling load, there’s no benefit in part-load conditions.  As the heating or cooling load drops from the design load, you want a system whose capacity also drops.
 
That 6,000 BTU/hr system with a bottom end of 1,700 BTU/hr serving a load of 1,500 BTU/hr doesn’t vary at all in part-load conditions.
 
When the load is 1,500 BTU/hr (the design load), the system will give you 1,700 BTU/hr.  When the load drops to 1,000 BTU/hr, the system will give you 1,700 BTU/hr.  When the load is only 500 BTU/hr, the system will give you 1,700 BTU/hr.
 
Yes, oversizing is a problem
 
So, yes, you absolutely can oversize a mini-split.  And when you do, you end up with some of the same problems you get from oversizing conventional systems:  poor humidity control, short cycling, and wasted money.
 
====air to water heat pump AWHP====
[https://www.arcticheatpumps.com/specifications.html arctic specs suck]
letters to Arctic
 
My use for your '''air to water heat pump products''' will be limited to '''DHW''' and the '''existing kitchen/bath radiant loop'''. That might extend to some kind of wall '''radiant emitters''' for the other two bathrooms depending on calculating the load and the availability of products matching the load. My needs most closely match the following configuration.
 
<img src="https://cdn-fdbpa.nitrocdn.com/gKOxVeMEjzbIXyXQDzDOXkUdVDxCjtsJ/assets/images/optimized/rev-a08ae6a/www.arcticheatpumps.com/images/2022/01/26/h-w1.jpg" alt="Girl in a jacket" width="800">
 
I will set up some monitoring on the existing radiant loop for temperature-in and temperature-out which combined with knowing the flow rate should give me the btu/hr load.
 
I am not looking for a "quick estimate". What I need from you is performance and engineering data and pricing on all of listed components.
 
The rest of the house will likely replace 180 degree baseboard emitters with air to air heat pumps connected to some combination of wall units and air handlers.
 
29 years ago this was a carefully designed system  which heats a 2,700 sf house with high ceilings and lots of windows for ~$1,500/yr @ $2.33/therm. I even got John Siegenthaler to weigh in with some invaluable advice.
 
With electricity here @ $0.27/kwh and natural gas @ .07/kwh it will be a big challenge to design a replacement system. Whatever it is will have to spend most of its time in the operating range that gives you a COP of ~4 or else the operating cost penalty will be too great.
 
I am licensed builder in MA with EPA 608 universal lic. and am a member of the MassSave Heat Pump Installer Network. So far I have had very good results replacing oil steam boilers with cold climate heat pumps connected to air handlers delivering heat through exposed spiral ductwork running in the conditioned space. Tenants are spending almost half of what oil cost to run their systems.


===system design===
===system design===

Revision as of 13:13, 7 January 2024

now located at e://onedrive/jupyter/energy

old version

HVAC-Parley

products

air to water

THERMA V Monobloc air to water pdf in parley/energy/air2water 

r32 Monobloc
 5kw HM051MR U44
 7kw  HM071MR U44
operating rang for heating
 outdoor air:  (-25C)-13F - (35C)95F
 leaving water: (15C)59F - (65C)149F
LG launches Therma V R290 Monobloc propane AWHP
  • a new version of The Therma V R290 Monobloc heat pump
  • flow temp 75C (167F)
  • 100% output @ -15C (5F)
  • uses propane (R290)
  • LG is offering the heat pump in four versions with nominal capacities of 9 kW, 12 kW, 14 kW and 16 kW.
  • Its seasonal coefficient of performance (SCOP) is reportedly over 5.

Monobloc is all in one solution without additional indoor unit. It’s only connected to water tank so easy and simple to be installed. Contact us for this sustainable heat pump system. At low ambient temperatures down to -15℃ (5F), the Monobloc delivers powerful heating at 100% capacity

air to air

  1. goto E://OneDrive/jupyter/energy

system design

messafge to Artic

Currently I have a 27 year old radiant floor system for the kitchen (200sf) and bath (50sf). It is pex in a thin slab under ceramic tile over an insulated joist/plywood floor. It runs continuously in the heating season on a loop off of a gas boiler that injects a bit of 100 degree water whenever the boiler is calling for either a baseboard zone or DHW.

The boiler is about ready to be replaced and I am exploring the feasibility of a design for both DHW the radiant loop to be powered by a heat pump or heat pump hot water heater. What do you suggest?

maintenance/repair

11/5/21

problem: tstat lights were on but zone valve lights were off. End switch was not being activated for LR and TV (intermittent)

  • replaced LR zone valve with new, voltage between terminal 1 and 3 was low
  • replaced TV zone valve with clip salvage, voltage between terminal 1 and 3 was low
  • ordered spare from ebay. Still have one clip salvage 2nd shelf near boiler. Replaced valves are on top shelf, have tape folded back to indicate they were replaced.

https://mckwiki.parleyvale.com/images/f/f6/SelectingCirculators.pdf

heat pump

https://www.pmengineer.com/articles/92614-cold-climate-air-to-water-heat-pumpspart-2

pme0716Siggy_Figure4.png


email to Artic on air source hydronic

I am interested in Arctic Heat Pump 035ZA/BE – 29,000 BTU for use in a domestic HW + radiant application. Could you send me submittal sheets and any other details on

Arctic Air to Water Heat Pumps

Domestic Hot Water The AltSource tank is equipped with an optional internal Heat Exchanger (HX) for domestic hot water production. This consists of 200 feet of 1/2” copper piping. Based on 120°F water tank temperatures this 200 ft of ½” OD cooper pipe, 26.2 sq/ft surface area and has a volume of 1.5 total gallons.

Because the efficiency of the heat pump is better at lower water temperatures, we recommend using the internal domestic hot water coil in a pre-heat arrangement. In this diagram the cold water enters the coil from the bottom and exists at about 95% of the tank setting temperature. Following this the warm water then goes to the primary tank or an on-demand water tank where it is topped up a few degrees to reach 120°F or more depending on the application. When sizing a heat pump with domestic hot water load please add about 10,000 BTU per person to the daily load. So, a house with 4 persons would need an extra 40,000 BTU per day. On an hourly bases this would be 1,667 BTU/hour over 24 hours.

What is a flow rate and what should I ask for? Consider how many of these needs you may have simultaneously to determine the maximum flow rate you require. For a home with 1 bathroom, we recommend 6-7 GPM; 2 bathrooms, 8 – 9 GPM; and 3+ bathrooms, 9-11 GPM. What is a flow rate and what should I ask for? Consider how many of these needs you may have simultaneously to determine the maximum flow rate you require. For a home with 1 bathroom, we recommend 6-7 GPM; 2 bathrooms, 8 – 9 GPM; and 3+ bathrooms, 9-11 GPM.

https://plumbestore.com/products/eco-king-52-stainless-steel-coil-tank?variant=40820050100277&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&srsltid=Ad5pg_GvtvxwqGw-r-NdmLPi-dtNOxGVEkE9--PY0lQMW7D3lHV6h7GzU2s

heat pump water heater for HW and radiant

http://www.civil.uwaterloo.ca/beg/archtech/hot_water_heater_furnace.pdf

like this but with heat pump water heater instead Heat pump for DHW+radiant.png

hybrid heat pump algorithms for resis.

https://www.greenbuildingadvisor.com/question/rheem-hybrid-pre-warm-mode-while-in-heat-pump-mode

https://www.nrel.gov/docs/fy14osti/52635.pdf

boiler

Lochinvar 120000 BTU

service 9/12/2019

Suburban Service Westwood 781-769-6694 2hrs $338 $169/hr

esp8266 hvac controller

3/8/

Soldered DHT11 onto an esp8266 to monitor attic humidity.

For the firmware in fs/www/iot/pio/pio-ardui/espboth/secstidif created config and saved as CONFIG_CYURD117attic_hum.cpp/h. Tricky bit was

3/7/22

replaced 700ma power supply with 2A (10W)

2/24/22

TODO problem with 74(mb) and 75(peri), furthest away devices. Constant wrong low readings followed by correct readings try new power supply first

Supply for the six 8266's and 7 relays blew today, flashing on and off. Replaced with same kind. It lasted since 11/19, 2 1/2 years, when that disastrous upgrade happened while I was sick from derm drug.

max power esp8266 170ma * 7 = 1672ma power for 8 relays

The "L" in SRC-05-SL-C means 0.36 Watts. Since Watts is Volts times Amps we can divide by Volts to get Amps:

0.36 / 5 = 0.072 = 72 mA per coil. * 8 = 575 mA

total power needed: 1672ma + 575ma =2247ma NOT 700ma

1/24/22

The design embedded in the wooden plates for all but the living room uses a tiny pcb soldered right to the esp8266 with the sensor haging out so as not to be overheated by the chip. This KICAD esp82single design can use espboth/secstidif with a CONF_CYURD074hvacMB.cpp like configuration. All other fixes should use this version. Flaky devices are the master bedroom and peri's study. For the master bedroom, re'flashing brought it back to life. Had trouble flashing. Turns out I tried 3 bad usb cables in a row so I thought it was windows 11. You can check for a working connection in DeviceManager. view/show_hidden_devices. CH340 is the driver for esp and I plugged it into CYURD001 and its listing under PORTS changed from greyed out to dark when a good cable/connection was in play.

current design

code and spec file in d://fs/www/iot/pio/pio-ardui/espBoth/secstdif

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