For most commercial and institutional buildings, conventional thinking is to design a boiler system to handle heating loads and a separate water heating system to satisfy domestic hot water demands. This is a relatively simple, straightforward approach. It may surprise you to learn that there are some huge benefits to utilizing a combined space and water heating plant.
Consider these three benefits of using condensing gas-fired space heating boilers with a plate and frame heat exchanger (P&F HX) for domestic water heating:
1. The total required heating capacity is reduced. By combining the space heating and domestic water heating loads onto the same equipment, the overall capacity may be reduced. See the graph from the ASHRAE HVAC Applications Handbook and the example numbers in red.
a. This is possible because of the following (ref: ASHRAE HVAC Applications Handbook Chapter 50):
i. Maximum space-heating requirements do not occur at the time of day when peak hot-water demands take place.
iii. It is common for an additional source of heat to be provided or a boiler capacity to be added to compensate for pickup and radiation losses. The pickup load cannot occur at the same time as the peak hot-water demand because the building must be brought to a comfortable temperature before the occupants use hot water.
2. Boiler plant efficiency may be increased. For condensing boilers, the lower the return water temperature, the higher the efficiency. The <60°F domestic cold water entering the P&F HX will help lower the temperature of the building return water even more before it enters the boilers, resulting in greater combustion efficiency.
3. No storage. If you are serving a laundry system, a large kitchen, or other application with large hot water dump loads, this does not apply. For most other standard commercial or institutional buildings, removing hot water storage tanks and replacing them with a P&F HX is beneficial because:
a. Storage tanks eventually leak. Some lining materials last longer than others, but, at some point, water chemistry will win the day and that storage tank will need to be replaced. This may be costly and impractical due to the installation location.
b. Storage-type water heaters fail more often than storage tanks. When you have a fire inside the storage vessel, you expose dissimilar materials to variations in temperature. At different expansion rates, materials and their bonds eventually fail.
c. Prevents stagnation and Legionella growth. Water maintained at certain temperatures within a storage tank or storage heater can create an environment favorable for the growth of the bacteria Legionella. By eliminating storage, this risk is greatly reduced.
Some products and technologies make this heating approach much simpler and more advantageous than in years past. As always, this method may not be appropriate for every application. If you would like to know if this combined space heating and domestic water heating strategy is right for your next project, contact our sales team today!
Kwa majengo mengi ya kibiashara na taasisi, kufikiri kawaida ni kubuni mfumo boiler kushughulikia mzigo wa joto na mfumo tofauti ya maji ya joto ili kukidhi mahitaji ya maji ya joto ya nyumbani. Hii ni mbinu rahisi, ya moja kwa moja. Unaweza kushangazwa kujua kwamba kuna faida kubwa katika kutumia kiwanda cha kuchemsha maji na nafasi. Kwa mfano, kuna faida tatu za kutumia boilers ya joto ya hewa ya gesi ya condensing na exchanger ya joto ya sahani na fremu (P&F HX) kwa joto la maji ya nyumbani. Jumla ya mahitaji ya uwezo wa joto hupunguzwa. Kwa kuchanganya mzigo wa joto la nafasi na maji ya joto ya nyumbani kwenye vifaa sawa, uwezo wa jumla unaweza kupunguzwa. Tazama picha ya ASHRAE HVAC Applications Handbook na nambari za mfano kwa rangi nyekundu. a. Kwa nini? Kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano, kwa mfano. mahitaji ya juu ya joto nafasi si kutokea katika wakati wa siku wakati kilele maji ya moto mahitaji kuchukua nafasi. iii. Ni kawaida kwa chanzo cha ziada ya joto kuwa zinazotolewa au uwezo boiler kuwa aliongeza ili kulipia pickup na mionzi hasara. Pigo la kupakua haliwezi kutokea wakati huo huo kama mahitaji ya maji ya moto ya kilele kwa sababu jengo lazima liletwe kwa joto la starehe kabla ya wakazi kutumia maji ya moto. 2. Uwezekano wa kupata Boiler kiwanda ufanisi inaweza kuongezeka. Kwa boilers condensing, chini ya joto la maji ya kurudi, juu ya ufanisi. Maji baridi ya ndani ya 60 ° F kuingia P & F HX itasaidia kupunguza joto la maji ya kurudi ya jengo hata zaidi kabla ya kuingia boilers, na kusababisha ufanisi mkubwa wa kuchoma. 3. Uwe na mtazamo wa kweli Hakuna kuhifadhi. Ikiwa unahudumia mfumo wa kufulia nguo, jikoni kubwa, au matumizi mengine yenye mizigo mikubwa ya maji ya moto, hii haitumiki. Kwa majengo mengine ya kawaida ya kibiashara au taasisi, kuondoa matangi ya kuhifadhi maji ya moto na kuibadilisha na P&F HX ni faida kwa sababu: Hatimaye, matangi ya kuhifadhi maji huvuja. Vifaa fulani vya kufunika vinadumu kwa muda mrefu kuliko vingine, lakini wakati fulani, kemikali ya maji itashinda na tangi hilo la kuhifadhi litahitaji kubadilishwa. Hii inaweza kuwa ghali na isiyofaa kutokana na eneo la ufungaji. b. Vipuli vya maji vya kuhifadhi vinashindwa mara nyingi kuliko matangi ya kuhifadhi. Wakati moto unapoingia ndani ya chombo cha kuhifadhi, unaweka vitu tofauti-tofauti chini ya mabadiliko ya halijoto. Kwa viwango tofauti vya kupanuka, vifaa na vifungo vyao hatimaye vinashindwa. c. Inazuia kusitawi na ukuaji wa Legionella. Maji yaliyohifadhiwa kwa joto fulani ndani ya tangi la kuhifadhi au kichocheo cha kuhifadhi yanaweza kuunda mazingira mazuri kwa ukuzi wa bakteria ya Legionella. Kwa kuondoa kuhifadhi, hatari hii hupunguzwa sana. Baadhi ya bidhaa na teknolojia kufanya mbinu hii ya joto rahisi sana na faida zaidi kuliko katika miaka ya zamani. Kama kawaida, njia hii inaweza kuwa si sahihi kwa kila maombi. Kama unataka kujua kama hii mchanganyiko nafasi ya joto na maji ya joto ya nyumbani mkakati ni haki kwa ajili ya mradi wako ijayo, kuwasiliana na timu yetu ya mauzo leo!